Linkage And Recombination I

Question 0

Linkage keeps ________

Answer 0

particular genes together

Question 1

What are linked genes?

Answer 1

Genes located close together on the same chromosome

Belong to the same linkage group

Do NOT assort independently

Question 2

Crossing-over causes genes to _____

Answer 2

be mixed up

Question 3

MD/MD x md/md ->MD/md

Example of?

Answer 3

Linkage: M and D are linked

Linkage keeps particular genes together

Question 4

MD/MD x md/md -> MD/md, Md/Md

example of?

Answer 4

Crossing over

Question 5

Define recombination

Answer 5

The sorting of alleles into new combinations

Question 6

When does crossing over take place?

Answer 6

In meiosis

Question 7

What is responsible for recombination?

Answer 7

Crossing over in meiosis

Question 8

Gametes that contain only original combinations of alleles present in the parents are (recombinant/non-recombinant) gametes

Answer 8

nonrecombinant gametes

or also called parental gametes = MD and md

Question 9

MD/md x md/md is an example of what type of cross?

Answer 9

Test cross

Question 10

Progeny displays _______ of traits found in parents (P generation) and are nonrecombinant porgeny or parental progeny

Answer 10

original combinations

Question 11

MD/md x md/md ->

if nonrecombinant

Answer 11

1/2 MD/md

and 1/2 md/md

Question 12

MMDD x mmdd - >

If genes are not linked

Answer 12

MdDd

Question 13

Mm/Dd x md/md ->

If not linked

Answer 13

1/4 MmDd, 1/4 mmdd, 1/4 Mmdd, 1/4 mm/Dd

Question 14

MD and md are (recombinant/nonrecombinant) gametes

Answer 14

nonrecombinant

Question 15

Md and mD are (nonrecombinant/recombinant ) gametes

Answer 15

recombinant

Question 16

MmDd and mmdd are (nonrecombinant/recombinant) progeny

Answer 16

nonrecombinant

Question 17

Mmdd and mmDd are (nonrecombinant/recombinant) progeny

Answer 17

recombinant

Question 18

After a single crossover has taken place two chromatids that did not participate are unchanged. And the gametes that receive these chromatids are
(nonrecombinants/recombinants)

Answer 18

nonrecombinants

Question 19

After a single crossover has taken place, two chromatids that did particpate contain new combinations of alleles. Gametes that receive these chromatids are (nonrecombinants/recombinants)

Answer 19

recombinants

Question 20

For each meiosis in which a single crossover takes place, what type of gametes are produced? What are the end results of independent assortment vs linked genes?

Answer 20

Two nonrecominant gametes and two recombinant gametes will be produced. Same for both but there will be a 1.1.1.1 in independent assortment and linked will not be

Question 21

If there is no crossing over only (nonrecombinant/recombinant) gametes will be produced

Answer 21

nonrecombinant

Question 22

The frequency of recombinant gametes is always ____ the frequency of crossing over

Answer 22

50%

25+25

Question 23

The maximum proportion of recombinant gametes is what? Why?

Answer 23

50% because 2 alleles out of 4 cross over so 1/2

Question 24

The percentage of recombinant progeny produced in a cross is called what?

Answer 24

Recombination frequency

Question 25

Recombination frequency =

Answer 25

of recombinant progeny/total number of progeny x 100%

Question 26

What is coupling?

Answer 26

Wild-type alleles are found on one chromosome and mutant alleles are found on the other chromosome

Question 27

What is coupling aka?

Answer 27

cis configuration

Question 28

p+b+/pb

Answer 28

coupling

Question 29

What is repulsion?

Answer 29

One chromosome carries a wild allele and a mutant allele and other carries the other wild and other mutant

Question 30

What is repulsion aka?

Answer 30

trans configuration

Question 31

p+b/pb+

Answer 31

Repulsion

Question 32

Most numerous progeny types are those with either both wild-type or both mutant types is ______

Answer 32

coupling

Question 33

Most numerous progeny types are those with one wild-type and one mutant allele and those with the other wild-type and the other mutant allele is _____

Answer 33

repulsion