Part G: Lecture 22A

Question 1

crossovers occur in ___

Answer 1

almost all meioses

Question 2

primary purpose of crossovers

Answer 2

hold homologous chromosomes together

Question 2

crossovers are detectable if ____

Answer 2

one parent is heterozygous for two (or more) genes

Question 3

alleles can be in a ___ or ___ configuration

Answer 3

coupling
repulsion

Question 4

coupling configuration

Answer 4

dominant alleles of genes on same chromosome

Question 5

repulsion configuration

Answer 5

dominant alleles of genes on different chromosomes

Question 6

crossovers if genes are autosomal

Answer 6

AB/ab x ab/ab

Question 7

crossovers if genes are sex-linked/X

Answer 7

AB/ab x ab/Y

Question 8

Genetic maps tell us ____

Answer 8

the relative position of genes (not left & right)

Question 9

crossovers do not occur in ___ drosophila

Answer 9

male

Question 10

calculated RFs do not exceed __ no matter how how far apart two genes are because ____

Answer 10

50% because crossovers cancel each other out

Question 11

meiotic recombination is used to _____

Answer 11

map genes in model organisms

Question 12

requirements for mapping with meiotic recombination

Answer 12

-a chromosome map
-genetic markers

Question 13

Genetic marker (def.)

Answer 13

a mutation at a known location on the chromosomes (ex. mutant allele of A-gene)

Question 14

Two-point test cross

Answer 14

test cross for mapping two genes

Question 15

RF > 50% indicates ___

Answer 15

an error

Question 16

three-point test cross

Answer 16

test cross for mapping three genes