meiosis and autosomal abnormalities

Question 1

what is the point of meiosis?

Answer 1

to reduce the chromosome number from 46 to 23

Question 2

what is the gene content of the G bright spots?

Answer 2

they are AT rich and are rich in transcribed genes.

Question 3

which sex has the more frequent nondisjunction in Meiosis 1?what do you produce from nondisjunction in meiosis 1?

Answer 3

nondisjunction in meiosis 1 is most frequent in females. You produce 2 disomic gametes and 2 nullisomic gametes

Question 4

non disjunction in meiosis 2 happens most in which sex and what is the product you get?

Answer 4

happens most in men. you get 2 normal monosomic gametes, 1 disomic gamete and 1 nullisonic gamete

Question 5

differentiate meosis i males vs. females

Answer 5

a

Question 6

how do you tell where the nondisjunction happened looking at the chromosome of the child?

Answer 6

if you look at the CA repeats near or at the centromere you can judge. if the CA repeats are the same then the nondisjunction happened during meiosis 2 because at that point you have identical sister chromatids that split up but if the nondisjunction happened in meiosis 1 then you the CA repeats should be different because the homologous chromosomes are different

Question 7

uniparental disomy can cause what effects?

Answer 7

can cause mosaisizm as well as the passing of autosomal recessive traits from a heteozygote and homozygous dominant breed. it can also be the case when a father passes an X linked trait to their son.

Question 8

what are some physical findings in trisomy 21?

Answer 8

almond eyes, depressed nasal bridge brushfield spots, round head shape

Question 9

if you have time, look at the tests you will do on people of different ethnic origins

Answer 9

Question 10

what are some procedures you can dofor prenatal diognosis?

Answer 10

amnioscentesis, chronic villous sampling and percutaneous umbillical blood sampling