document_title: Walk Like a Man (The Four Seasons song)

question_text: who sang walk like a man in the 80's

question_tokens: who sang walk like a man in the 80 's

text: Walk Like a Man (The Four Seasons song)

text: The Four Seasons' version[edit]

text: The song features the counterpoint of Nick Massi's bass voice and the falsetto of lead singer Frankie Valli. It was their third number one hit, initially reaching the top of the Billboard Hot 100 on March 2, 1963, remaining there for three weeks.  "Walk Like a Man" also went to number three on the R&B singles chart [2]

text: During the sessions that produced the hit recording, the fire department received an emergency call from the Abbey Victoria Hotel (the building that housed the Stea-Phillips Recording Studios). As producer Bob Crewe was insisting upon recording the perfect take, smoke and water started to seep into the studio; the room directly above the studio was on fire, but Crewe had blocked the studio door. He continued recording until a few firemen used their axes on the door and pulled Crewe out.[3]

text: Cover versions of the song have been recorded by other musicians such as the Mary Jane Girls (1986), Divine (1985), Dreamhouse and Jan & Dean (1963) off the album Jan & Dean Take Linda Surfin. Plastic Bertrand did a cover version in French, entitled C'est Le Rock 'n' Roll (1978) and Hungarian band Bon Bon also covered the song with the title Sexepilem (1999).

text: The song features prominently in the 1996 film Sleepers.

text: The song "Walk Like a Man" is part of The Rock and Roll Hall of Fame's 500 Songs that Shaped Rock and Roll list.[4]

text: Divine cover[edit]

text:
"Walk Like a Man"Single by DivineReleased
1985Format
CD single, Maxi singleGenre
Hi-NRG[5]Label
Proto Records, Liberation RecordsSongwriter(s)
Bob Crewe, Bob GaudioDivine singles chronology

"T Shirts and Tight Blue Jeans" (1984)

"Walk Like a Man" (1985)

"Twistin' The Night Away" (1985)

text: Divine covered "Walk Like a Man" and released it as a single from the album Maid in England in 1985.

text: Track listing[edit]

text:
"Walk Like a Man" – 3:50
"Man Talk" – 3:23

text: Charts[edit]

text:
Chart (1985)

Peakposition

Australian Singles Chart[6]

75

German Singles Chart[7]

52

Irish Singles Chart

23

Swiss Singles Chart[8]

28

UK Singles Chart[9]

23


document_title: Pilot (Pretty Little Liars)

question_text: when was the first episode of pretty little liars filmed

root

text: Pilot (Pretty Little Liars)

text: Pilot[edit]

text: In Rosewood, Pennsylvania (2009). Four friends get together in a homely barn, drinking and having fun. At one point, a noise outside the barn scares them. The girls slowly make their way to the barn door, and a blonde girl gives them a fright, screaming. The blonde is after revealed to be Alison DiLaurentis, the clique's leader. The five then either sit or lie down and return to playful activities, falling asleep shortly after. During nightfall, Alison disappears and Spencer Hastings tries to look for her in the night. Aria Montgomery then wakes up and finds Spencer arriving back in the barn, who tells her and the others that she did not find Alison anywhere.

tag: p

text: One year later, it is revealed that Alison mysteriously vanished that night, and the girls went separate ways. Aria and her parents traveled for a year to Iceland; Hanna Marin underwent a complete style transformation, becoming the it-girl of Rosewood's social scene, and is friends with Mona Vanderwaal, who used to be bullied by Alison; Emily Fields focused on her swimming skills, hiding that she's attracted to girls and was in love with Alison; and Spencer focused on her studies and struggled to become Rosewood High's number one student.

text: The Montgomery returns to Rosewood after spending a year in Iceland, and Aria finds herself unable to adapt again to the town's mediocrity. Ella and Byron, Aria's parents, are happy together again after a crisis they had in the past, while Mike, Aria's younger brother, quickly settles himself in the lacrosse team. In an attempt to refresh her mind, she goes to a pub to drink and meets a guy there who also likes literature. They feel connected and make out in the pub's bathroom. On the first day of class, she discovers he's her new English teacher, Ezra Fitz. Aria receives a threatening message from someone who identifies as 'A', and who apparently knows about hers and her father's secrets.

text: At the Rosewood Mall, Hanna and Mona shoplifts and camera footage catch Hanna, leading her mother to sleep with Detective Darren Wilden to release her daughter. Spencer prepares for a family dinner in which her sister Melissa introduces her fiancée Wren to the Hastings. Spencer discovers that Melissa and Wren will live in the barn that Spencer has gone on vacancy reforming and it irritates her. Meanwhile, Spencer discovers that she feels something for Wren. Emily's mother asks her to drop a welcome basket to the family which just moved to Rosewood and is living in the old DiLaurentis residence. Emily is reluctant, but ends up meeting with Maya who is the daughter of the St. Germain. They quickly befriend. Ashley, Hanna's mother, is still suffering from her divorce, and is having an affair with the detective who released Hanna. Is also revealed that Aria's father had an affair with one of his students in the past, Meredith, just like what's happening between Aria and Ezra. Spencer receives a message from 'A' which makes her remember she kissed Ian Thomas, Melissa's former boyfriend, in the past. Emily and Hanna also receive threatening message from 'A'.

text: They soon suspect Alison is 'A', until her body is found in the St. Germain residence and the town gets shocked. At her funeral, Jessica DiLaurentis meets the girls and places her in the front row. The girls worry when Jenna Marshall — a classmate who was blinded in an incident involving the four girls and Alison — and her stepbrother Toby, appear in the funeral. After, outside the church, the girls receive one more text: I'm still here bitches. And I know everything -A.

text: Production[edit]

text: "Pilot" was written by series' showrunner and main collaborator I. Marlene King and directed by Lesli Linka Glatter. On January 27, 2010, ABC Family picked up the series for 10 episodes, set to premiere in June 2010.[1] The theme song for Pretty Little Liars opening is "Secret" by The Pierces, which was suggested by one of the show's stars, Ashley Benson.[2]

text: Casting[edit]

text: ABC Family began casting for a Pretty Little Liars television pilot in October 2009.[3] Lucy Hale was cast as Aria Montgomery in the project, followed by Troian Bellisario as Spencer Hastings and Ian Harding as Ezra Fitz in November 2009.[4] In December 2009, The Futon Critic confirmed the casting of Ashley Benson as Hanna Marin and Shay Mitchell as Emily Fields, as well as the addition of Laura Leighton as Ashley Marin, Nia Peeples as Pam Fields, Roark Critchlow as Tom Marin, and Bianca Lawson as Maya.[5][6] Mitchell had initially auditioned for the role of Spencer and then tried for Emily.[7] The Hollywood Reporter also noted that Torrey DeVitto and Sasha Pieterse landed recurring roles in the pilot.[6] The Alloy Entertainment website later confirmed that Pieterse would be playing Alison DiLaurentis and DeVitto would be Melissa Hastings, also mentioning the casting of Janel Parrish as Mona Vanderwaal.[8] Initially, Alexis Denisof was cast to be Aria Montgomery's father Byron. In April 2010, the role of Aria's father Byron was recast with Chad Lowe,[9][10] and Holly Marie Combs was cast as Aria's mother Ella. Jenna Marshall is played by Tammin Sursok.[11] The actors who played Ian Thomas and Toby Cavanaugh in this episode were after replaced by Ryan Merriman and Keegan Allen, respectively.

text: Filming[edit]

text: After the pilot was shot in Vancouver, filming for the rest of the series has since moved to Los Angeles.[12][13] The series is primarily filmed at the Warner Bros. studio and backlot in the city of Burbank (near Los Angeles).[14]

text: Reception[edit]

text: Ratings[edit]

text: The pilot was broadcast on June 8, 2010.[15] It was watched by 2.47 million viewers, scoring a 0.9 rating in the 18-49 demographic.[16]

text: Reviews[edit]

text: "Pilot" was received with mixed opinions, although the series has gotten a more positive critique over its progression. Metacritic gave the pilot episode 52 out of 100, based upon 14 critical reviews.[17] The New York Daily News gave the show a positive review, commenting that it "makes most popular vampire romances look anemic", while concluding, "Pretty Little Liars could go in several directions, including mundane teen clichés. It's got an equally good shot at making us care about these imperfect pretty girls."[18] A writer on Terror Hook has stated that " 'Pretty Little Liars' gets off to a very promising start. Great production all around, the writing keeps the viewer on their toes, and the acting just reinforces it. The overall mystery of the show in the end is dark and unpredictable, even stepping into the slasher film realm."[19] The New York Post gave the show three out of five stars, stating, "OK, so we've established that there is no socially redeeming value in this series and that your kids shouldn't watch it if they are too young and impressionable. But if you can distract them enough to miss the first 15 minutes, the show isn't half-bad. Actually, it is half-good, if that makes sense."[20] The Los Angeles Times wrote that the series is "one of those shows that manages to mildly, and perhaps unintentionally, spoof its genre while fully participating in it, and that's not a bad thing at all."[21]


document_title: List of NCAA Division I men's basketball career scoring leaders

question_text: who averaged the most points in college basketball history

text: In basketball, points are the sum of the score accumulated through free throw or field goal.[1] In National Collegiate Athletic Association (NCAA) Division I basketball, where a player's career is at most four seasons long, it is considered a notable achievement to reach the 1,000-points scored threshold. In even rarer instances, players have reached the 2,000- and 3,000-point plateaus (no player has ever scored 4,000 or more points at the Division I level). The top 25 highest scorers in NCAA Division I men's basketball history are listed below. The NCAA did not split into its current divisions format until August 1973.[2] From 1906 to 1955, there were no classifications to the NCAA nor its predecessor, the Intercollegiate Athletic Association of the United States (IAAUS).[2] Then, from 1956 to spring 1973, colleges were classified as either "NCAA University Division (Major College)" or "NCAA College Division (Small College)".[2][3]

