Genetic Inheritance And Interactions

Question 1

Explain what a phenotype is

Answer 1

The physical traits inherited from the parents

Question 2

What is an allele

Answer 2

A variant of a gene

Question 3

Explain what a genotype is

Answer 3

A genetic characteristic inherited from the parents

Question 4

What is a gene

Answer 4

A section of DNA

Question 5

What does homozygous mean

Answer 5

2 copies of the same allele

Question 6

What does heterozygous mean

Answer 6

2 copies of a different allele

Question 7

Explain lethal alleles

Answer 7

These lead to death in the animals that have them. They can be dominant or recessive.

Question 8

Explain incomplete dominance

Answer 8

Neither allele is completely dominant to the other. This produces a new phenotype where the heterozygous animal will look different to both homozygous animals.

Question 9

Explain Codominance

Answer 9

Neither allele is completely dominant to the other. Both alleles are shown at the same time in the phenotype.

Question 10

Explain epistatic effects

Answer 10

This is where one gene affects the expression of another gene

Question 11

Explain sex-linkage

Answer 11

This is where genes are carried on the sex chromosomes (X or Y)

Question 12

Explain sex-influenced

Answer 12

The phenotype depends on the gender of the animal, It is influenced by sex hormones.

Question 13

Explain multiple alleles

Answer 13

Three or more alternative alleles of a single gene are possible

Question 14

Give some examples of lethal alleles

Answer 14

1. Creeper disease in chickens
2. Yellow fur in mice
3. Roan & Dalmatian colouring in Guinea pigs
4. Parrot jaw in cattle
5. Overo lethal white foal syndrome