Alleles/Other

Question 1

What is the difference between homozygous and heterozygous?

Answer 1

Heterozygous - 2 different alleles at a given locus

Homozygous - 2 identical alleles at a given locus

Question 2

What is a phenotype?

Answer 2

The physical result of a given genotype

Question 3

What’s the difference between dominant and recessive?

Answer 3

Dominant genes only need one allele to be the phenotype whereas recessive genes need two of the same .

Question 4

What are alleles?

Answer 4

One or more versions of a gene

Question 5

What is a genotype?

Answer 5

The entire set of genes in a cell

Question 6

What is co-dominance?

Answer 6

When one allele does not completely dominate the other and so the two phenotypes co-exist
E.g. When a brown cow and a white cow reproduce, the offspring is born with brown and white spots.

Question 7

What is Incomplete dominance?

Answer 7

When one allele does not completely dominate the other and so the two phenotypes ‘mix’ together and create a new phenotype altogether.
E.g. The offspring of a red flower and a white flower is pink.

Question 8

What is pedigree?

Answer 8

A genetic family tree.

Question 9

How do you know if a disease is sex-linked?

Answer 9

• if females are the only carriers

- if most of the people with the disease are male.

Question 10

Which chromosome carries the disease in sex-linked diseases?

Answer 10

The X chromosome.

This is how females can be carriers because they are able to mask the disease.