Module 4

Question 1

Genes on the same chromosome go through - together

Answer 1

Meiosis

Question 2

What is crossing over?

Answer 2

When homologous chromosomes pair at meiosis, chromosomes occasionally break and exchange parts

Question 3

When does crossing over occur?

Answer 3

Meiosis

Question 4

What is a recombinant?

Answer 4

An individual organism or cell having a genotype produced by recombination

Question 5

What is recombination?

Answer 5

Any process in a diploid or partly diploid cell that generates new gene or chromosomal combinations not previously found in cell

Question 6

Physically linked alleles are inherited together or separately?

Answer 6

Inherited together

Question 7

What is a recombinant frequency?

Answer 7

The proportion of recombinant cells or individuals

Question 8

What are chromosome maps?

Answer 8

A representation of all chromosomes in the genome as lines, marked with positions of genes known

Question 9

What are chromosome maps based upon?

Answer 9

Based on analysis of recombinant frequency

Question 10

What can be seen as a major exception to Mendel’s second law?

Answer 10

Genetic linkage

Question 11

What is absolutely needed to calculate RFs?

Answer 11

You need recombinants and parental phenotypes

Question 12

What is coupling?

Answer 12

It indicates if the recessive alleles for two genes are flowing down to F1 from a single P0 parental, both recessive alleles in one parental

Question 13

What is repulsion?

Answer 13

Indicates if recessive alleles for two genes are flowing down to F1 from segregation of different P0 parental, one recessive alleles from each parental

Question 14

What is cis formation?

Answer 14

In a heterozygote having two mutant sites within a gene or within a gene cluster

Question 15

What is trans formation?

Answer 15

In a heterozygote with two mutant sites within a gene or gene cluster

Question 16

Coupling is related to - formation

Answer 16

Cis

Question 17

Repulsion is related to - formation

Answer 17

Trans

Question 18

What is the site of crossing over?

Answer 18

Chiasmata

Question 19

Where was the evidence for crossing over found?

Answer 19

Maize

Question 20

When does cross over happen?

Answer 20

At the end of meiosis

Question 21

How many chromatids are involved in crossing over?

Answer 21

2 out of 4

Question 22

If there was no crossing over, what would happen?

Answer 22

Only parental gametes formed

Question 23

If crossing over happened before DNA duplication, what would occur?

Answer 23

Outcome is 100% recombinant

Question 24

If crossing over happened after completion of meiosis I, what would occur?

Answer 24

100% parental gametes

Question 25

What is recombination caused by?

Answer 25

Physical exchange between homologous in prophase of first meiotic division and after S-phase

Question 26

How is frequency of double cross over calculated?

Answer 26

It is the product of frequencies of each event

Question 27

What is within the calculable values of RF?

Answer 27

50

Question 28

Calculations for RF

Answer 28

number of recombinant gametes/ P+ R gametes x 100

Question 29

What is deletion mapping?

Answer 29

The use of a set of known deletions to map new recessive mutations by pseudodominance

Question 30

What is duplication mapping?

Answer 30

Introducing extra wild type pieces of chromosomes can rescue recessive genotype

Question 31

What is a locus?

Answer 31

The chromosomal site where a specific gene is located

Question 32

What is interference?

Answer 32

The observed double crossover frequency differs from the expected double crossover frequency

Question 33

What is linkage?

Answer 33

The tendency for genes located in close proximity on the same chromosome to be inherited together

Question 34

The (higher, lower) the combination frequency, the farther apart two genes are on a chromosome

Answer 34

Higher

Question 35

What is the definition of a map unit?

Answer 35

Percent chance of a crossover between two locations on a chromosome