cytogenics flash

Question 1

Questions

Answer 1

answers

Question 2

Mitosis

Answer 2

Converts 2N–>4N–>2N (but with 2 cells). Nondisjunction called mosaicism.

Question 3

Meiosis

Answer 3

Generate haploid from diploid. Independent assortment. Crossing over.

Question 4

Crossing over

Answer 4

Meiosis prophase 1: Homologous chromosomes (chromatids) line up and crossover in area known as chiasma. Basis of genetic linkage.

Question 5

Acrocentric

Answer 5

Stalk

Question 6

Isochromosome

Answer 6

Abnormal centromere division. Iso-p or iso-q. Loss of genetic material.

Question 7

Robertsonian translocation

Answer 7

Translocation between acrocentric chromosomes, short acrostalk/ p is lost and the q’s fuse. 45 chromosomes, problem with gamete formation (33% normal)

Question 8

amniocentesis

Answer 8

0.5% risk, 15-16 weeks gestation, amniotic fluid obtained for cytogenetic study by placing needle in uterus

Question 9

chorionic villus sampling

Answer 9

0.5% risk, 10-12 weeks, remove cells from placenta (chorion) for cytogenetic study, remove mothers cells

Question 10

Cordocentesis

Answer 10

1-2% risk, 18 weeks, umbilical blood sampling