-Sex (gender) Determination Dr. Thomas Hunt Morgan (1866-1945) -worked with fruit flies (Drosophila...
-
Upload
meredith-potter -
Category
Documents
-
view
231 -
download
2
Transcript of -Sex (gender) Determination Dr. Thomas Hunt Morgan (1866-1945) -worked with fruit flies (Drosophila...
![Page 1: -Sex (gender) Determination Dr. Thomas Hunt Morgan (1866-1945) -worked with fruit flies (Drosophila melanogaster) -pioneer in the use of fruit flies to.](https://reader036.fdocuments.net/reader036/viewer/2022062321/56649f0d5503460f94c21e48/html5/thumbnails/1.jpg)
-Sex (gender) DeterminationDr. Thomas Hunt Morgan (1866-1945) -worked with fruit flies (Drosophila melanogaster)-pioneer in the use of fruit flies to study genetics and heredity
![Page 2: -Sex (gender) Determination Dr. Thomas Hunt Morgan (1866-1945) -worked with fruit flies (Drosophila melanogaster) -pioneer in the use of fruit flies to.](https://reader036.fdocuments.net/reader036/viewer/2022062321/56649f0d5503460f94c21e48/html5/thumbnails/2.jpg)
Normal Fly
White Eyes
Short Wings
Curly Wings Yellow Body Ebony Body
Fruit Fly (Drosophila melanogaster) Phenotypes
![Page 3: -Sex (gender) Determination Dr. Thomas Hunt Morgan (1866-1945) -worked with fruit flies (Drosophila melanogaster) -pioneer in the use of fruit flies to.](https://reader036.fdocuments.net/reader036/viewer/2022062321/56649f0d5503460f94c21e48/html5/thumbnails/3.jpg)
-Early in his work, he viewed karyotypes of fruit fly chromosomes,and noticed that male and female Flies had slightly different chromosomes.
Fruit flies have 4 pairs of chromosomes, so the diploid number is 8.
![Page 4: -Sex (gender) Determination Dr. Thomas Hunt Morgan (1866-1945) -worked with fruit flies (Drosophila melanogaster) -pioneer in the use of fruit flies to.](https://reader036.fdocuments.net/reader036/viewer/2022062321/56649f0d5503460f94c21e48/html5/thumbnails/4.jpg)
The Fruit Fly Karyotype
![Page 5: -Sex (gender) Determination Dr. Thomas Hunt Morgan (1866-1945) -worked with fruit flies (Drosophila melanogaster) -pioneer in the use of fruit flies to.](https://reader036.fdocuments.net/reader036/viewer/2022062321/56649f0d5503460f94c21e48/html5/thumbnails/5.jpg)
3 of the pairs are homologous, and thesame in male and female. The 4th pair is different in male and female.
The 3 pairs that are the same are called autosomal, and are not involved in gender determination.
![Page 6: -Sex (gender) Determination Dr. Thomas Hunt Morgan (1866-1945) -worked with fruit flies (Drosophila melanogaster) -pioneer in the use of fruit flies to.](https://reader036.fdocuments.net/reader036/viewer/2022062321/56649f0d5503460f94c21e48/html5/thumbnails/6.jpg)
Sex-Linked Traits-In 1910, Dr. Morgan found that the trait of white eyes was found mostlyin males (but does happen in females).-He hypothesized that the recessive gene for eye color was on the X chromosome, and that the trait was sex-linked.
![Page 7: -Sex (gender) Determination Dr. Thomas Hunt Morgan (1866-1945) -worked with fruit flies (Drosophila melanogaster) -pioneer in the use of fruit flies to.](https://reader036.fdocuments.net/reader036/viewer/2022062321/56649f0d5503460f94c21e48/html5/thumbnails/7.jpg)
He carried out 2 crosses to test hishypothesis.1) Cross a white-eyed male with a red-eyed female. Result: 1/2 red eyed females 1/2 red eyed males
So what will the genotypes of the parents look like?
