WEEK 1

Question 1

Genetic Interaction

Answer 1

= Different combinations of alleles from two or more genes can result in different phenotypes, because of interactions between their products at the cellular/biochemical level

Question 2

Complementation

Answer 2

= When 2 strains of an organism with different homozygous recessive mutations that produce the same phenotype produce offspring of the wild-type phenotype when crossed

• ONLY occurs if mutations are in different genes!
• the other genome supplies the wild-type allele to complement mutated allele

Question 3

Heterogeneous trait

Answer 3

= a mutation in any one of a number of genes can give rise to the same phenotype, ex: Deafness

Question 4

Epistasis

Answer 4

= the masking of the expression of one gene by another, no new phenotypes produced (the epistatic gene does the masking of the hypostatic gene)

Question 5

Difference dominance vs. Epistasis

Answer 5

Dominance happens at one gene, where one allele on the gene is dominant over another
Epistasis = Intergene = one GENE masks another GENE at another location

Question 6

Recessive Epistasis

Answer 6

= homozygous recessives at one gene pair masks expression from the other gene

Question 7

Dominant Epistasis

Answer 7

= one dominant allele at one gene masks expression from other gene

Question 8

Pleiotropy

Answer 8

= A single gene can be responsible for a number of distinct and seemingly unrelated phenotypic effects = influences many different phenotypes

Question 9

Heterosis

Answer 9

= hybrid vigor = when two different inbred lines are crossed, the hybrids are heterozygous for many genes and display hybrid vigor
- Inbred parents were homozygous for all those alleles

Question 10

Hardy Weinberg Principle: Assumptions

Answer 10

• Population must be large
• there must be random matings
• must be unaffected by things like mutation, migration or natural selection

Question 11

Hardy-Weinberg Principle: Prediction 1

Answer 11

• if assumptions met:

= the allelic frequencies of a population do not change

Question 12

Hardy-Weinberg Principle: Prediction 2

Answer 12

• if assumptions met:

= the genotypic frequencies stabilize (will not change) after one generation

Question 13

Hardy-Weinberg Equilibrium

Answer 13

= the frequencies of both the alleles and the genotypes are not changing/ have stabilized
- genotype frequencies are now determined by allele frequencies

Question 14

Hardy-Weinberg Equation

Answer 14

1) p^2 + 2pq + q^2 = 1

2) p + q = 1

Question 15

Hardy-Weinberg Allele frequencies

Answer 15

p^2 = AA
2pq = Aa
q^2 = aa

Question 16

When is the Hardy-Weinberg Principle a correct prediction?

Answer 16

= in the absence of evolutionary influences like non-random matings, unequal survival, population subdivision, and migration

Question 17

Hardy Weinberg Allele Frequencies

Answer 17

p and q

Question 18

F2 ratio in monohybrid cross with complete dominance?

Answer 18

3:1

Question 19

F2 ratio in monohybrid cross with incomplete dominance or codominance?

Answer 19

1:2:1

Question 20

F2 ratio in monohybrid cross with a recessive lethal allele?

Answer 20

2:1

Question 21

F2 ratio in a dihybrid cross with complete dominance

Answer 21

9:3:3:1

Question 22

F2 ratio in a dihybrid cross with recessive epistasis?

Answer 22

9:3:4

Question 23

F2 ratio in a dihybrid cross with complementation?

Answer 23

9:7

Question 24

F2 ratio in a dihybrid cross with dominant epistasis?

Answer 24

12:3:1