Genetic Variation Terms

molecule containing the genetic information that makes up the chromosomes.

tightly coiled DNA located within the nucleus

A section of DNA that codes for a specific trait

An alternative form of a gene.

A pair of chromosomes carrying the same sequence of genes

A part of the cell containing DNA

combination of alleles for a gene

observable characteristics determined by your genotype

An organism that has two different alleles for a gene. Eg Bb

An organism that has two identical alleles for a gene. Eg BB or bb

An allele that is always expressed in the phenotype

An allele that is not expressed unless two copies are present in the genotype

An organism that is homozygous for a trait

the crossing of an individual of unknown genotype with a homozygous recessive individual to determine the unknown genotype

containing two complete sets of chromosomes

having a single set of unpaired chromosomes

Fusing of a male gamete with a female gamete.

Differences in DNA within a species

a type of cell division that creates gametes

permanent change in the DNA base sequence

A process where individuals who are best suited to their environment are more likely to survive and reproduce, passing on their favourable alleles.

Individuals that are homozygous that will always produce the same offspring when crossed together

in each new DNA double helix, one strand is from the original molecule and one strand is new

body cell

Sex cell, such as sperm or egg.

a type of cell division that results in two identical cells for growth and repair

A building block of DNA, consisting of a base, sugar and phosphate

fertilized egg

A person who is heterozygous for a recessive disorder

A reproductive process that involves only one parent and produces offspring that are identical to the parent.

A reproductive process that involves two parents that combine their genetic material to produce a new organism, which genetically differs from both parents