Take this Exam: GCSE Biology: Inheritance and Genetics | Zestly

Question 1

In a genetic cross where 'B' is the dominant allele for brown eyes and 'b' is the recessive allele for blue eyes, what is the probability of a child having blue eyes if both parents are heterozygous (Bb)?

Accepted Answer

25%

Question 2

Polydactyly is a condition caused by a dominant allele. If one parent is heterozygous (Dd) and the other is homozygous recessive (dd), what is the probability that their offspring will have polydactyly?

Accepted Answer

50%

Question 3

Cystic fibrosis is a recessive disorder. Which genotypes would result in a person being a 'carrier' of the disorder without having the symptoms?

Accepted Answer

Heterozygous

Question 4

How is the sex of a human offspring determined?

Answer

By the mother's egg cell

Answer

By the combination of X and Y chromosomes from the parents

Answer

By the environment during development

Answer

By the number of autosomes inherited

Question 5

Which of the following statements about sex chromosomes are correct?

Answer

Males have one X and one Y chromosome

Answer

Females have two Y chromosomes

Answer

Females have two X chromosomes

Answer

The mother determines the sex of the child