8.2

Question 1

What is independent assortment?

Answer 1

The principle that alleles for different traits segregate independently of one another during gamete formation

This principle is a key element of Mendelian genetics.

Question 2

How does independent assortment apply to a dihybrid cross?

Answer 2

It allows for the formation of different allele combinations in gametes, resulting in a variety of phenotypes in offspring.

A diagram illustrating this would show how alleles segregate during meiosis.

Question 3

How to set up a dihybrid cross?

Answer 3

Using a Punnett square or forked line diagram to illustrate allele combinations.

A Punnett square is often used for visualizing the genetic crosses.

Question 4

Define epistasis.

Answer 4

A genetic interaction where one gene suppresses the expression of another gene.

An example is when a gene for coat color affects the expression of a gene for pattern.

Question 5

In humans, what is the dominant allele for pigmented eyes?

Answer 5

B

The recessive allele for blue eyes is represented by ‘b’.

Question 6

In humans, what is the dominant allele for right-handedness?

Answer 6

R

The recessive allele for left-handedness is represented by ‘r’.

Question 7

What is the probability of a child with pigmented eyes and right-handed from a BbRr x BbRr cross?

Answer 7

9/16

This follows from the Mendelian F2 ratios for dihybrid crosses.

Question 8

What is the probability of a child with pigmented eyes and left-handed from a BbRr x BbRr cross?

Answer 8

3/16

This can be derived from the F2 ratios.

Question 9

What is the probability of a child who is blue-eyed and right-handed from a BbRr x BbRr cross?

Answer 9

3/16

This is calculated based on the allele combinations from the cross.

Question 10

What is the probability of a child who is blue-eyed and left-handed from a BbRr x BbRr cross?

Answer 10

1/16

This probability is also derived from the Mendelian ratios.

Question 11

What are the genotypes of the P generation in the horse coat color example?

Answer 11

BBTT (homozygous black trotter) and bbtt (chestnut pacer)

This shows the dominant and recessive traits for coat color and gait.

Question 12

What is the phenotype ratio of the F1 Generation from the horse coat color example?

Answer 12

All black trotters

The dominant traits mask the recessive traits in the F1 generation.

Question 13

What is the phenotype ratio of the F2 Generation from the horse coat color example?

Answer 13

9:3:3:1

This ratio represents the typical outcomes of a dihybrid cross.