Key Definitions

Question 1

Definition of Chromosomes

Answer 1

Long molecules of DNA. We have 23 pairs in the human body

Question 2

Definition of gene

Answer 2

A section of DNA that controls a characteristic

Question 3

Definition of allele

Answer 3

Differing forms of genes e.g eye colour is blue, green, brown

Question 4

Definition of dominant

Answer 4

Represented as capital letter in a cells phenotype. Only one copy present for that characteristic to be expressed

Question 5

Definition of recessive

Answer 5

Represented as lower case. Only expressed when two copies of the allele is present e.g blue eyes only expressed when bb

Question 6

Definition of homozygous

Answer 6

Two of the same alleles for a gene e.g BB or bb

Question 7

Definition of heterozygous

Answer 7

Different alleles present for the same gene e.g Bb

Question 8

Definition of genotype

Answer 8

Alleles present

Question 9

Definition of phenotype

Answer 9

Physical appearance resulting from inherited information

Question 10

Definition of zygote

Answer 10

Fertilised egg cell

Question 11

Definition of gamete

Answer 11

Mature haploid sex cell (sperm and egg)