DNA 2 - Key Terms

Question 1

What is an allele?

Answer 1

Alleles are the different versions of a particular gene.

Question 2

What does ‘dominant’ mean in terms of alleles?

Answer 2

Dominant means only one allele has to be present for it to be expressed.

Question 3

What does ‘recessive’ mean in terms of alleles?

Answer 3

Recessive means that two alleles must be present for them to be expressed.

Question 4

How many alleles are present per gene in an individual?

Answer 4

2 alleles are present per gene.

Question 5

What does it mean to be ‘homozygous’ for a particular gene?

Answer 5

Both alleles in the gene are identical

Question 6

What does it mean to be ‘heterozygous’ for a particular gene?

Answer 6

The two alleles of that gene are different.

Question 7

What is the ‘genotype’ of an organism?

Answer 7

The two alleles present for a particular gene

Question 8

What is the ‘phenotype’ of an organism?

Question 9

Are most characteristics determined by: a single gene, a combination of multiple genes, or the combination of multiple genes and the environment?

Answer 9

Multiple genes and the environment