![Page 8: -Sex (gender) Determination Dr. Thomas Hunt Morgan (1866-1945) -worked with fruit flies (Drosophila melanogaster) -pioneer in the use of fruit flies to.](https://reader036.fdocuments.net/reader036/viewer/2022062321/56649f0d5503460f94c21e48/html5/thumbnails/8.jpg)
Xr Y
XR
XR
XRXr
XRXr
XRY
XRY
![Page 9: -Sex (gender) Determination Dr. Thomas Hunt Morgan (1866-1945) -worked with fruit flies (Drosophila melanogaster) -pioneer in the use of fruit flies to.](https://reader036.fdocuments.net/reader036/viewer/2022062321/56649f0d5503460f94c21e48/html5/thumbnails/9.jpg)
2) Cross one of the F1 red-eyedfemales with a red-eyed maleResult: 1/2 red-eyed females
1/4 red-eyed males 1/4 white-eyed males
Start with the genotypes of the parents.
![Page 10: -Sex (gender) Determination Dr. Thomas Hunt Morgan (1866-1945) -worked with fruit flies (Drosophila melanogaster) -pioneer in the use of fruit flies to.](https://reader036.fdocuments.net/reader036/viewer/2022062321/56649f0d5503460f94c21e48/html5/thumbnails/10.jpg)
XR Y
XR
Xr
XRXR
XRXr
XRY
XrY
![Page 11: -Sex (gender) Determination Dr. Thomas Hunt Morgan (1866-1945) -worked with fruit flies (Drosophila melanogaster) -pioneer in the use of fruit flies to.](https://reader036.fdocuments.net/reader036/viewer/2022062321/56649f0d5503460f94c21e48/html5/thumbnails/11.jpg)
He predicted that he could produce awhite-eyed female by crossing an F1red-eye female with a white-eye male.
XRXr x XrY
![Page 12: -Sex (gender) Determination Dr. Thomas Hunt Morgan (1866-1945) -worked with fruit flies (Drosophila melanogaster) -pioneer in the use of fruit flies to.](https://reader036.fdocuments.net/reader036/viewer/2022062321/56649f0d5503460f94c21e48/html5/thumbnails/12.jpg)
Xr Y
XR
Xr
XRXr
XrXr
XRY
XrY
![Page 13: -Sex (gender) Determination Dr. Thomas Hunt Morgan (1866-1945) -worked with fruit flies (Drosophila melanogaster) -pioneer in the use of fruit flies to.](https://reader036.fdocuments.net/reader036/viewer/2022062321/56649f0d5503460f94c21e48/html5/thumbnails/13.jpg)
Many sex-linked abnormalities arecaused by a recessive gene on the Xchromosome.
Examples:Red-green color blindnessHemophilia
![Page 14: -Sex (gender) Determination Dr. Thomas Hunt Morgan (1866-1945) -worked with fruit flies (Drosophila melanogaster) -pioneer in the use of fruit flies to.](https://reader036.fdocuments.net/reader036/viewer/2022062321/56649f0d5503460f94c21e48/html5/thumbnails/14.jpg)
![Page 15: -Sex (gender) Determination Dr. Thomas Hunt Morgan (1866-1945) -worked with fruit flies (Drosophila melanogaster) -pioneer in the use of fruit flies to.](https://reader036.fdocuments.net/reader036/viewer/2022062321/56649f0d5503460f94c21e48/html5/thumbnails/15.jpg)
Nondisjunction-failure of chromosomes to segregateduring meiosis, resulting in abnormalchromosome numbers in future generations. -Nondisjunction may happen to anychromosome, autosomal or not.
![Page 16: -Sex (gender) Determination Dr. Thomas Hunt Morgan (1866-1945) -worked with fruit flies (Drosophila melanogaster) -pioneer in the use of fruit flies to.](https://reader036.fdocuments.net/reader036/viewer/2022062321/56649f0d5503460f94c21e48/html5/thumbnails/16.jpg)
Nondisjunction in sex chromosomescan result in many genotypes, such as:
XY (not viable)XXX (“super females”)XXYXXXY (not viable)
![Page 17: -Sex (gender) Determination Dr. Thomas Hunt Morgan (1866-1945) -worked with fruit flies (Drosophila melanogaster) -pioneer in the use of fruit flies to.](https://reader036.fdocuments.net/reader036/viewer/2022062321/56649f0d5503460f94c21e48/html5/thumbnails/17.jpg)
The following diseases are caused by a
nondisjunction of the
chromosomes.
