Exam 1: Basic Principles of Heredity

Question 1

Why are pees an ideal model?

Answer 1

Pheotypes are easily differentiated (discrete), produce many offspring, cross and self-fertilize, and reproduce quickly

Question 2

What were the conclusions of the monohybrid cross?

Answer 2

1. One characteristic is encoded by 2 genetic factors, or alleles
2. Two genetic factors, or alleles, sepereate when gametes are formed
3. Dominant vs. Recessive traits

Question 3

Principle of Segregation (Mendel’s First Law)

Answer 3

Each individual diploid organism possesses 2 alleles for any particular characteristic that segegate when genes are fomed and one alleles goes into each gamete.

Question 4

Backcross

Answer 4

F1 individual with one parental genotypes to test hypothesis of domincance between the alleles

Question 5

Testcross

Answer 5

Homozygous recessive individual with an unknown genotype (DD or Dd) - ratio of F1 tells you what the genotype is

Question 6

Dihybrid cross

Answer 6

F1: RrYy x RrYy
F2: 9:3:3:1

Question 7

Monohybrid Cross

Answer 7

F1: Rr x Rr
F2: 3:1