A2 Genetics

Question 1

Define Gene

Answer 1

Sequence of bases on a DNA molecule that code for a protein, resulting in a characteristic

Question 2

Define Allele

Answer 2

Different version of a gene. Most organisms carry two alleles of each gene, one from each parent. They code for different versions of the same characteristic. Represented by letters (B or b)

Question 3

Define Genotype

Answer 3

Genetic constitution of an organism - alleles an organism has (BB, Bb or bb)

Question 4

Phenotype

Answer 4

Expression of genotype and its interaction with the environment - organisms characteristics

Question 5

Define Codominant

Answer 5

Alleles that are both expressed in the phenotype - neither one is recessive

Question 6

Locus

Answer 6

Fixed position of a gene on a chromosome - alleles of a gene found at same locus on each chromosome in a pair

Question 7

Heterozygote

Answer 7

Organism that carries two different alleles (Bb)

Question 8

Homozygote

Answer 8

Organism that carries two copies on same allele (BB or bb)