![Page 18: -Sex (gender) Determination Dr. Thomas Hunt Morgan (1866-1945) -worked with fruit flies (Drosophila melanogaster) -pioneer in the use of fruit flies to.](https://reader036.fdocuments.net/reader036/viewer/2022062321/56649f0d5503460f94c21e48/html5/thumbnails/18.jpg)
Down’s Syndrome:-caused by a nondisjunction in the 21st pair of chromosomes.
-symptoms include mental retardation,abnormal facial traits, short arms and legs, many internal defects.
![Page 19: -Sex (gender) Determination Dr. Thomas Hunt Morgan (1866-1945) -worked with fruit flies (Drosophila melanogaster) -pioneer in the use of fruit flies to.](https://reader036.fdocuments.net/reader036/viewer/2022062321/56649f0d5503460f94c21e48/html5/thumbnails/19.jpg)
Downes Syndrome
![Page 20: -Sex (gender) Determination Dr. Thomas Hunt Morgan (1866-1945) -worked with fruit flies (Drosophila melanogaster) -pioneer in the use of fruit flies to.](https://reader036.fdocuments.net/reader036/viewer/2022062321/56649f0d5503460f94c21e48/html5/thumbnails/20.jpg)
Turner Syndrome:-caused by a nondisjunction of sexchromosomes.-X genotype (therefore female)Symptoms: sterile, usually short, below average intelligence, usually fail to develop normal female characteristics.
![Page 21: -Sex (gender) Determination Dr. Thomas Hunt Morgan (1866-1945) -worked with fruit flies (Drosophila melanogaster) -pioneer in the use of fruit flies to.](https://reader036.fdocuments.net/reader036/viewer/2022062321/56649f0d5503460f94c21e48/html5/thumbnails/21.jpg)
Turner Syndrome
![Page 22: -Sex (gender) Determination Dr. Thomas Hunt Morgan (1866-1945) -worked with fruit flies (Drosophila melanogaster) -pioneer in the use of fruit flies to.](https://reader036.fdocuments.net/reader036/viewer/2022062321/56649f0d5503460f94c21e48/html5/thumbnails/22.jpg)
![Page 23: -Sex (gender) Determination Dr. Thomas Hunt Morgan (1866-1945) -worked with fruit flies (Drosophila melanogaster) -pioneer in the use of fruit flies to.](https://reader036.fdocuments.net/reader036/viewer/2022062321/56649f0d5503460f94c21e48/html5/thumbnails/23.jpg)
Klinefelter’s Syndrome
-Individuals have an XXY genotype, so therefore are male.-Sterile, usually fail to develop normal male sex characteristics. -Very long arms and legs-Below average intelligence
![Page 24: -Sex (gender) Determination Dr. Thomas Hunt Morgan (1866-1945) -worked with fruit flies (Drosophila melanogaster) -pioneer in the use of fruit flies to.](https://reader036.fdocuments.net/reader036/viewer/2022062321/56649f0d5503460f94c21e48/html5/thumbnails/24.jpg)
Klinefelter’s Syndrome
![Page 25: -Sex (gender) Determination Dr. Thomas Hunt Morgan (1866-1945) -worked with fruit flies (Drosophila melanogaster) -pioneer in the use of fruit flies to.](https://reader036.fdocuments.net/reader036/viewer/2022062321/56649f0d5503460f94c21e48/html5/thumbnails/25.jpg)
![Page 26: -Sex (gender) Determination Dr. Thomas Hunt Morgan (1866-1945) -worked with fruit flies (Drosophila melanogaster) -pioneer in the use of fruit flies to.](https://reader036.fdocuments.net/reader036/viewer/2022062321/56649f0d5503460f94c21e48/html5/thumbnails/26.jpg)
Affected individuals rarely live past infancy because of the life-threatening medical problems associated with this condition.
-skeletal abnormalities, including polydactyly and syndactyly
-weak muscle tone (hypotonia)
-a cleft lip-an opening in the roof of the mouth (a cleft palate)These abnormalities include: small eyes
-a chromosomal condition that is associated with severe cognitive disability and certain physical abnormalities.
