4. chromosomal disorders

Question 1

what are the 3 main chromosomal abnormalities

Answer 1

• aneuploidy (too many/few c)
• rearrangement (translocations, inversions, CCRs)
• deletions/duplications

Question 2

where do whole chromosome aneuploidies occur

Answer 2

• gonads during meiosis = abnormal gametes
• during mitosis in germ line = mosaicism in gonad
• mitosis in early embryo = mocaicism in embryo

Question 3

what is malsegregation and what can it lead to

Answer 3

failure of chromosome to separate at metaphase = non disjunction
results in gametes (in meiosis), some are triatomic and some monosomic

Question 4

what does malsegregation in the germ line result in?

Answer 4

miotic error, results in GONADAL MOSAICISM

-mosaic embryo - different cells in the same individual have different numbers or arrangements of chromosomes