text: Some of the top 25 scorers in Division I history played before the three-point line was officially instituted in 1986–87. All of the players with a dash through the three-point field goals made column were affected by this rule. Hank Gathers of Loyola Marymount is the only three-point shot era player on this list who did not make a single three-point shot. From the 1986–87 season through the 2007–08 season, the three-point perimeter was marked at 19 ft 9 in (6.02 m) for both men's and women's college basketball.[4] On May 3, 2007, the NCAA men's basketball rules committee passed a measure to extend the distance of the men's three-point line back to 20 ft 9 in (6.32 m); the women's line would remain at the original distance until it was moved to match the men's distance effective in 2011–12.[4]

text: Additionally, several of the players on this list played during an era when college freshmen were ineligible to compete at the varsity level and were forced to participate on either freshman or junior varsity teams. Since freshman and junior varsity points do not count toward official NCAA records, three players—Pete Maravich, Oscar Robertson and Elvin Hayes—only had three seasons to compile their totals. Larry Bird redshirted (sat out) his freshman year, and therefore, like Maravich, Robertson, and Hayes, his totals also cover only three seasons (though in Bird's case, unlike the others, it was his own choice not to play a fourth season at the college level). With the added benefits of a three-point line and a full extra year of varsity eligibility, their already-historical statistics would have been much higher. Maravich, a guard from LSU, not only owns the three highest single season averages in Division I history, but also the highest career total. Remarkably, he scored 3,667 points (over 400 more than the next closest player) in a mere 83 games. His record is considered nearly unbreakable; the only player who could have potentially overtaken him as the top scorer in Division I history is Stephen Curry of Davidson, who had scored 2,635 points through his first three seasons of college basketball. However, Curry opted to forgo his final year of NCAA eligibility and moved on to the National Basketball Association (NBA) following his junior season in 2008–09.

text: Five players on this list are enshrined in the Naismith Memorial Basketball Hall of Fame: Pete Maravich,[5] Oscar Robertson,[6] Elvin Hayes,[7] Larry Bird[8] and David Robinson.[9]

text: Key[edit]

text:
Pos.
G
F
C
Ref.

Position
Guard
Forward
Center
References

*

Elected to the Naismith Memorial Basketball Hall of Fame

Team (X)

Denotes the number of times a player from that team appears on the list

tag: table

text: Career scoring leaders[edit]

text:
Player

Pos.

Team

Careerstart

Careerend

Gamesplayed

Field goalsmade

3-point field  goals made

Free throws made

Points

PPG

Ref.

Pete Maravich*

G

LSU

1967

1970

83

1,387

—

893

3,667

44.2

[10]

Freeman Williams

F/G

Portland State

1974

1978

106

1,369

—

511

3,249

30.7

[11]

Lionel Simmons

F

La Salle

1986

1990

131

1,244

56

673

3,217

24.6

[12]

Alphonso Ford

G

Mississippi Valley State

1989

1993

109

1,121

333

590

3,165

29.0

[13]

Doug McDermott

F

Creighton

2010

2014

145

1,141

274

594

3,150

21.7

[14]

Harry Kelly

F

Texas Southern

1979

1983

110

1,234

—

598

3,066

27.9

[15]

Keydren Clark

G

Saint Peter's

2002

2006

118

967

435

689

3,058

25.9

[16]

Hersey Hawkins

G

Bradley

1984

1988

125

1,100

118

690

3,008

25.5

[17]

Oscar Robertson*

G

Cincinnati

1957

1960

88

1,052

—

869

2,973

33.8

[18]

Danny Manning

F

Kansas

1984

1988

147

1,216

10

509

2,951

20.1

[19]

Alfredrick Hughes

G

Loyola (IL)

1981

1985

120

1,226

—

462

2,914

24.3

[20]

Elvin Hayes*

C/F

Houston

1965

1968

93

1,215

—

454

2,884

31.0

[21]

Tyler Hansbrough

F

North Carolina

2005

2009

142

939

12

982

2,872

20.2

[22]

Larry Bird*

F

Indiana State

1976

1979

94

1,154

—

542

2,850

30.3

[23]

Otis Birdsong

G

Houston (2)

1973

1977

116

1,176

—

480

2,832

24.4

[24]

Kevin Bradshaw

G

Bethune-Cookman / U.S. International

1987

1991

111

1,027

132

618

2,804

25.3

[3]

Allan Houston

G/F

Tennessee

1989

1993

128

902

346

651

2,801

21.9

[25]

J. J. Redick

G

Duke

2002

2006

139

825

457

662

2,769

19.9

[26]

Hank Gathers

F/C

Southern California /Loyola Marymount

1985

1990

117

1,127

0

469

2,723

23.3

[27]

Tyler Haws

G

BYU

2009

2015[n 1]

139

917

162

724

2,720

19.6

[28]

Reggie Lewis

F

Northeastern

1983

1987

122

1,043

30

592

2,709

22.2

[29]

Daren Queenan

G/F

Lehigh

1984

1988

118

1,024

29

626

2,703

22.9

[30]

Byron Larkin

G

Xavier

1984

1988

121

1,022

51

601

2,696

22.3

[31]

Bo McCalebb

G

New Orleans

2003

2008

128

977

115

610

2,679

20.9

[32]

David Robinson*

C

Navy

1983

1987

127

1,032

1

604

2,669

21.0

[33]

text: All-time conference scoring leaders[edit]

text: The following list contains current and defunct Division I conferences' all-time scoring leaders. The "conference founded" column indicates when each respective conference first began intercollegiate athletic competition, not necessarily when they began basketball. For example, the Great West Conference was established as a football-only conference in 2004 but became an all-sports conference in 2008 (with basketball actually beginning in 2009–10).[34] Also note that some of the schools on this list are no longer in the conference in which they are identified. Utah, for instance, is currently a member of the Pac-12 Conference, but when Keith Van Horn set the scoring record they were still a member of the Western Athletic Conference. Similarly, BYU is currently in the West Coast Conference, but their final four seasons in the Mountain West Conference were the years in which Jimmer Fredette played at the school and set that conference's scoring record.

text:
Conference

Conferencefounded

Conferencedisbanded

Player

School

Careerstart

Careerend

Points

Ref.

America East

1979

—

Reggie Lewis

Northeastern

1983

1987

2,709

[35]

American Athletic

2013[n 2]

—

Rob Gray

Houston

2015

2018

1,710

[38]

American South

1987

1991

Kevin Brooks

Southwestern Louisiana

1987

1991

2,294

Atlantic 10

1976

—

Mark Macon

Temple

1987

1991

2,609

[39]

ACC

1953

—

Tyler Hansbrough

North Carolina

2005

2009

2,872

[40]

Atlantic Sun

1978

—

Willie Jackson

Centenary

1980

1984

2,535

[41]

Big 12

1996

—

Buddy Hield

Oklahoma

2012

2016

2,291

[42]

Big East

1979[n 2]

—

Troy Bell[n 3]

Boston College

1999

2003

2,632

[44]

Big Eight

1907

1996

Danny Manning

Kansas

1984

1988

2,951

[45]

Big Sky

1963

—

Bogdan Bliznyuk

Eastern Washington

2014

2018

2,169

[46]

Big South

1983

—

Reggie Williams

VMI

2004

2008

2,556

[47]

Big Ten

1896

—

Calbert Cheaney

Indiana

1990

1993

2,613

[48]

Big West

1969

—

Lucious Harris

Long Beach State

1989

1993

2,312

[49]

CAA

1982

—

David Robinson*

Navy

1983

1987

2,669

[50]

C-USA

1995

—

Stefon Jackson

UTEP

2005

2009

2,456

[51]

East Coast

1958

1994

Daren Queenan

Lehigh

1984

1988

2,703

Great Midwest

1990

1995

Erwin Claggett

Saint Louis

1991

1995

1,910

[52]

Great West

2004

2013

Chris Flores

NJIT

2009

2013

1,726

Horizon

1979

—

Alfredrick Hughes

Loyola (IL)

1981

1985

2,914

[53]

Ivy

1901

—

Bill Bradley*

Princeton

1962

1965

2,503

[54]

MAAC

1980

—

Lionel Simmons

La Salle

1986

1990

3,217

[55]

Metro

1975

1995

Bimbo Coles

Virginia Tech

1986

1990

2,484

[56]

MAC

1946

—

Bonzi Wells

Ball State

1994

1998

2,485

[57]

MEAC

1970

—

Tom Davis

Delaware State

1987

1991

2,275

[58]

Missouri Valley

1907

—

Hersey Hawkins

Bradley

1984

1988

3,008

[59]

Mountain West

1999

—

Jimmer Fredette

BYU

2007

2011

2,599

[60]

NEC

1981

—

Terrance Bailey

Wagner

1983

1987

2,591

[61]

OVC

1948

—

Henry Domercant

Eastern Illinois

1999

2003

2,602

[62]

Pac-12

1959

—

Don MacLean

UCLA

1988

1992

2,608

[63]

Patriot

1986

—

C. J. McCollum

Lehigh

2009

2013

2,361

[64]

SEC

1933

—

Pete Maravich*

LSU

1967

1970

3,667

[65]

Southern

1921

—

Stephen Curry

Davidson

2006

2009

2,635

[66]

Southland

1963

—

Joe Dumars*[n 4]

McNeese State

1981

1985

2,607

[68]

Summit

1982

—

Caleb Green

Oral Roberts

2003

2007

2,504

[69]

Sun Belt

1976

—

Bo McCalebb

New Orleans

2003

2008

2,679

[70]

Southwest

1914

1996

Terrence Rencher

Texas

1991

1995

2,306

[71]

SWAC

1920

—

Alphonso Ford

Mississippi Valley State

1989

1993

3,165

West Coast

1952

—

Hank Gathers

Loyola Marymount

1987

1990

2,490[n 5]

[72]

WAC

1962

—

Keith Van Horn

Utah

1993

1997

2,542

[73]

text: Footnotes[edit]

text:
Jump up ^ After playing as a freshman in 2009–10, Haws spent two years on a Mormon mission and did not play his sophomore season until 2012–13.

