Chapter 15: The Chromosomal Basis of Inheritance

Question 1

Chromosome theory of inheritance

Answer 1

1. Genes have specific locations (loci) on chromosomes
2. Chromosomes segregate and assort independently

Question 2

Sex chromosomes

Answer 2

X and Y chromosomes that determine the sex of an organism

Question 3

Sex-linked genes

Answer 3

Genes located on either sex chromosome

Question 4

Y-linked genes

Answer 4

Genes on the Y chromosome, very uncommon

Question 5

X-linked genes

Answer 5

Genes on the X chromosome

Question 6

Linked genes

Answer 6

Genes located on the same chromosome and generally inherited together

Question 7

Parental types

Answer 7

Offspring with a phenotype matching one of the parental (P) phenotypes

Question 8

Recombinant types/recombinants

Answer 8

Offspring with non-parental phenotypes (new combinations of traits)

Question 9

Recombinant gametes

Answer 9

Gametes with chromosomes that exchanged segments during crossing over, producing new combinations of alleles

Question 10

Linkage map

Answer 10

Genetic map that is based on % of cross-over events

Question 11

Nondisjunction

Answer 11

Pairs of homologous chromosomes do not separate normally during meiosis

Question 12

Deletion

Answer 12

Removal of a chromosomal fragment

Question 13

Duplication

Answer 13

Repeating of a chromosomal segment

Question 14

Inversion

Answer 14

Reversal of the orientation of a segment within a chromosome

Question 15

Translocation

Answer 15

Moving of a segment from one chromosome to another

Question 16

Aneuploidy

Answer 16

Abnormal number of chromosomes

Question 17

Down syndrome

Answer 17

Aneuploid condition resulting from three copies of chromosome 21