DNA

Question 1

Which is the dominant gene; blue eyes or brown eyes?

Answer 1

Brown eyes.

Question 2

What is an allele?

Answer 2

An allele is a different version of a gene. These come in pairs from the parents. The dominant gene is the physical appearance, but the other gene is still there.

Question 3

What do you call a gene which is not dominant?

Answer 3

Recessive

Question 4

What is the probability a child has blue eyes if they have a homozygous brown eyed parent and a homozygous blue eyed parent?

Answer 4

\Dad | B | B
Mom\
b | Bb | Bb
b | Bb | Bb

Answer - 0% chance of blue eyes

Question 5

Paul and Emily have sickle cell. They have five children, only Luna without sickle cell. Teresa, Lee, Cristina and Simon have sickle cell. Teresa and Sam (who does not have sickle cell) have 4 children - Ruby, Luke, Hester and Malcolm. What is the probability that Hester has sickle cell?

Answer 5

\Teresa | S | s
Sam\
s | Ss | ss
s | Ss | ss

There is a 50% chance that Hester has sickle cell

Question 6

What is Polydactyly?

Answer 6

A dominant allele causing multiple fingers for example