^ Jump up to: a b The original Big East Conference, founded in 1979 with basketball competition starting at that time, split along football lines in July 2013. The seven schools that did not sponsor Division I FBS football reorganized as a new Big East Conference, while the FBS football schools that had not left for other conferences, plus several new members, began operating as the American Athletic Conference. The American now considers its basketball history to have begun with the 2013 split,[36] while the current Big East maintains the basketball history of the original Big East.[37]

Jump up ^ The Big East Conference recognizes Lawrence Moten, who played at Syracuse between 1991 and 1995, as its all-time conference scoring leader, using the criterion of points scored in regular-season conference games only. Moten scored 1,405 points in games that counted toward the record.[43] Troy Bell, who is technically second on the list with 1,388 points, scored more career points than Moten when all games are taken into account. The above conference scoring leaders list uses overall career totals, not conference-career totals, as its criterion.

Jump up ^ The Southland Conference recognizes Dwight "Bo" Lamar, who played at Southwestern Louisiana (now Louisiana) between 1968 and 1972, as their all-time conference scoring leader, using the criterion of points scored against conference opponents only.[67] He scored 1,054 points in conference games.[67] Additionally, Southwestern Louisiana did not join the Southland Conference until 1971, so all of Lamar's points prior to then do not count toward Southland Conference scoring. Joe Dumars, who is technically second on the list with 819 points, actually scored more career points than Lamar since McNeese State was a member of the Southland Conference for the duration of Dumars' career. The above conference scoring leaders list uses overall career totals, not conference-career totals, as its criterion.

Jump up ^ Hank Gathers' scoring total in this table includes only games played for WCC member Loyola Marymount; he played his freshman season of 1985–86 at USC in what was then known as the Pacific-10 Conference. He transferred from USC after that season; after sitting out the 1986–87 season due to NCAA transfer rules, he played at Loyola Marymount until his death during his senior season in 1990.

tag: ol


document_title: The Roosevelt Hotel (Manhattan)

question_text: who owns the roosevelt hotel in new york

text: The Roosevelt Hotel (Manhattan)

text: Description[edit]

text: There are a total of 1,015 rooms in the hotel, including 52 suites. The 3,900 square feet (360 m2) Presidential Suite has four bedrooms, a kitchen, formal living and dining areas, and a wrap-around terrace. The rooms are traditionally decorated, with mahogany wood furniture and light-colored bed coverings.

text: There are several eateries within the hotel. They include:

text:
The "Roosevelt Grill", which serves American food and regional specialties for breakfast, lunch, and dinner.
The "Madison Club Lounge", a bar and lounge which has a 30-foot (9.1 m) mahogany bar and features stained glass windows and a pair of fireplaces.
"Vander Bar", a bar that serves classic, hand-crafted cocktails and creative gastro-pub fare like the Vander Burger and Korena Steak Salad.[2]

tag: ul

text: The Roosevelt has 30,000 square feet (2,800 m2) of meeting and exhibit space, including two ballrooms and 17 additional meeting rooms ranging in size from 300–1,100 sq ft (100 m2). It offers a business center which provides Internet access, fax services, secretarial services, copy services, and shipping services. Other services include a concierge, a 24-hour fitness center, safety deposit boxes, valet laundry, valet or self-parking, and 15 retail tenants.[3]

text: History[edit]

text: The Roosevelt hotel, opened on September 23, 1924, was built by Niagara Falls businessman Frank A. Dudley and operated by the United Hotels Company.[1] The hotel was designed by the architecture firm George B. Post & Son, and leased from The New York State Realty and Terminal Company, a division of the New York Central Railroad. The hotel, built at a cost of $12,000,000[1] (equivalent to $167,697,000 in 2016), was the first to incorporate store fronts instead of lounges in its sidewalk facades due to the Prohibition era. The Roosevelt Hotel was at one time linked with Grand Central Terminal by way of an underground passage that connected the hotel to the train terminal. The Roosevelt housed the first guest pet facility and child care service in The Teddy Bear Room and had the first in-house doctor.

text: Conrad Hilton purchased the Roosevelt in 1943 calling her "a fine hotel with grand spaces" and even though he eventually owned many other hotels in New York, including The Plaza and The Waldorf Astoria, he chose the Roosevelt's Presidential Suite as his home. In 1947, the Roosevelt became the first hotel to have a television set in every room.

text: Beginning in 1979, the hotel was leased by the Pakistan International Airlines through its investment arm PIA Investments Ltd. ("PIA"), with an option to purchase the building after 20 years. Prince Faisal bin Khalid bin Abdulaziz Al Saud of Saudi Arabia was one of the investors in the 1979 deal.[4] In 1999, PIA exercised their option and bought the hotel for $36.5 million, after a legal battle with owner Paul Milstein, who claimed it was worth much more.[5] In 2005, PIA bought out its Saudi partner in a deal that included the prince's share in Hôtel Scribe in Paris in exchange for $40 million and PIA's share of the Riyadh Minhal Hotel (a Holiday Inn located on property owned by the prince).[3] PIA has since controlled 99 percent interest in the hotel, while the Saudis have only 1 percent.

text: In July 2007, after a major $65 million (equivalent to $75,077,000 in 2016) renovation, PIA announced that it was putting the hotel up for sale.[6] The increasing profitability of the hotel, at the same time as the airline itself started to incur massive losses, resulted in the sale being abandoned.[7] On January 1, 2011 The Roosevelt Hotel's General Manager stated the hotel is once again undergoing extensive renovations but will remain open during the process.

text: Notable events[edit]

text: Guy Lombardo performed "Auld Lang Syne" for the first time in the hotel’s Roosevelt Grill, which was open from 1927 to 1958, and Lawrence Welk began his career at the Roosevelt Hotel in the summers while Lombardo took his music to Long Island. Music was piped live into each room via radio. Hugo Gernsback (of Hugo Award fame) started WRNY from a room on the 18th floor of The Roosevelt broadcasting live via a 125-foot tower on the roof.

text: From 1943 to 1955 the Roosevelt Hotel served as the New York City office and residence of Governor Thomas E. Dewey. Dewey's primary residence was his farm in Upstate New York, but he used Suite 1527 in the Roosevelt to conduct most of his official business in the city. In the famous 1948 presidential election, Dewey, his family, and staff listened to the election returns in Suite 1527 of the Roosevelt; in the election Dewey lost to incumbent President Harry Truman in one of the greatest political upsets in American history.

text: Though the civil rights act of 1964 banned discrimination in public accommodations, the Men's Grill at the Roosevelt refused to admit women until a New York City law was passed in 1970. The law prohibited banning women by places that were "sexegrated" on the grounds that, though they welcomed the public, they were private clubs.

text: In popular culture[edit]

text: Film:

text:
The Taking of Pelham 123
The French Connection
Hanky Panky
Quiz Show
Wall Street
Maid in Manhattan
1408
The Dictator
Men in Black 3
Man on a Ledge
Broken City

text: Music:

text:
The Hotel was the setting for Rascal Flatts' Christmas music video "I'll Be Home For Christmas".
According to musician John Prine, the country classic "You Never Even Called Me by My Name" was written by Steve Goodman and Prine at a room desk in the Roosevelt Hotel. Prine refused official co-writing credit, and in 1975 it went on to become a Top Ten hit and signature song for David Allan Coe.

text: Television:

text:
In Season 2 of Mad Men, Don Draper lives at The Roosevelt Hotel for multiple episodes while he is having marital troubles, though all scenes were shot in Los Angeles.
In the opening credits for Travel Channel's Hotel Impossible, host Anthony Melchiorri can be seen standing in the lobby of the Roosevelt Hotel. However, it was never featured as a struggling hotel in any episode. The opening credits give "special thanks" to the Roosevelt.[8]
In season 1, episode 6 of HBO's The Leftovers, Nora attends a conference in New York City where she is to be a panelist. Her ID has been stolen and the thief causes trouble for her in the hotel. The lobby, the bar area, the surrounding raised restrooms area and hallway, and even the familiar large square patterned room cushions are on the show.


document_title: Joey Potter

question_text: who did joey lose virginity to on dawson's creek

question_tokens: who did joey lose virginity to on dawson 's creek

text: Joey Potter

text: Fictional biography[edit]

text: Background[edit]

text: Joey has been friends with Dawson Leery since they were very young. She lives with her older sister, Bessie, Bessie's son Alexander and (sometimes) boyfriend, Bodie. Her father Mike, is in and out of prison for drug trafficking. Her mother, Lillian, died of breast cancer when Joey was thirteen. Joey is also the only character to appear in every episode of the series.

text: Season 1[edit]

text: In season one, Joey is the "girl next door." She is confused by her growth into a teenager and her developing feelings for her longtime best friend Dawson, who she also admitted is her soulmate. She immediately becomes jealous when Jen Lindley arrives and steals Dawson away from her. She is intimidated by Jen, who grew up in New York and does not know how to compete. She lives with her pregnant sister Bessie, and she works for her at the Ice House, the Potter family restaurant. She is frustrated with having to deal with work and taking care of her sister along with significant helpings of teenage angst. Nonetheless, Joey manages to be helpful with the birth of Bessie's son, Alexander, as does their critical neighbor, Evelyn Ryan. One day she is convinced to compete in the beauty pageant, which she does so that she can win the cash prize. But instead of winning the contest, she wins Dawson's heart, as he finally sees past his best friend image, and realizes that he has strong romantic feelings towards her. At the end of the season, she finds herself with the opportunity of going to Paris for a year, but rejects it in favor of staying in Capeside with Dawson after she and Dawson kiss.

text: Season 2[edit]

text: At the start of the season, she and Dawson are a couple and things start out well, but Joey begins to think that she is losing her identity, as she can't see where Dawson ends and she begins. During a full moon, the new guy in town, Jack McPhee, kisses her. Dawson finds out during a school dance. After a huge argument, Joey decides to break up with him, even though for the first time they both say that they love each other. She says that she wants to "find herself," and so she breaks up with him.

text: Joey and Jack begin dating afterward but the relationship ends just as quickly when Jack realizes that he's gay. Joey's father is released from prison and comes back into her life. At first this change is uneasy, but they heal the rift between them and she gets back together with Dawson. However, Dawson finds out that Joey's father is dealing cocaine. After a fire at the restaurant which was started by rivals of Joey's father, Dawson tells his parents who advise him he needs to go to the police. He tells Joey instead. He convinces her to wear a wire, and get a confession from her father so that nothing like the fire will happen again. She gets the confession from her father and shows him the wire. Knowing that she had betrayed her father, she is understandably heartbroken and angry with Dawson. She breaks up with him and tells him she doesn't even want to know him and that she will never forgive him.

