Genetic variation

Question 1

Genotype

Answer 1

Genetic constitution of an organism

Question 2

Phenotype

Answer 2

Physical characteristics (morphological, biochemical, molecular) of an organism or cell
Based on genotype +/- enivornment

Question 3

Locus

Answer 3

Location of a gene on a chromosome

Question 4

Allele

Answer 4

Alternative variant of a particular gene at that particular locus

Question 5

Polymorphism

Answer 5

At least 2 or more relatively common alleles of a gene in the population (>= 1%)
Eg. different alleles of genes responsible for ABO blood groups

Question 6

Dominant

Answer 6

Phenotype is dominant if trait is seen in individuals who are heterozygous for an allele (i.e. only need one copy)

Question 7

Recessive

Answer 7

Phenotype is recessive if trait is seen only in inidividuals homozygous for the allele (i.e. need both copes)

Question 8

Co-dominant

Answer 8

Effects of other alleles seen in the heterozygote

Question 9

Genetic heterogeneity

Answer 9

Multiple mutations in different genes causing the same conditions