Harper BIO101 Abnormal Chromosome Number Latest 2020 MAY

BIO101 Biology Survey

Abnormal Chromosome Number

1.  List the chromosomal abbreviations of the following aneuploid syndromes:

A.  Kleinfelter’s Syndrome

B.  Jacob’s Syndrome-

C.  Poly-X or Triplo X

D.  Turner Syndrome

E.  Embryonic Lethal (from sex chromosomes)

F.  Edward Syndrome

G.  Patau Syndrome

2.  List the physical characteristics of each of the syndromes above. 

A.  Kleinfelter’s Syndrome

B.Jacob’s Syndrome

C.Poly-X or Triplo-X

D.Turner Syndrome

Embryonic Lethal (one combination from sex chromosome aneuploidy)

F.Edward Syndrome

G.  Patau Syndrome

There is an example at the end of this assignment to help you draw the answers to questions 3-5.

3.  On a separate sheet of paper, draw a diagram to show how nondisjunction can occur during Meiosis I that results in Trisomy 21 after fertilization.

•             Begin with a cell with 46 chromosomes (human). 

•             You only have to draw the homologous pair of chromosome 21, however you have to label the total number of chromosomes for each cell throughout the whole process.  (There is an example on the next page for nondisjunction during Meiosis II)

•             “Fertilize” the gametes produced after Meiosis II to show how Trisomy 21 would result

4.  On a separate sheet of paper, draw a diagram that demonstrates how nondisjunction during oogenesis (egg formation) could result in an embryo with one of the sex chromosome abnormalities on the first page.  Start with a cell with two X chromosomes.  At the end, fertilize the egg with a “normal” sperm with either an X or Y chromosome to show the possible karyotypes that can result.

 

5.  On a separate sheet of paper, draw a diagram that demonstrates how nondisjunction during spermatogenesis (sperm formation) could result in an embryo with one of the sex chromosome abnormalities on the first page.  Start with a cell with one X and one Y chromosome.  At the end, fertilize a normal egg (with one X chromosome) with one of the abnormal sperm produced.

Be sure to include the number of chromosomes the cells have after each cell division completes, as well as after fertilization.Be sure to show what chromosomal abnormality forms in the zygote.  (Use 21’s, X’s and Y’s, as well as the name of the disorder).   There is an example on the next page for Edward Syndrome.