text: Season 3[edit]

text: After Dawson returns from visiting his mom over the summer, Joey offers herself to him but Dawson rejects her. Joey flees and Dawson asks Pacey Witter to keep an eye on her. As the season progresses, it becomes obvious that Pacey and Joey's friendship evolves into something deeper. Joey has a brief relationship with a college student, A.J. Moller (Robin Dunne). This relationship makes Pacey jealous and forces him to confront his true feelings for Joey. After months of build up, Pacey finally kisses Joey after she confides in him that he and Dawson are the only ones to "have ever known her in a way that no one else does." Joey initially is angry when Pacey kisses her; however, later she comes to realize that she may also have feelings for him, as well.

text: Joey took a job at a Logan's Marina, where she received unwanted sexual advances from her supervisor, Rob Logan.

text: During a trip to the home of Dawson's aunt, Gwen (Gail's sister), Joey and Pacey confront their feelings for one another. Joey confesses that being around Pacey makes her feel more alive resulting in Pacey kissing her again. Pacey tells Joey she needs to figure out what she wants and leaves. Joey stops him and pulls Pacey into a kiss, having made her choice, but Dawson's aunt Gwen sees this happen. After this realization, they begin a secret romantic relationship.

text: When Dawson finds out about Joey and Pacey's relationship, he is furious, and the friendship between the three is never the same again. Dawson gives Joey an ultimatum- him or Pacey. Joey stupidly pulls back from Pacey in an effort to mend his and her friendship with Dawson. Dawson, however, sees Pacey as his enemy and opponent in winning Joey's heart. Dawson tries his best to win Joey back, including throwing an alternative prom with Joey as his date. However, Dawson witnesses Joey and Pacey share a romantic dance before the night is over.

text: In the season finale, Joey comes to realize that while she's just fearful of losing her oldest friend, Dawson, she has fallen in love with Pacey. With Dawson's urging, Joey rushes off to tell Pacey that she loves him before he departs for a summer at sea on his boat. She joins Pacey on his boat and the two then sail off into the sunset.

text: Season 4[edit]

text: Joey and Pacey return to Capeside from their summer at sea in the fourth season, and are quickly brought back to reality when they must confront the events of the past year and the subsequent fallout. Joey is eager to mend fences, though Dawson is still hurt by what happened. Pacey's relationship with Dawson never quite recovers until the end of the series, though the two are civil and acknowledge a shared history and group of friends.

text: Joey and Dawson get chosen as class couple as a practical joke by Drue Valentine. Also, Pacey has returned to academic probation while Joey dreams of admittance to the prestigious Worthington College in Boston. On a ski trip with the senior class, Pacey and Joey finally sleep together for the first time. However, when Dawson questions her, she lies about losing her virginity. Pacey finds out about the lie and is unsettled. He is further disturbed when Joey accepts money from Dawson to attend Worthington.

text: After Joey returns from New York with Jen, she discovers from Gretchen that Pacey was arrested for public drunkness and that she also believes she may be pregnant. Bessie soon finds out that Joey believes she may be pregnant at Gail's baby shower, and Bessie argues with her about not being ready to have a baby, and having an immature boyfriend who would never cope with a child. Joey later defends herself by saying that whatever happens in her life will be different. Joey later does a test and finds out she is not pregnant, but the situation draws the sisters close together. When Joey finally reaches Pacey on the phone, she lies about the pregnancy scare and is disappointed that Pacey didn't tell her about his arrest.

text: Pacey soon begins to feel insecure about Joey's success and their relationship despite her insistence that her future lies with him, believes that he isn't good enough for her, and that their futures are worlds apart. At their senior prom, Pacey breaks up with Joey, who is devastated. The season ends with Joey headed to Worthington and Pacey to another summer at sea.

text: At the end of the season, as Dawson is preparing to leave Capeside for Los Angeles, in a scene reminiscent of Season One's ending, Dawson and Joey share a kiss.

text: Season 5[edit]

text: In season five, Joey attends Worthington University in Boston, where she meets and befriends her roommate Audrey Liddell. Joey is studying English Literature, and for a time starts seeing her college professor, David Wilder.

text: Throwing everyone for a loop, Mitch is killed in a car accident leaving Gail, Dawson and baby Lily behind. Having been a witness to her mother's painful last days, Joey thinks that she can help Dawson through the process of grieving for his father. She attends Mitch's funeral, but is rejected when she tries to help Dawson deal with his whirl of emotions. Upon returning to her dorm room in Boston, a crying Joey is comforted by Audrey. While Jen convinces Dawson to go to counseling, Joey catches Jack in a 'bid' to get one of his frat brothers in bed with Audrey during the fraternity's Winter Formal.

text: Joey later joins the band, Aggressive Mediocrity, as lead singer with Jen's cheating ex, Charlie Todd (Chad Michael Murray). They embark on a whirlwind romance before she tells him to leave to pursue his dream of being a touring musician. She has an unforgettable run-in with a mugger, who luckily for her, gets hit by a car shortly after robbing her at gunpoint. However, when she is requested to be at his side in the hospital, Joey discovers that the mugger is also a drug addict, and has a young daughter, Sammie, with his wife, Grace. When the mugger dies with Joey at his side, she returns to the waiting room, all of her belongings returned, including the money. Thinking of Sammie, whose situation reminds her of the relationship she has with her own father, Joey leaves all the money hidden in Grace's backpack.

text: At the end of the season she returns to Capeside, and Dawson confesses to her that he wants to be with her. She rejects him saying that all those feelings were in the past, but in the last episode she rushes to the airport, to declare her true feelings for Dawson. She catches him, and they kiss. Joey tells Dawson to go to Los Angeles as that is his destiny, and that they'll meet up after the summer. As she goes to get a refund, she is offered the chance to go to Paris, and the audience is left hanging.

text: Season 6[edit]

text: In the beginning of the sixth season, it is revealed that Joey didn't end up going to Paris, but went home to Capeside. After not talking all summer, she and Dawson meet up and have a one-night stand in her dorm room. The next day it is revealed that Dawson has a girlfriend in California. Joey breaks things off with him. She takes a job as a waitress at Hell's Kitchen, with the help of aspiring drummer, Emma Jones. Joey eventually falls for the bartender, Eddie Doling (Oliver Hudson). They both have a love for writing and literature, but it turns out that he is not officially a student at Worthington, as his family was too poor to afford the tuition.

text: After Christmas, Eddie disappears without telling Joey, going back to Worcester to live with his parents. In trying to find him, Joey gets some help from Harley Hetson—the 15-year-old, alienated, headstrong daughter of her snobbish and somewhat misogynist English professor, Greg Hetson (Roger Howarth), whom Joey clashes with several times during the entire season. Harley lies, telling Eddie that Joey was pregnant with his child in order to lure him back to Boston.

text: Joey and Pacey begin to rekindle their romance after sharing a kiss at his apartment. After being locked overnight in a K-Mart together, they discuss their past and current relationship. Each admits that they miss the other. They briefly reunite, but when Eddie reappears in Joey's life, she breaks it off with Pacey (ironically Pacey and Joey break up at another high school dance resembling the prom).

text: After Pacey and Dawson have another falling out after Pacey's stocks tank and Dawson loses his entire investment, Joey decides that it's time they worked things out for themselves without her in the middle because it "is not her fight" and that it never has been, and never will be. After a heart to heart with Pacey on the dock, Joey brings everyone together to help Dawson make his movie. Joey finally goes to Paris and the final episode of the season ends with her standing before the famous Eiffel Tower.

text: Series finale[edit]

text: The final two episodes are set approximately five years after the season finale. Joey is a junior editor living in New York with her writer boyfriend, Christopher (Jeremy Sisto). During this double episode, the five friends return to Capeside for Gail Leery's third wedding (but second husband). Although she had originally planned to spend the weekend with Christopher, Joey runs scared after finding an engagement ring hidden in the couple's dresser while she is packing for the trip.

text: The five friends reunite at Pacey's restaurant to reminisce about the past. Afterwards, Joey drops by Dawson's house, and the two reestablish their friendship. During Gail's wedding reception, Joey and Pacey kiss (reigniting lingering feelings between the two), but the moment is interrupted when Jen collapses. It is later discovered that Jen has a deadly heart condition.

text: At the same time, Joey ends her relationship with Christopher and chooses between Dawson and Pacey. Though she loves Dawson, she acknowledges that he is her soulmate who is tied to her childhood, a love that is pure and eternally innocent. She also cannot deny she is still in love with Pacey. After Jen's death, she decides to stop running and confront her feelings for Pacey.

text: In the midst of their romantic entanglements, Joey, Dawson, Jack, and Pacey are brought together at the Ice House, now owned by Pacey, to say goodbye to Jen, who dies from pulmonary congestion.

text: In the epilogue, Joey and Pacey watch Dawson's semi-autobiographical television series The Creek in their apartment before calling up Dawson together, where they discover he is going to meet his hero, Steven Spielberg. They have renewed their romantic relationship, and the series ends with them as a couple living together in New York.

text: Notable relationships[edit]

text:
Anderson Crawford

Fling

Beginning: "Kiss" (1.03)
Broke Up: "Kiss" (1.03)

Reason: They didn't continue because she lied about who she was.

Dawson Leery

Kiss

"Detention" (1.07)

Reason: They were dared to kiss each other despite him being with Jen.

Boyfriend

First Relationship:

Beginning: "Decisions" (1.13)
End: "The Dance" (2.06)
Reason: After Jack kisses her, she gets confused about who she really is and what she wants.

Second Relationship:

Beginning: "A Perfect Wedding" (2.18)
End: "Parental Discretion Advised" (2.22)
Reason: Dawson convinced her to get her father to confess to burning down the ice house and his drug use while she wore a wire.

Third Relationship

Beginning: Coda" (4.23)
End: "High Anxiety" (5.06)
Reason: Dawson shuts Joey out when his dad dies and eventually tells her it made him lose all interest in getting back with her.

