Lecture 26

Question 1

What is the cross to establish dominance?

Answer 1

cross 2 pure breeding strains to get F1 (dominant) phenotype

Question 2

If F1 is not uniform or shows intermediate traits…

Answer 2

allele interaction

Question 3

What does a reciprocal cross tell you?

Answer 3

F1 results same = gene is auotomsal

If results differ = gene is on a sex chromosome

Question 4

What is the expected result of dihybrid self cross and dihybrid intercross? (AaBb x AaBb)

Answer 4

expected F2 ratio = 9:3:3:1

if NOT, gene interaction

Question 5

What is the expected ratio of AaBb x aabb?

Answer 5

1:1;1:1

if NOT, genes are linked on same chromosome

Question 6

What is the multiplication probability rule?

Answer 6

Probability of 2 independent events both occurring

P(A and B) = P(A) x P(B)

use when BOTH events must occur

Question 7

What is the addition probability rule?

Answer 7

probability of A or B occurring

P(A or B) = P(A) + P(B)

Use when ANY one of multiple outcomes is acceptable

Question 8

What is the subtraction probability rule?

Answer 8

probability some happens = 1 - probability does NOT happen

“at least one”

Question 9

What is gambler’s fallacy?

Answer 9

if something doesn’t show up, it’s due to show up