Trisomy 13 (Patau Syndrome)
![Page 27: -Sex (gender) Determination Dr. Thomas Hunt Morgan (1866-1945) -worked with fruit flies (Drosophila melanogaster) -pioneer in the use of fruit flies to.](https://reader036.fdocuments.net/reader036/viewer/2022062321/56649f0d5503460f94c21e48/html5/thumbnails/27.jpg)
Patau Syndrome
![Page 28: -Sex (gender) Determination Dr. Thomas Hunt Morgan (1866-1945) -worked with fruit flies (Drosophila melanogaster) -pioneer in the use of fruit flies to.](https://reader036.fdocuments.net/reader036/viewer/2022062321/56649f0d5503460f94c21e48/html5/thumbnails/28.jpg)
Polydactyly
![Page 30: -Sex (gender) Determination Dr. Thomas Hunt Morgan (1866-1945) -worked with fruit flies (Drosophila melanogaster) -pioneer in the use of fruit flies to.](https://reader036.fdocuments.net/reader036/viewer/2022062321/56649f0d5503460f94c21e48/html5/thumbnails/30.jpg)
Syndactyly
![Page 31: -Sex (gender) Determination Dr. Thomas Hunt Morgan (1866-1945) -worked with fruit flies (Drosophila melanogaster) -pioneer in the use of fruit flies to.](https://reader036.fdocuments.net/reader036/viewer/2022062321/56649f0d5503460f94c21e48/html5/thumbnails/31.jpg)
![Page 32: -Sex (gender) Determination Dr. Thomas Hunt Morgan (1866-1945) -worked with fruit flies (Drosophila melanogaster) -pioneer in the use of fruit flies to.](https://reader036.fdocuments.net/reader036/viewer/2022062321/56649f0d5503460f94c21e48/html5/thumbnails/32.jpg)
Most cases of trisomy 13 result when each cell in the body has three copies of chromosome 13 instead of the usual two copies.
A small percentage of cases occur when only some of the body's cells have an extra copy of chromosome13, resulting in a mixed population of cells with a differing number of chromosomes. Such cases are sometimes called mosaic trisomy 13.
Mosaic trisomy 13 results from a non-disjunctionin a somatic cell during early development.
![Page 33: -Sex (gender) Determination Dr. Thomas Hunt Morgan (1866-1945) -worked with fruit flies (Drosophila melanogaster) -pioneer in the use of fruit flies to.](https://reader036.fdocuments.net/reader036/viewer/2022062321/56649f0d5503460f94c21e48/html5/thumbnails/33.jpg)
A young boy (7) sufferingfrom Patau Syndrome.
He is deaf, and legally blind.
![Page 34: -Sex (gender) Determination Dr. Thomas Hunt Morgan (1866-1945) -worked with fruit flies (Drosophila melanogaster) -pioneer in the use of fruit flies to.](https://reader036.fdocuments.net/reader036/viewer/2022062321/56649f0d5503460f94c21e48/html5/thumbnails/34.jpg)
The following diseases are not caused by a nondisjunction in any chromosomes.
![Page 35: -Sex (gender) Determination Dr. Thomas Hunt Morgan (1866-1945) -worked with fruit flies (Drosophila melanogaster) -pioneer in the use of fruit flies to.](https://reader036.fdocuments.net/reader036/viewer/2022062321/56649f0d5503460f94c21e48/html5/thumbnails/35.jpg)
Tay-Sachs Disease-Affects mostly Jewish people.-caused by a homozygous recessivegene. Symptoms: nervous system does Not develop normally, causes inability to move. Death by age 2 or 3.
![Page 36: -Sex (gender) Determination Dr. Thomas Hunt Morgan (1866-1945) -worked with fruit flies (Drosophila melanogaster) -pioneer in the use of fruit flies to.](https://reader036.fdocuments.net/reader036/viewer/2022062321/56649f0d5503460f94c21e48/html5/thumbnails/36.jpg)
PKU-caused by a homozygous recessive gene.Symptoms: missing enzyme, can lead to severe mental retardation. this condition can be helped with a special diet. (no phenylalanine)NO!- Diet sodas, nutra-sweet
![Page 37: -Sex (gender) Determination Dr. Thomas Hunt Morgan (1866-1945) -worked with fruit flies (Drosophila melanogaster) -pioneer in the use of fruit flies to.](https://reader036.fdocuments.net/reader036/viewer/2022062321/56649f0d5503460f94c21e48/html5/thumbnails/37.jpg)
Huntington’s Disease-due to a dominant gene, thereforea person heterozygous can have the condition. Symptoms: deterioration of the brain,leading to memory loss, and lossof control of movement.