Fourth Relationship:

Beginning: "The Kids Are Alright" (6.01)
End: "The Song Remains The Same" (6.02)
Reason: After they sleep together, she finds out he had a girlfriend.

Jack McPhee

Kiss

"Full Moon Rising" (2.05)

Reason: She was still with Dawson.

Boyfriend

Beginning: "The Reluctant Hero" (2.08)
Broke Up: "...That Is The Question" (2.15)

Reason: He finds out after writing a poem that he's gay

A.J. Moller

Boyfriend

Beginning: "Northern Lights" (3.13)
Broke Up: "Cinderella Story" (3.17)

Reason: Didn't continue to be a couple because she finds out his best friend loves him and he loves her but doesn't know it yet.

Pacey Witter

Kissed
"Double Date" (1.10)

Reason: She didn't feel the same way and he knew that she liked Dawson and Dawson liked her even though he was still hung up on Jen.

Kissed
"Cinderella Story" (3.17)
"Neverland" (3.18)

Reason: She didn't fully realize that she liked him yet.

Boyfriend

First Relationship:

Beginning: "Stolen Kisses" (3.19)
End: "The Longest Day" (3.20)
Reason: She feels guilty when Dawson finds out about their relationship and ends things with him

Second Relationship:

Beginning: "True Love" (3.23)
End: "Promicide" (4.20)
Reason: They realize that they are different and it seemed like she had a bright future ahead of her while he felt like he was being left behind.

Third Relationship:

Beginning: Castaways" (6.15)
End: "Love Bites" (6.18)
Reason: Eddie comes back.

Fourth Relationship:

Beginning: ...Must Come To An End" (6.24)
Note: Jen tells Joey her final wish is for Joey to choose between Dawson and Pacey. She chooses Pacey.

Drue Valentine

Kissed

Beginning: "The Tao of Dawson" (4.11)
End: "The Tao of Dawson" (4.11)

note: they got locked in a storage locker together, he caught her when she fell and kissed her. She pushed him away immediately, and punched him. She was in a relationship with Pacey.

Charlie Todd

Kissed

Beginning: "Something wild" (5.11)
Broke Up: "Something wild" (5.11)

Reason: Because he cheated on Jen.

Fling

Beginning: "100 Light Years From Home" (5.19)
Broke Up: "Separate Ways (Worlds Apart)" (5.20)

Reason: She tells him to go off and fulfill his dream of being a musician

Elliot

Almost Fling but never kissed

Beginning: "Sleeping Arrangements" (5.12)
Broke Up: "Guerrilla Filmmaking" (5.14)

Reason: She met him when she wasn't over Dawson. Then she thought he slept with Audrey, and after finding out he never slept with her, she gives him another second chance. But she later bails on a date with him (by claiming she was sick) to go to a thing with Wilder who she later kissed and the next day tells him she can't go out with him off-screen.

Professor David Wilder

Kissed/Almost Fling

Beginning: "Something Wilder" (5.13)
Broke Up: "In A Lonely Place" (5.16)

Reason: Joey inadvertently stands David up after getting mugged. This gives him the time to reflect upon the relationship and he realizes that he can't have an affair with a student.

Eddie Doling

First Kiss:

"Instant Karma!" (6.04)

Eddie thinks she only kissed him to get back at Dawson; so it doesn't lead to anything until later episodes.

Boyfriend

First Relationship:
Beginning: "Ego Tripping At The Gates Of Hell" (6.07)
Broke Up: "Rock Bottom" (6.13)

Reason: He left without telling her

Second Relationship:
Beginning: "Love Bites" (6.18)
Broke Up: "Catch-22" (6.20)

Reason: They didn't see a future with each other

Christopher

Boyfriend

Beginning: About a year or two before "All Good Things..." (6.23)
End: "...Must Come To An End" (6.24)

Reason: Joey breaks up with him over the phone after having found a ring in his drawer back in New York.

text: Holmes' thoughts on Joey Potter[edit]

text: "I'm a lot like Joey," said Holmes. "I think they saw that. I come from a small town. I was a tomboy. Joey tries to be articulate and deny that she doesn't have a lot of experience in life. Her life parallels mine, which is all about new everything—relationships, personal perceptions—and about being guarded." Holmes filmed the pilot of Dawson's Creek in Wilmington, North Carolina, during spring break of her senior year of high school in 1997.[2] When the show was picked up by The WB, Holmes moved to Wilmington, where the show filmed.[citation needed]

text: Dawson's Creek ran from 1998 to 2003, and Holmes was the only actor to appear in all 128 episodes. "It was very difficult for me to leave Wilmington, to have my little glass bubble burst and move on. I hate change. On the other hand it was refreshing to play someone else," she said in 2004.[3] Holmes confirmed that, as often happens on soaps, the character was a caricature of the actor:

text:
“
I miss her spirit, and her spunk, and I miss her anxiety. She always had these long speeches about her fears and her future and love. It was a great tool for me personally because I got to get it all out. I was able to psychoanalyze all of it everyday [sic?] with her and then I wouldn't have to do it on my own. So much of me is in Joey and it really felt like I grew up on television.[4]
”

text: Reception[edit]

text: "Joey Potter is a headstrong, vibrant, wily, sultry, and determined go-getter. And yet, in a gloriously contradictory manner, in spite of her tough-as-nails exterior demeanor, Joey's also a frail, sometimes uncertain, emotionally sensitive, in-need-of-love person", said the show's official book.[5] Joey, named for Jo in Little Women, for years had been climbing in Dawson's bedroom window and platonically sharing his bed. Joey's mother had died from cancer when Joey was thirteen and her father, Mike (Gareth Williams), was in prison for "conspiracy to traffic in marijuana in excess of 10,000 pounds." Her harried, unmarried, and very pregnant sister, Bessie (Nina Repeta), about ten years older than Joey,[n 1] was raising her while running the Ice House restaurant, where Joey worked as a waitress. GQ described Joey as "kind of an uptight fussbudget—one who's always twisted up over doing the right thing and bungling-up ways to hook up with her crush and across the creek neighbor, Dawson."[6]

text: The 5 ft 9 in (1.75 m) tall[6][7] brunette enchanted the press, writers of both sexes commenting how Holmes was the sort of girl one wants to bring home to meet the parents and to marry.[8][6] "The Audrey Hepburn of her generation", was one typical comment.[9] Time called her "impossibly lovely" and Entertainment Weekly said she was "next up for idolhood."[10][11] Variety, reviewing the pilot, said Holmes "is a confident young performer who delivers her lines with slyness and conviction."[12] Holmes made such an impression in Hollywood, The New York Times Magazine claimed everyone was seeking to cast a "Katie Holmes type", who, the reporter claimed, "is a throwback to the 1950s: she is a smart girl next door (as opposed to the babe-o-rama blondes)"—the sort represented by her Dawson's Creek co-star Michelle Williams.[13] But her "type" was no less attractive, Arena magazine declaring her "the most coquettishly sexy woman on television. Anywhere."[14]

text: Holmes was soon on the covers of magazines such as Seventeen, TV Guide, and Rolling Stone. Jancee Dunn, an editor at Rolling Stone said she was chosen for the cover because "every time you mention Dawson's Creek you tend to get a lot of dolphin-like shrieks from teenage girls. The fact that she is drop-dead gorgeous didn't hurt either."[15]

text: Reviews were mixed. The Blade said the characters "just talk like they came from a planet ruled by Manhattan psychologists, one where small talk is punishable by death."[16] Holmes herself needed help with the dialogue. "Sometimes before we read a script, I have to get my dictionary and call people to make sure I'm pronouncing some of the words correctly."[17] The show brought her national attention and many fans back home; Toledo's Thanksgiving Day parade in November 1998 had record attendance when Holmes was named grand marshal.[18][19]

text: "As Joey", said Life magazine, "Holmes has had seismic influences on teen life... Through it all, Joey has managed to hang on to her integrity... The show—and Katie's character in particular—has touched a nerve."[20]

text: Her relationship with Pacey was included in TV Guide's list of "The Best TV Couples of All Time".[21] Flavorwire chose the show's other central pairing, Joey and Dawson, in its list of "TV's Best '90s Teen Power Couples".[22]

text: Notes[edit]

text: Jump up ^ Dawson's Creek, Season 2, confirmed Bessie was in high school when Joey was in kindergarten


document_title: Gene

question_text: where do an organism’s genes come from

question_tokens: where do an organism 's genes come from

text: Gene

text: History[edit]

text: Discovery of discrete inherited units[edit]

text: The existence of discrete inheritable units was first suggested by Gregor Mendel (1822–1884).[5] From 1857 to 1864, in Brno (Czech Republic), he studied inheritance patterns in 8000 common edible pea plants, tracking distinct traits from parent to offspring. He described these mathematically as 2n combinations where n is the number of differing characteristics in the original peas. Although he did not use the term gene, he explained his results in terms of discrete inherited units that give rise to observable physical characteristics. This description prefigured Wilhelm Johannsen's distinction between genotype (the genetic material of an organism) and phenotype (the visible traits of that organism). Mendel was also the first to demonstrate independent assortment, the distinction between dominant and recessive traits, the distinction between a heterozygote and homozygote, and the phenomenon of discontinuous inheritance.

text: Prior to Mendel's work, the dominant theory of heredity was one of blending inheritance, which suggested that each parent contributed fluids to the fertilisation process and that the traits of the parents blended and mixed to produce the offspring. Charles Darwin developed a theory of inheritance he termed pangenesis, from Greek pan ("all, whole") and genesis ("birth") / genos ("origin").[6][7] Darwin used the term gemmule to describe hypothetical particles that would mix during reproduction.

text: Mendel's work went largely unnoticed after its first publication in 1866, but was rediscovered in the late 19th century by Hugo de Vries, Carl Correns, and Erich von Tschermak, who (claimed to have) reached similar conclusions in their own research.[8] Specifically, in 1889, Hugo de Vries published his book Intracellular Pangenesis,[9] in which he postulated that different characters have individual hereditary carriers and that inheritance of specific traits in organisms comes in particles. De Vries called these units "pangenes" (Pangens in German), after Darwin's 1868 pangenesis theory.

