Part J: Lecture 28

Question 1

F2 ratio of dihybrid intercross

Answer 1

9:3:3:1

Question 2

If F2 ratio of dihybrid intercross is not 9:3:3:1 then ___

Answer 2

gene interaction

Question 3

no gene interaction (def.)

Answer 3

when two gene independently contribute to a single phenotype (ex. corn snakes)

Question 4

no gene interaction F2 ratio

Answer 4

9:3:3:1

Question 5

If we a see a 9:3:3:1 phenotypic ratio in F2, it means… genes? chromosomes? interaction?

Answer 5

two genes
autosomal
on different chromosomes
no gene interaction

Question 6

order when determining genotypes of generation

Answer 6

F1 -> F2 -> P

Question 7

no gene interaction biochemical pathway

Answer 7

separate biochemical pathways

Question 8

complementary genes (def.)

Answer 8

when two genes are both needed to produce a WT phenotype (ex. petal colour in harebells)

Question 9

complementary genes F2 ratio

Answer 9

modified 9:3:3:1 ratio

Question 10

If we a see a modified 9:3:3:1 phenotypic ratio in F2, it means… genes? chromosomes? interaction?

Answer 10

two genes
autosomal
on different chromosomes
there is gene interaction

Question 11

genetic interactions (2)

Answer 11

allele interactions
gene interactions

Question 12

complementary genes statement

Answer 12

gene 1 and gene 2 show complementary gene action

Question 13

complementary genes biochemical pathway

Answer 13

-two enzymes in the same pathway
-two subunits of one enzyme

Question 14

duplicate genes (def.)

Answer 14

when either of two genes is needed to produce a WT phenotype (ex. seed coat colour in wheat)

Question 15

duplicate genes biochemical pathway

Answer 15

one pathway needs protein A or protein B

Question 16

discontinuous variation (def.)

Answer 16

when a character is found in two or more distinct forms in a population (2 seed colours in peas)

Question 17

continuous variation (def.)

Answer 17

when a character is found in a range of forms in a population (multiple hair colours in humans)

Question 18

continuous variation: one gene

Answer 18

3 phenotypic ratios

Question 19

continuous variation: two genes

Answer 19

5 phenotypic ratios

Question 20

continuous variation: three genes

Answer 20

can’t distinguish categories

Question 21

dominance (def.)

Answer 21

when one allele conceals another allele

Question 22

epistasis (def.)

Answer 22

when one gene conceals another gene

Question 23

Recessive epistasis

Answer 23

when the recessive phenotype of one gene conceals phenotype of second gene

Question 24

recessive epistasis statement

Answer 24

gene A is recessively epistatic to gene B

Question 25

recessive epistasis biochemical pathway

Answer 25

same linear pathway

Question 26

dominant epistasis

Answer 26

when the dominant phenotype of one gene conceals the phenotype of another gene

Question 27

dominant epistasis biochemical pathway

Answer 27

branched pathway

Question 28

linear pathway –> ____ epistasis

Answer 28

recessive

Question 29

branched pathway –> ____ epistasis

Answer 29

dominant

Question 30

5 types of gene interactions

Answer 30

none (A and B are independent)
complementary genes (A + B = wt)
duplicate genes (A or B = wt)
recessive epistasis (a/a masks B-gene)
dominant epistasis (A/__ masks B-gene)