![Page 38: -Sex (gender) Determination Dr. Thomas Hunt Morgan (1866-1945) -worked with fruit flies (Drosophila melanogaster) -pioneer in the use of fruit flies to.](https://reader036.fdocuments.net/reader036/viewer/2022062321/56649f0d5503460f94c21e48/html5/thumbnails/38.jpg)
Cystic Fibrosis-caused by a recessive gene on the 7th chromosome pair.Symptoms: lining of lungs does notproduce fluid, causing particles tobe retained in lungs. Chronic cough,difficulty breathing. Death usuallyby 20 years of age.
![Page 39: -Sex (gender) Determination Dr. Thomas Hunt Morgan (1866-1945) -worked with fruit flies (Drosophila melanogaster) -pioneer in the use of fruit flies to.](https://reader036.fdocuments.net/reader036/viewer/2022062321/56649f0d5503460f94c21e48/html5/thumbnails/39.jpg)
Sickle-Cell Anemia-This disease affects mostly African Americans. -Homozygous recessive disease.-Causes irregular shaped red blood cells,hemoglobin that does not hold oxygen well. -Clotting due to cell shape, anemia due to low affinity of hemoglobin for oxygen.
![Page 40: -Sex (gender) Determination Dr. Thomas Hunt Morgan (1866-1945) -worked with fruit flies (Drosophila melanogaster) -pioneer in the use of fruit flies to.](https://reader036.fdocuments.net/reader036/viewer/2022062321/56649f0d5503460f94c21e48/html5/thumbnails/40.jpg)
In equatorial Africa, where the disease originated, it is actuallybeneficial to have sickle cell, because it protects you from having malaria, which is far more deadly.
![Page 41: -Sex (gender) Determination Dr. Thomas Hunt Morgan (1866-1945) -worked with fruit flies (Drosophila melanogaster) -pioneer in the use of fruit flies to.](https://reader036.fdocuments.net/reader036/viewer/2022062321/56649f0d5503460f94c21e48/html5/thumbnails/41.jpg)
Methods of Disease Detection1) Amniocentesis: Fluid that surrounds the fetus is withdrawn with a needle, and analyzed for chromosome abnormalities
Examples: Downs Syndrome,Turner Syndrome Klinefelter Syndrome
![Page 42: -Sex (gender) Determination Dr. Thomas Hunt Morgan (1866-1945) -worked with fruit flies (Drosophila melanogaster) -pioneer in the use of fruit flies to.](https://reader036.fdocuments.net/reader036/viewer/2022062321/56649f0d5503460f94c21e48/html5/thumbnails/42.jpg)
2) Ultrasound: High frequency soundwaves “echo” from the fetus, and givea picture.-can be used to see any physical abnormalities.EX: limb development, internal organs
DNA needs to be in the form of chromosomes to be seen clearly.Sex of fetus can also be determined.
![Page 43: -Sex (gender) Determination Dr. Thomas Hunt Morgan (1866-1945) -worked with fruit flies (Drosophila melanogaster) -pioneer in the use of fruit flies to.](https://reader036.fdocuments.net/reader036/viewer/2022062321/56649f0d5503460f94c21e48/html5/thumbnails/43.jpg)
3) Fetoscopy:fetus is viewed with a small camera called an endoscope.
The endoscope is inserted through a small incision in the mothers abdomen.
![Page 44: -Sex (gender) Determination Dr. Thomas Hunt Morgan (1866-1945) -worked with fruit flies (Drosophila melanogaster) -pioneer in the use of fruit flies to.](https://reader036.fdocuments.net/reader036/viewer/2022062321/56649f0d5503460f94c21e48/html5/thumbnails/44.jpg)
EX: heart septum repairs, digestivetract repairs.
Small samples of tissue or blood maybe taken, some surgical procedures are now performed.