text: Sixteen years later, in 1905, Wilhelm Johannsen introduced the term 'gene'[4] and William Bateson that of 'genetics'[10] while Eduard Strasburger, amongst others, still used the term 'pangene' for the fundamental physical and functional unit of heredity.[11]

text: Discovery of DNA[edit]

text: Advances in understanding genes and inheritance continued throughout the 20th century. Deoxyribonucleic acid (DNA) was shown to be the molecular repository of genetic information by experiments in the 1940s to 1950s.[12][13] The structure of DNA was studied by Rosalind Franklin and Maurice Wilkins using X-ray crystallography, which led James D. Watson and Francis Crick to publish a model of the double-stranded DNA molecule whose paired nucleotide bases indicated a compelling hypothesis for the mechanism of genetic replication.[14][15]

text: In the early 1950s the prevailing view was that the genes in a chromosome acted like discrete entities, indivisible by recombination and arranged like beads on a string. The experiments of Benzer using mutants defective in the rII region of bacteriophage T4 (1955-1959) showed that individual genes have a simple linear structure and are likely to be equivalent to a linear section of DNA.[16][17]

text: Collectively, this body of research established the central dogma of molecular biology, which states that proteins are translated from RNA, which is transcribed from DNA. This dogma has since been shown to have exceptions, such as reverse transcription in retroviruses. The modern study of genetics at the level of DNA is known as molecular genetics.

text: In 1972, Walter Fiers and his team at the University of Ghent were the first to determine the sequence of a gene: the gene for Bacteriophage MS2 coat protein.[18] The subsequent development of chain-termination DNA sequencing in 1977 by Frederick Sanger improved the efficiency of sequencing and turned it into a routine laboratory tool.[19] An automated version of the Sanger method was used in early phases of the Human Genome Project.[20]

text: Modern synthesis and its successors[edit]

text: The theories developed in the early 20th century to integrate Mendelian genetics with Darwinian evolution are called the modern synthesis, a term introduced by Julian Huxley.[21]

text: Evolutionary biologists have subsequently modified this concept, such as George C. Williams' gene-centric view of evolution. He proposed an evolutionary concept of the gene as a unit of natural selection with the definition: "that which segregates and recombines with appreciable frequency."[22]:24 In this view, the molecular gene transcribes as a unit, and the evolutionary gene inherits as a unit. Related ideas emphasizing the centrality of genes in evolution were popularized by Richard Dawkins.[23][24]

text: Molecular basis[edit]

text: DNA[edit]

text: The vast majority of living organisms encode their genes in long strands of DNA (deoxyribonucleic acid). DNA consists of a chain made from four types of nucleotide subunits, each composed of: a five-carbon sugar (2'-deoxyribose), a phosphate group, and one of the four bases adenine, cytosine, guanine, and thymine.[25]:2.1

text: Two chains of DNA twist around each other to form a DNA double helix with the phosphate-sugar backbone spiralling around the outside, and the bases pointing inwards with adenine base pairing to thymine and guanine to cytosine. The specificity of base pairing occurs because adenine and thymine align to form two hydrogen bonds, whereas cytosine and guanine form three hydrogen bonds. The two strands in a double helix must therefore be complementary, with their sequence of bases matching such that the adenines of one strand are paired with the thymines of the other strand, and so on.[25]:4.1

text: Due to the chemical composition of the pentose residues of the bases, DNA strands have directionality. One end of a DNA polymer contains an exposed hydroxyl group on the deoxyribose; this is known as the 3' end of the molecule. The other end contains an exposed phosphate group; this is the 5' end. The two strands of a double-helix run in opposite directions. Nucleic acid synthesis, including DNA replication and transcription occurs in the 5'→3' direction, because new nucleotides are added via a dehydration reaction that uses the exposed 3' hydroxyl as a nucleophile.[26]:27.2

text: The expression of genes encoded in DNA begins by transcribing the gene into RNA, a second type of nucleic acid that is very similar to DNA, but whose monomers contain the sugar ribose rather than deoxyribose. RNA also contains the base uracil in place of thymine. RNA molecules are less stable than DNA and are typically single-stranded. Genes that encode proteins are composed of a series of three-nucleotide sequences called codons, which serve as the "words" in the genetic "language". The genetic code specifies the correspondence during protein translation between codons and amino acids. The genetic code is nearly the same for all known organisms.[25]:4.1

text: Chromosomes[edit]

text: The total complement of genes in an organism or cell is known as its genome, which may be stored on one or more chromosomes. A chromosome consists of a single, very long DNA helix on which thousands of genes are encoded.[25]:4.2 The region of the chromosome at which a particular gene is located is called its locus. Each locus contains one allele of a gene; however, members of a population may have different alleles at the locus, each with a slightly different gene sequence.

text: The majority of eukaryotic genes are stored on a set of large, linear chromosomes. The chromosomes are packed within the nucleus in complex with storage proteins called histones to form a unit called a nucleosome. DNA packaged and condensed in this way is called chromatin.[25]:4.2 The manner in which DNA is stored on the histones, as well as chemical modifications of the histone itself, regulate whether a particular region of DNA is accessible for gene expression. In addition to genes, eukaryotic chromosomes contain sequences involved in ensuring that the DNA is copied without degradation of end regions and sorted into daughter cells during cell division: replication origins, telomeres and the centromere.[25]:4.2 Replication origins are the sequence regions where DNA replication is initiated to make two copies of the chromosome. Telomeres are long stretches of repetitive sequence that cap the ends of the linear chromosomes and prevent degradation of coding and regulatory regions during DNA replication. The length of the telomeres decreases each time the genome is replicated and has been implicated in the aging process.[28] The centromere is required for binding spindle fibres to separate sister chromatids into daughter cells during cell division.[25]:18.2

text: Prokaryotes (bacteria and archaea) typically store their genomes on a single large, circular chromosome. Similarly, some eukaryotic organelles contain a remnant circular chromosome with a small number of genes.[25]:14.4 Prokaryotes sometimes supplement their chromosome with additional small circles of DNA called plasmids, which usually encode only a few genes and are transferable between individuals. For example, the genes for antibiotic resistance are usually encoded on bacterial plasmids and can be passed between individual cells, even those of different species, via horizontal gene transfer.[29]

text: Whereas the chromosomes of prokaryotes are relatively gene-dense, those of eukaryotes often contain regions of DNA that serve no obvious function. Simple single-celled eukaryotes have relatively small amounts of such DNA, whereas the genomes of complex multicellular organisms, including humans, contain an absolute majority of DNA without an identified function.[30] This DNA has often been referred to as "junk DNA". However, more recent analyses suggest that, although protein-coding DNA makes up barely 2% of the human genome, about 80% of the bases in the genome may be expressed, so the term "junk DNA" may be a misnomer.[3]

text: Structure and function[edit]

text: Structure[edit]

text:
Regulatory sequence
Regulatory sequence
Enhancer
/silencer
Promoter
5'UTR
Open reading frame
3'UTR
Enhancer
/silencer
Proximal
Core
Start
Stop
Terminator
Transcription
DNA
Exon
Exon
Exon
Intron
Intron
Post-transcriptional
modification
Pre-
mRNA
Protein coding region
5'cap
Poly-A tail
Translation
Mature
mRNA
Protein

The structure of a eukaryotic protein-coding gene. Regulatory sequence controls when and where expression occurs for the protein coding region (red). Promoter and enhancer regions (yellow) regulate the transcription of the gene into a pre-mRNA which is modified to remove introns (light grey) and add a 5' cap and poly-A tail (dark grey). The mRNA 5' and 3' untranslated regions (blue) regulate translation into the final protein product.[31]

Polycistronic operon
Regulatory sequence
Regulatory sequence
Enhancer
Enhancer
/silencer
/silencer
Operator
Promoter
5'UTR
ORF
ORF
UTR
3'UTR
Start
Start
Stop
Stop
Terminator
Transcription
DNA
RBS
RBS
Protein coding region
Protein coding region
mRNA
Translation
Protein

The structure of a prokaryotic operon of protein-coding genes. Regulatory sequence controls when expression occurs for the multiple protein coding regions (red). Promoter, operator and enhancer regions (yellow) regulate the transcription of the gene into an mRNA. The mRNA untranslated regions (blue) regulate translation into the final protein products.[31]

text: The structure of a gene consists of many elements of which the actual protein coding sequence is often only a small part. These include DNA regions that are not transcribed as well as untranslated regions of the RNA.

text: Flanking the open reading frame, genes contain a regulatory sequence that is required for their expression. First, genes require a promoter sequence. The promoter is recognized and bound by transcription factors and RNA polymerase to initiate transcription.[25]:7.1 The recognition typically occurs as a consensus sequence like the TATA box. A gene can have more than one promoter, resulting in messenger RNAs (mRNA) that differ in how far they extend in the 5' end.[32] Highly transcribed genes have "strong" promoter sequences that form strong associations with transcription factors, thereby initiating transcription at a high rate. Others genes have "weak" promoters that form weak associations with transcription factors and initiate transcription less frequently.[25]:7.2 Eukaryotic promoter regions are much more complex and difficult to identify than prokaryotic promoters.[25]:7.3

text: Additionally, genes can have regulatory regions many kilobases upstream or downstream of the open reading frame that alter expression. These act by binding to transcription factors which then cause the DNA to loop so that the regulatory sequence (and bound transcription factor) become close to the RNA polymerase binding site.[33] For example, enhancers increase transcription by binding an activator protein which then helps to recruit the RNA polymerase to the promoter; conversely silencers bind repressor proteins and make the DNA less available for RNA polymerase.[34]

text: The transcribed pre-mRNA contains untranslated regions at both ends which contain a ribosome binding site, terminator and start and stop codons.[35] In addition, most eukaryotic open reading frames contain untranslated introns which are removed before the exons are translated. The sequences at the ends of the introns, dictate the splice sites to generate the final mature mRNA which encodes the protein or RNA product.[36]

