Chromosomal Abnormalities

Question 1

Define Nondisjunction

Answer 1

Means a pair of homologous chromosomes has failed to separate or segregate at anaphase so that both chromosomes of the pair pass to the same daughter cell.

Question 2

Define Trisomy

Answer 2

A condition in which an extra copy of a chromosome is present in the cell nuclei, causing developmental abnormalities.

Question 3

Define Monosomy

Answer 3

A form of aneuploidy with the presence of only one chromosome from a pair.

Question 4

Define Autosomes

Answer 4

Any chromosome that is not a sex chromosome.

Question 5

Define Sex Chromosomes

Answer 5

A type of chromosome involved in sex determination.

Question 6

Define Barr Body

Answer 6

A densely staining inactivated condensed X chromosome that is present in each somatic cell of most female mammals and is used as a test of genetic femaleness.

Question 7

Define Deletion (Chromosomal Abnormality)

Answer 7

It means that a part of a chromosome is missing or deleted.

Question 8

Define Duplication (Chromosomal Abnormality)

Answer 8

It means that a part of a chromosome is duplicated, or present in 2 copies

Question 9

Define Inversion (Chromosomal Abnormality)

Answer 9

A DNA rearrangement in which a segment of a chromosome is flipped between two break points, so that the sequence reads in the opposite direction to the original

Question 10

Define Translocation (Chromosomal Abnormality)

Answer 10

A genetic change in which a piece of one chromosome breaks off and attaches to another chromosome.