Unit 4: SAC 2: Genetics

Question 1

Gene

Answer 1

A segment of DNA that occupies a particular locus on a chromosome.

Question 2

Alleles

Answer 2

The possible variations that can occur to each gene. The variations of a gene are called alleles.

Question 3

Homozygous

Answer 3

When two genes have the same alleles they are said to be homozygous. Homozygous is represented by the same letters.

Question 4

Heterozygous

Answer 4

When two genes have different alleles on the same locus they are said to be heterozygous. Heterozygous alleles are represented by different letters and have one dominant and one recessive allele.

Question 5

Homozygous dominant

Answer 5

Two dominant alleles

Question 6

Homozygous alleles

Answer 6

Two recessive alleles.

Question 7

Dominant trait

Answer 7

As genes occur in pairs, when an allele on one chromosome expresses its effect over the partner allele, that allele is said to be dominant.

Question 8

Recessive trait

Answer 8

When the expression of an allele on a chromosome is masked by the other matching allele, that allele is said to be recessive. That characteristic will only be expressed, when both recessive allele are inherited.

Question 9

Genotype

Answer 9

The organisms genetic makeup. It is shown by using letters that make up the organism.