text: Many prokaryotic genes are organized into operons, with multiple protein-coding sequences that are transcribed as a unit.[37][38] The genes in an operon are transcribed as a continuous messenger RNA, referred to as a polycistronic mRNA. The term cistron in this context is equivalent to gene. The transcription of an operon’s mRNA is often controlled by a repressor that can occur in an active or inactive state depending on the presence of certain specific metabolites.[39] When active, the repressor binds to a DNA sequence at the beginning of the operon, called the operator region, and represses transcription of the operon; when the repressor is inactive transcription of the operon can occur (see e.g. Lac operon). The products of operon genes typically have related functions and are involved in the same regulatory network.[25]:7.3

text: Functional definitions[edit]

text: Defining exactly what section of a DNA sequence comprises a gene is difficult.[1] Regulatory regions of a gene such as enhancers do not necessarily have to be close to the coding sequence on the linear molecule because the intervening DNA can be looped out to bring the gene and its regulatory region into proximity. Similarly, a gene's introns can be much larger than its exons. Regulatory regions can even be on entirely different chromosomes and operate in trans to allow regulatory regions on one chromosome to come in contact with target genes on another chromosome.[40][41]

text: Early work in molecular genetics suggested the concept that one gene makes one protein. This concept (originally called the one gene-one enzyme hypothesis) emerged from an influential 1941 paper by George Beadle and Edward Tatum on experiments with mutants of the fungus Neurospora crassa.[42] Norman Horowitz, an early colleague on the Neurospora research, reminisced in 2004 that “these experiments founded the science of what Beadle and Tatum called biochemical genetics. In actuality they proved to be the opening gun in what became molecular genetics and all the developments that have followed from that.”[43] The one gene-one protein concept has been refined since the discovery of genes that can encode multiple proteins by alternative splicing and coding sequences split in short section across the genome whose mRNAs are concatenated by trans-splicing.[3][44][45]

text: A broad operational definition is sometimes used to encompass the complexity of these diverse phenomena, where a gene is defined as a union of genomic sequences encoding a coherent set of potentially overlapping functional products.[10] This definition categorizes genes by their functional products (proteins or RNA) rather than their specific DNA loci, with regulatory elements classified as gene-associated regions.[10]

text: Gene expression[edit]

text: In all organisms, two steps are required to read the information encoded in a gene's DNA and produce the protein it specifies. First, the gene's DNA is transcribed to messenger RNA (mRNA).[25]:6.1 Second, that mRNA is translated to protein.[25]:6.2 RNA-coding genes must still go through the first step, but are not translated into protein.[46] The process of producing a biologically functional molecule of either RNA or protein is called gene expression, and the resulting molecule is called a gene product.

text: Genetic code[edit]

text: The nucleotide sequence of a gene's DNA specifies the amino acid sequence of a protein through the genetic code. Sets of three nucleotides, known as codons, each correspond to a specific amino acid.[25]:6 The principle that three sequential bases of DNA code for each amino acid was demonstrated in 1961 using frameshift mutations in the rIIB gene of bacteriophage T4[47] (see Crick, Brenner et al. experiment).

text: Additionally, a "start codon", and three "stop codons" indicate the beginning and end of the protein coding region. There are 64 possible codons (four possible nucleotides at each of three positions, hence 43 possible codons) and only 20 standard amino acids; hence the code is redundant and multiple codons can specify the same amino acid. The correspondence between codons and amino acids is nearly universal among all known living organisms.[48]

text: Transcription[edit]

text: Transcription produces a single-stranded RNA molecule known as messenger RNA, whose nucleotide sequence is complementary to the DNA from which it was transcribed.[25]:6.1 The mRNA acts as an intermediate between the DNA gene and its final protein product. The gene's DNA is used as a template to generate a complementary mRNA. The mRNA matches the sequence of the gene's DNA coding strand because it is synthesised as the complement of the template strand. Transcription is performed by an enzyme called an RNA polymerase, which reads the template strand in the 3' to 5' direction and synthesizes the RNA from 5' to 3'. To initiate transcription, the polymerase first recognizes and binds a promoter region of the gene. Thus, a major mechanism of gene regulation is the blocking or sequestering the promoter region, either by tight binding by repressor molecules that physically block the polymerase, or by organizing the DNA so that the promoter region is not accessible.[25]:7

text: In prokaryotes, transcription occurs in the cytoplasm; for very long transcripts, translation may begin at the 5' end of the RNA while the 3' end is still being transcribed. In eukaryotes, transcription occurs in the nucleus, where the cell's DNA is stored. The RNA molecule produced by the polymerase is known as the primary transcript and undergoes post-transcriptional modifications before being exported to the cytoplasm for translation. One of the modifications performed is the splicing of introns which are sequences in the transcribed region that do not encode protein. Alternative splicing mechanisms can result in mature transcripts from the same gene having different sequences and thus coding for different proteins. This is a major form of regulation in eukaryotic cells and also occurs in some prokaryotes.[25]:7.5[49]

text: Translation[edit]

text: Translation is the process by which a mature mRNA molecule is used as a template for synthesizing a new protein.[25]:6.2 Translation is carried out by ribosomes, large complexes of RNA and protein responsible for carrying out the chemical reactions to add new amino acids to a growing polypeptide chain by the formation of peptide bonds. The genetic code is read three nucleotides at a time, in units called codons, via interactions with specialized RNA molecules called transfer RNA (tRNA). Each tRNA has three unpaired bases known as the anticodon that are complementary to the codon it reads on the mRNA. The tRNA is also covalently attached to the amino acid specified by the complementary codon. When the tRNA binds to its complementary codon in an mRNA strand, the ribosome attaches its amino acid cargo to the new polypeptide chain, which is synthesized from amino terminus to carboxyl terminus. During and after synthesis, most new proteins must fold to their active three-dimensional structure before they can carry out their cellular functions.[25]:3

text: Regulation[edit]

text: Genes are regulated so that they are expressed only when the product is needed, since expression draws on limited resources.[25]:7 A cell regulates its gene expression depending on its external environment (e.g. available nutrients, temperature and other stresses), its internal environment (e.g. cell division cycle, metabolism, infection status), and its specific role if in a multicellular organism. Gene expression can be regulated at any step: from transcriptional initiation, to RNA processing, to post-translational modification of the protein. The regulation of lactose metabolism genes in E. coli (lac operon) was the first such mechanism to be described in 1961.[50]

text: RNA genes[edit]

text: A typical protein-coding gene is first copied into RNA as an intermediate in the manufacture of the final protein product.[25]:6.1 In other cases, the RNA molecules are the actual functional products, as in the synthesis of ribosomal RNA and transfer RNA. Some RNAs known as ribozymes are capable of enzymatic function, and microRNA has a regulatory role. The DNA sequences from which such RNAs are transcribed are known as non-coding RNA genes.[46]

text: Some viruses store their entire genomes in the form of RNA, and contain no DNA at all.[51][52] Because they use RNA to store genes, their cellular hosts may synthesize their proteins as soon as they are infected and without the delay in waiting for transcription.[53] On the other hand, RNA retroviruses, such as HIV, require the reverse transcription of their genome from RNA into DNA before their proteins can be synthesized. RNA-mediated epigenetic inheritance has also been observed in plants and very rarely in animals.[54]

text: Inheritance[edit]

text: Organisms inherit their genes from their parents. Asexual organisms simply inherit a complete copy of their parent's genome. Sexual organisms have two copies of each chromosome because they inherit one complete set from each parent.[25]:1

text: Mendelian inheritance[edit]

text: According to Mendelian inheritance, variations in an organism's phenotype (observable physical and behavioral characteristics) are due in part to variations in its genotype (particular set of genes). Each gene specifies a particular trait with different sequence of a gene (alleles) giving rise to different phenotypes. Most eukaryotic organisms (such as the pea plants Mendel worked on) have two alleles for each trait, one inherited from each parent.[25]:20

text: Alleles at a locus may be dominant or recessive; dominant alleles give rise to their corresponding phenotypes when paired with any other allele for the same trait, whereas recessive alleles give rise to their corresponding phenotype only when paired with another copy of the same allele. If you know the genotypes of the organisms, you can determine which alleles are dominant and which are recessive. For example, if the allele specifying tall stems in pea plants is dominant over the allele specifying short stems, then pea plants that inherit one tall allele from one parent and one short allele from the other parent will also have tall stems. Mendel's work demonstrated that alleles assort independently in the production of gametes, or germ cells, ensuring variation in the next generation. Although Mendelian inheritance remains a good model for many traits determined by single genes (including a number of well-known genetic disorders) it does not include the physical processes of DNA replication and cell division.[55][56]

text: DNA replication and cell division[edit]

text: The growth, development, and reproduction of organisms relies on cell division; the process by which a single cell divides into two usually identical daughter cells. This requires first making a duplicate copy of every gene in the genome in a process called DNA replication.[25]:5.2 The copies are made by specialized enzymes known as DNA polymerases, which "read" one strand of the double-helical DNA, known as the template strand, and synthesize a new complementary strand. Because the DNA double helix is held together by base pairing, the sequence of one strand completely specifies the sequence of its complement; hence only one strand needs to be read by the enzyme to produce a faithful copy. The process of DNA replication is semiconservative; that is, the copy of the genome inherited by each daughter cell contains one original and one newly synthesized strand of DNA.[25]:5.2

text: The rate of DNA replication in living cells was first measured as the rate of phage T4 DNA elongation in phage-infected E. coli and found to be impressively rapid.[57] During the period of exponential DNA increase at 37 °C, the rate of elongation was 749 nucleotides per second.

