genesdef1

Question 1

Gene.

Answer 1

A sequence of bases on a DNA molecule that codes for a protein (polypeptide) which results in a characteristic.

Question 2

Allele.

Answer 2

One of a number of different forms of a gene - order of DNA bases is slightly different so code for different versions of the same characteristic.

Question 3

Genotype.

Answer 3

The genetic constitution of an organism - the alleles an organism has.

Question 4

Phenotype.

Answer 4

The expression of the genetic constitution and its interaction with the environment - an organism’s characteristics.

Question 5

Dominant.

Answer 5

An allele whose characteristic is always expressed, except if homozygous recessive.

Question 6

Recessive.

Answer 6

An allele whose characteristic is only expressed if homozygous recessive.

Question 7

Codominant.

Answer 7

Alleles that are both expressed in the phenotype.

Question 8

Locus.

Answer 8

Fixed position of a gene on a chromosome.

Question 9

Homozygote.

Answer 9

An organism that carries two copies of the same allele.

Question 10

Heterozygote.

Answer 10

An organism that carries two different alleles.

Question 11

Carrier.

Answer 11

A person carrying an allele which is not expressed in their phenotype, but can be passed on to offspring.