Uniparental disomy, genomic imprinting

Question 1

When does it occur?

Answer 1

when person receives two copies of a chromosome
from one parent and no copies from the other. (non-disjunction during meiosis I or
meiosis II)

Question 2

How it orginates?

Answer 2

1. Trisomic rescue – loss of chromosome from trisomic zygote
2. Monosomic rescue- duplication of chromosome on monosomic zygote

Question 3

Gamete contemplation?

Answer 3

fertilization of gamete w. two copies of chromosome w.

gamete w. no copies of chromosome

Question 4

Genomic imprinting?

Answer 4

when one copy of gene is silenced due to its parental origin
(from mother or father) certain genes are expressed in parent of origin specific
manner/epigenitc phenomenon/100 imprinted genes, results in silencing or
alterations in CHROMATIN not in DNA, Reversible process
If allele inherited from father is imprinted, it is thereby silenced, + only allele from
mother is expressed

Question 5

Parader willi syndrome?

Answer 5

several genes on ch 15 deleted or not expressed.

(hypoplastic dental abnormalities) + angels syndrome