text: After DNA replication is complete, the cell must physically separate the two copies of the genome and divide into two distinct membrane-bound cells.[25]:18.2 In prokaryotes (bacteria and archaea) this usually occurs via a relatively simple process called binary fission, in which each circular genome attaches to the cell membrane and is separated into the daughter cells as the membrane invaginates to split the cytoplasm into two membrane-bound portions. Binary fission is extremely fast compared to the rates of cell division in eukaryotes. Eukaryotic cell division is a more complex process known as the cell cycle; DNA replication occurs during a phase of this cycle known as S phase, whereas the process of segregating chromosomes and splitting the cytoplasm occurs during M phase.[25]:18.1

text: Molecular inheritance[edit]

text: The duplication and transmission of genetic material from one generation of cells to the next is the basis for molecular inheritance, and the link between the classical and molecular pictures of genes. Organisms inherit the characteristics of their parents because the cells of the offspring contain copies of the genes in their parents' cells. In asexually reproducing organisms, the offspring will be a genetic copy or clone of the parent organism. In sexually reproducing organisms, a specialized form of cell division called meiosis produces cells called gametes or germ cells that are haploid, or contain only one copy of each gene.[25]:20.2 The gametes produced by females are called eggs or ova, and those produced by males are called sperm. Two gametes fuse to form a diploid fertilized egg, a single cell that has two sets of genes, with one copy of each gene from the mother and one from the father.[25]:20

text: During the process of meiotic cell division, an event called genetic recombination or crossing-over can sometimes occur, in which a length of DNA on one chromatid is swapped with a length of DNA on the corresponding homologous non-sister chromatid. This can result in reassortment of otherwise linked alleles.[25]:5.5 The Mendelian principle of independent assortment asserts that each of a parent's two genes for each trait will sort independently into gametes; which allele an organism inherits for one trait is unrelated to which allele it inherits for another trait. This is in fact only true for genes that do not reside on the same chromosome, or are located very far from one another on the same chromosome. The closer two genes lie on the same chromosome, the more closely they will be associated in gametes and the more often they will appear together; genes that are very close are essentially never separated because it is extremely unlikely that a crossover point will occur between them. This is known as genetic linkage.[58]

text: Molecular evolution[edit]

text: Mutation[edit]

text: DNA replication is for the most part extremely accurate, however errors (mutations) do occur.[25]:7.6 The error rate in eukaryotic cells can be as low as 10−8 per nucleotide per replication,[59][60] whereas for some RNA viruses it can be as high as 10−3.[61] This means that each generation, each human genome accumulates 1–2 new mutations.[61] Small mutations can be caused by DNA replication and the aftermath of DNA damage and include point mutations in which a single base is altered and frameshift mutations in which a single base is inserted or deleted. Either of these mutations can change the gene by missense (change a codon to encode a different amino acid) or nonsense (a premature stop codon).[62] Larger mutations can be caused by errors in recombination to cause chromosomal abnormalities including the duplication, deletion, rearrangement or inversion of large sections of a chromosome. Additionally, DNA repair mechanisms can introduce mutational errors when repairing physical damage to the molecule. The repair, even with mutation, is more important to survival than restoring an exact copy, for example when repairing double-strand breaks.[25]:5.4

text: When multiple different alleles for a gene are present in a species's population it is called polymorphic. Most different alleles are functionally equivalent, however some alleles can give rise to different phenotypic traits. A gene's most common allele is called the wild type, and rare alleles are called mutants. The genetic variation in relative frequencies of different alleles in a population is due to both natural selection and genetic drift.[63] The wild-type allele is not necessarily the ancestor of less common alleles, nor is it necessarily fitter.

text: Most mutations within genes are neutral, having no effect on the organism's phenotype (silent mutations). Some mutations do not change the amino acid sequence because multiple codons encode the same amino acid (synonymous mutations). Other mutations can be neutral if they lead to amino acid sequence changes, but the protein still functions similarly with the new amino acid (e.g. conservative mutations). Many mutations, however, are deleterious or even lethal, and are removed from populations by natural selection. Genetic disorders are the result of deleterious mutations and can be due to spontaneous mutation in the affected individual, or can be inherited. Finally, a small fraction of mutations are beneficial, improving the organism's fitness and are extremely important for evolution, since their directional selection leads to adaptive evolution.[25]:7.6

text: Sequence homology[edit]

text: Genes with a most recent common ancestor, and thus a shared evolutionary ancestry, are known as homologs.[64] These genes appear either from gene duplication within an organism's genome, where they are known as paralogous genes, or are the result of divergence of the genes after a speciation event, where they are known as orthologous genes,[25]:7.6 and often perform the same or similar functions in related organisms. It is often assumed that the functions of orthologous genes are more similar than those of paralogous genes, although the difference is minimal.[65][66]

text: The relationship between genes can be measured by comparing the sequence alignment of their DNA.[25]:7.6 The degree of sequence similarity between homologous genes is called conserved sequence. Most changes to a gene's sequence do not affect its function and so genes accumulate mutations over time by neutral molecular evolution. Additionally, any selection on a gene will cause its sequence to diverge at a different rate. Genes under stabilizing selection are constrained and so change more slowly whereas genes under directional selection change sequence more rapidly.[67] The sequence differences between genes can be used for phylogenetic analyses to study how those genes have evolved and how the organisms they come from are related.[68][69]

text: Origins of new genes[edit]

text: The most common source of new genes in eukaryotic lineages is gene duplication, which creates copy number variation of an existing gene in the genome.[70][71] The resulting genes (paralogs) may then diverge in sequence and in function. Sets of genes formed in this way compose a gene family. Gene duplications and losses within a family are common and represent a major source of evolutionary biodiversity.[72] Sometimes, gene duplication may result in a nonfunctional copy of a gene, or a functional copy may be subject to mutations that result in loss of function; such nonfunctional genes are called pseudogenes.[25]:7.6

text: "Orphan" genes, whose sequence shows no similarity to existing genes, are less common than gene duplicates. Estimates of the number of genes with no homologs outside humans range from 18[73] to 60.[74] Two primary sources of orphan protein-coding genes are gene duplication followed by extremely rapid sequence change, such that the original relationship is undetectable by sequence comparisons, and de novo conversion of a previously non-coding sequence into a protein-coding gene.[75] De novo genes are typically shorter and simpler in structure than most eukaryotic genes, with few if any introns.[70] Over long evolutionary time periods, de novo gene birth may be responsible for a significant fraction of taxonomically-restricted gene families.[76]

text: Horizontal gene transfer refers to the transfer of genetic material through a mechanism other than reproduction. This mechanism is a common source of new genes in prokaryotes, sometimes thought to contribute more to genetic variation than gene duplication.[77] It is a common means of spreading antibiotic resistance, virulence, and adaptive metabolic functions.[29][78] Although horizontal gene transfer is rare in eukaryotes, likely examples have been identified of protist and alga genomes containing genes of bacterial origin.[79][80]

text: Genome[edit]

text: The genome is the total genetic material of an organism and includes both the genes and non-coding sequences.[81]

text: Number of genes[edit]

text: The genome size, and the number of genes it encodes varies widely between organisms. The smallest genomes occur in viruses (which can have as few as 2 protein-coding genes),[90] and viroids (which act as a single non-coding RNA gene).[91] Conversely, plants can have extremely large genomes,[92] with rice containing >46,000 protein-coding genes.[93] The total number of protein-coding genes (the Earth's proteome) is estimated to be 5 million sequences.[94]

text: Although the number of base-pairs of DNA in the human genome has been known since the 1960s, the estimated number of genes has changed over time as definitions of genes, and methods of detecting them have been refined. Initial theoretical predictions of the number of human genes were as high as 2,000,000.[95] Early experimental measures indicated there to be 50,000–100,000 transcribed genes (expressed sequence tags).[96] Subsequently, the sequencing in the Human Genome Project indicated that many of these transcripts were alternative variants of the same genes, and the total number of protein-coding genes was revised down to ~20,000[89] with 13 genes encoded on the mitochondrial genome.[87] With the GENCODE annotation project, that estimate has continued to fall to 19,000.[97] Of the human genome, only 1–2% consists of protein-coding genes,[98] with the remainder being 'noncoding' DNA such as introns, retrotransposons, and noncoding RNAs.[98][99] Every multicellular organism has all its genes in each cell of its body but not every gene functions in every cell .

text: Essential genes[edit]

text: Essential genes are the set of genes thought to be critical for an organism's survival.[101] This definition assumes the abundant availability of all relevant nutrients and the absence of environmental stress. Only a small portion of an organism's genes are essential. In bacteria, an estimated 250–400 genes are essential for Escherichia coli and Bacillus subtilis, which is less than 10% of their genes.[102][103][104] Half of these genes are orthologs in both organisms and are largely involved in protein synthesis.[104] In the budding yeast Saccharomyces cerevisiae the number of essential genes is slightly higher, at 1000 genes (~20% of their genes).[105] Although the number is more difficult to measure in higher eukaryotes, mice and humans are estimated to have around 2000 essential genes (~10% of their genes).[106] The synthetic organism, Syn 3, has a minimal genome of 473 essential genes and quasi-essential genes (necessary for fast growth), although 149 have unknown function.[100]

text: Essential genes include Housekeeping genes (critical for basic cell functions)[107] as well as genes that are expressed at different times in the organisms development or life cycle.[108] Housekeeping genes are used as experimental controls when analysing gene expression, since they are constitutively expressed at a relatively constant level.

text: Genetic and genomic nomenclature[edit]

text: Gene nomenclature has been established by the HUGO Gene Nomenclature Committee (HGNC) for each known human gene in the form of an approved gene name and symbol (short-form abbreviation), which can be accessed through a database maintained by HGNC. Symbols are chosen to be unique, and each gene has only one symbol (although approved symbols sometimes change). Symbols are preferably kept consistent with other members of a gene family and with homologs in other species, particularly the mouse due to its role as a common model organism.[109]

text: Genetic engineering[edit]

text: Genetic engineering is the modification of an organism's genome through biotechnology. Since the 1970s, a variety of techniques have been developed to specifically add, remove and edit genes in an organism.[110] Recently developed genome engineering techniques use engineered nuclease enzymes to create targeted DNA repair in a chromosome to either disrupt or edit a gene when the break is repaired.[111][112][113][114] The related term synthetic biology is sometimes used to refer to extensive genetic engineering of an organism.[115]

text: Genetic engineering is now a routine research tool with model organisms. For example, genes are easily added to bacteria[116] and lineages of knockout mice with a specific gene's function disrupted are used to investigate that gene's function.[117][118] Many organisms have been genetically modified for applications in agriculture, industrial biotechnology, and medicine.

text: For multicellular organisms, typically the embryo is engineered which grows into the adult genetically modified organism.[119] However, the genomes of cells in an adult organism can be edited using gene therapy techniques to treat genetic diseases.