Chapter 12

Question 1

Sex-linked gene

Answer 1

Gene that is located on either sex chromosome.

Question 2

Barr Body

Answer 2

Condensed inactive X chromosome in mammalian females. If the female is heterozygous for a particular gene on that X chromosome she will be a mosaic for that character.

Question 3

Linked Genes

Answer 3

Genes located on the same chromosome that tend to be inherited together.

Question 4

Linkage Map

Answer 4

A genetic map of a chromosome based on recombination frequencies.

Question 5

Map Units

Answer 5

Distance between genes. One map unit represents a 1% recombination rate.

Question 6

Genetic recombination

Answer 6

The production of offspring with combinations of traits that differ from either parent.

Question 7

Nondisjunction

Answer 7

Pairs of homologous chromosomes do not separate normally during meiosis I or sister chromatids do not separate during meiosis II. As a result, one gamete receives two of the same type of chromosome, and another gamete receives no copy.

Question 8

Polyploidy

Answer 8

A condition in which an organism has more than two complete sets of chromosomes. Common in plants but not animals.

Question 9

Translocation

Answer 9

Movement of a segment from one chromosome to another.