Mendelian Genetics Extention

Question 1

What is the probability of getting ssyy offspring from SsYy x SsYy

Answer 1

Achieving ss - 1/2 for parent 1 supplying s. 1/2 for parent 2 supplying s = 1/4 (product rule)
Achieving yy - 1/2 for parent 1 supplying y. 1/2 for parent 2 supplying y = 1/4 (product rule)
Probability of both these events happening = 1/4 x 1/4 = 1/16

Question 2

When is the Product rule used

Answer 2

Independent events

Question 3

When is the sum rule used

Answer 3

Mutually exclusive events

Question 4

What is the probability of an Aa Bb cc offspring from a cross between Aa BB Cc x Aa Bb cc

Answer 4

Achieving Aa: Parent 1 supplying A = 1/2. Parent 2 suppling a = 1/2 (1/2 x 1/2 = 1/4)
OR parent 1 supplying a = 1/2. Parent 2 suppling A = 1/2 (1/2 x 1/2 = 1/4)
1/4 + 1/ = 1/2
Achieving Bb: Parent one suppling B = 1. Parent 2 supplying b = 1/2 (1 x 1/2 = 1/2)
Achieving cc: Parent 1 suppling c = 1/2. Parent 2 suppling c = 1 (1 x 1/2 = 1/2)

1/2 x 1/2 x 1/2 = 1/8

Question 5

What is polymorphism

Answer 5

The existence of two or more variants of a particular gene in a population

Question 6

What is incomplete dominance

Answer 6

When a F1 has intermediate phenotypes
Where both phenotypes exist side by side within the organism

Question 7

What are polygenic traits

Answer 7

Phenotype controlled by many genes that have an additive effect
Characters appear continuous or quantitative

Question 8

What is an additive effect

Answer 8

Phenotype determined by the total number of alleles that add together to contribute to final phenotype

Question 9

What represents the distribution of a typical polygenic train in a population

Answer 9

A normal distribution.
The more genes involved, the higher the number of phenotypic classes

Question 10

What effect do environmental factors have on phenotypes

Answer 10

Can allow/restrict a genotype from reaching full potential
Can smooth the differences between phenotypes