Chapter 2 - E1

Question 1

What is the idea of the blending theory of heredity?

Answer 1

Traits are presented as a mixture of the characteristics passed down from the parents
- Ex: red flower mother + white flower father = pink offspring

Question 2

Pure/True Breeding individuals

Answer 2

Strains that consistently produce the same phenotype

- homozygous dom or recessive

Question 3

What does the “F” in F1, F2, F3 stand for?

Answer 3

Filial generation

Question 4

What is a reciprocal cross?

Answer 4

Where the donating sex is alternated to see if the trait is linked to a certain sex

Question 5

What is a test cross?

Answer 5

Where you cross and individual with a dominant phenotype to a pure-breeding recessive individual to identify the genotype of the dom individual

Question 6

What is the phenotypic ratio in the F2 generation of a monohybrid cross?

Answer 6

3:1, Dom:Recessive

Question 7

What is particulate inheritance?

Answer 7

The idea that each plant carries two alleles for each trait

Question 8

What is the genotypic ratio in the F2 generation of a monohybrid cross?

Answer 8

1:2:1 - Homo dom: hetero: homo recessive

Question 9

What is the Law of Segregation?

Answer 9

Two alleles seperate during gamete formation

Question 10

What is the genotype and phenotype of a dihybrid?

Answer 10

Heterozygous for both traits but display the dominany phenotype

Question 11

In a cross between RrGg and RrGg, what are the gametes formed?

Answer 11

RG, rG, Rg, rg

Question 12

What is the phenotypic ratio for a dihybrid cross?

Answer 12

9:3:3:1

Both dom: one trait dom: one trait dom: both recessive

Question 13

What is a trihybrid cross?

Answer 13

Cross involving 3 traits

Question 14

How many genotypes are there for AaBbCc?

Answer 14

2^n where n=heterozygous traits

2^3 = 8 genotypes

Question 15

What is the phenotypic ratio of a trihybrid cross?

Answer 15

27:9:9:3:9:3:3:1

Question 16

When do you use the product rule?

Answer 16

When 2 or more events are independent, multiply the probabilities if each were to occur

• Ex: What is the probabilty that 2 coins will both land on heads?
• – 1st coin: 1/2 —–2nd coin: 1/2 = 1/2 x 1/2 = 1/4

Question 17

What is special about conditional probability?

Answer 17

Use both the product and sum rule
Applied to a specific outcome
- Ex: what is the probabilty that yellow plants are herozygous like the parents?
—–Do NOT consider any plant that is not yellow

Question 18

What is the formula for a chi square analysis test?

Answer 18

Sum of (O-E)^2/E

Question 19

Correlation between chi square and p-value?

Answer 19

High chi square value = low p value

Question 20

How do you find the degrees of freedom?

Answer 20

n-1

n = the number of independent variables

Question 21

What does it mean if the p value is significant? Not significant?

Answer 21

Hypothesis of chance is rejected

Fail to reject chance hypothesis

Question 22

If individuals who are AaBBCcdd and AabbCcDd are crossed, what is the probability of having offspring with the genotype aaBbCcdd?

Answer 22

For A: 1/4
For B: 4/4
For C: 2/4
For D: 2/4
Multiply all these together = 16/256 = 1/16

Question 23

Characteristic of Autosomal Dominant traits

Answer 23

2 unaffected parents will have no affected offspring

2 affected parents can have unaffected offspring

Question 24

Characteristic of Autosomal Recessive traits

Answer 24

Parents with affected offspring are often unaffected

If both parents are affected, all children will be affected