Chapter 5

Question 1

genetic linkage

Answer 1

genes that travel together more often than not

Question 2

recombination

Answer 2

the separation of genes on the same chromosome

Question 3

syntenic

Answer 3

genes located on the same chromosome

Question 4

gametes that carry the allele combination seen in the original female or male of the P generation

Answer 4

parental types

Question 5

recombinant types

Answer 5

gametes that have allele combinations produced by reshuffling; not seen in the parental generation

Question 6

parental classes

Answer 6

the combinations originally present in the P generation

Question 7

recombination classes

Answer 7

combinations resulting from cross-overs

Question 8

linked genes

Answer 8

when the number of F2 progeny with parental genotypes exceeds the number of F2 progeny with recombinant genotypes

Question 9

physical markers

Answer 9

allowed the researcher to understand and see the process of recombination through experimental evidence

Question 10

genetic markers

Answer 10

alleles of genes that could serve as points of reference in determining whether particularly progeny were the result of recombination

Question 11

How does recombination contribute to genetic diversity?

Answer 11

Reshuffling the alleles of genes between homologous chromosomes.
Crossing-over also plays an even more critical role to ensure that chromosomes segregate properly when they are transmitted between parents and their progeny

Question 12

Cohesin

Answer 12

molecular complexes that involve the physical linkage between homologous chromosomes

Question 13

interference

Answer 13

ensures that each chromosome pair undergoes at least one crossovers, thus preventing nondisjunction of any chromosome except when rare mistakes occur

Question 14

recombination frequency reflects the distance between two genes

Answer 14

the closer two genes are on a chromosomes, the less their chance of being separated by an event that cuts and recombines the line of genes

Question 15

Alfred H. Sturtevant

Answer 15

Proposed that the percentage of total progeny who were recombinant types (recombination frequency) could be used as a measurement of the physical distance separating any two genes on the same chromosome

Question 16

Centimorgan

Answer 16

unit of distance between genes

Question 17

chromosomal interference

Answer 17

the phenomenon of crossovers not occurring independently

Question 18

coefficient of coincidence

Answer 18

frequency of observed/ frequency expected

Question 19

Interference

Answer 19

1- coefficient of coincidence

Question 20

recombination hotspots

Answer 20

small regions of DNA where the frequency of recombination is much higher than average

Question 21

linkage group

Answer 21

genes chained together by linkage relationships

Question 22

ascus

Answer 22

sac of four haploid products of each meiosis

Question 23

tetrad

Answer 23

the assemblage of four ascopores in a single ascus

Question 24

parental ditype (PD)

Answer 24

four spores in the resulting tetrad that have the parental configuration of alleles

Question 25

nonparental ditype (NPD)

Answer 25

four recombinant spores, two of each type

Question 26

teratype (T)

Answer 26

tetrad which contains four different kind of spores-- two recombinants (one of each type) and two parentals (one of each type)

Question 27

twin spots

Answer 27

adjacent islands of tissue that differ both from each other and from the tissue surrounding them

Question 28

mosaic

Answer 28

tissue of different genotype due to mistakes in mitotic division

Question 29

sectors

Answer 29

portions of a growing colony that have different genotype than the remainder of the colony