Genetics: Key terms

Question 1

What is genetics?

Answer 1

The study of heredity

Question 2

What is heredity?

Answer 2

The passing of traits from one generation to the next

Question 3

What are traits?

Answer 3

Inherited characteristics (Eg; Hair & Eye colour or behaviour/instincts)

Question 4

What is a genotype?

Answer 4

Particular combinations of alleles an organism has (Eg; TT, tt, Tt)

Question 5

What is a phenotype?

Answer 5

Physical or visible features determined by genotypes (Eg; Tall or short)

Question 6

What does it mean to be homozygous?

Answer 6

Organism contains the same two alleles for a trait (Eg; TT or tt)

Question 7

What does it mean to be heterozygous?

Answer 7

Organism contains two different alleles for a trait
(Eg; Tt)

Question 8

What is polygenic inheritance?

Answer 8

Traits are controlled by 2 or more pairs of genes. They show much variation.
(Eg; Height, skin and eye colour)

Question 9

What are sex linked genes?

Answer 9

Genes which carry only on the X chromosome

Question 10

What are sex linked traits?

Answer 10

Traits determined by sex linked genes
Examples:
Humans - RG colourblindness, Hemophilia
Fruit flies- Eye colour

Question 11

What are genes?

Answer 11

The basic unit of inheritance. A very specific part of a chromosome with specific DNA.

Question 12

What are alleles?

Answer 12

Alternative forms of genes (Eg; T and t are height alleles in pea plants)