Genetics Terminology Quiz

DNA – Deoxyribonucleic acid. This stores our genetic information, including instructions to make new cells.

Gene – A gene is a small section of DNA on a chromosome that codes for a specific sequence of amino acids, to make a specific protein.

Genome – The whole collection of DNA that each individual has.

Gene pool – The whole collection of genes that are present in a breeding population.

Chromosome – Long coiled-up parts of DNA that contain genes.

Allele – A particular version of a gene.

Heterozygous – When an individual has different alleles of a particular gene in their genotype.

Homozygous – When an individual has the same alleles of a particular gene in their genotype.

Genotype – The alleles an organism has for a particular gene.

Phenotype – The physical characteristics of an organism, determined by its genotype and environmental factors.

Zygote – An egg cell that has been fertilised by a sperm cell.

Gametes – The male and female sex cells – sperm and eggs.

Haploid – Cells that contain only half of the genetic material contained within the genome. Sperm and egg cells are haploid.

Diploid – Cells that contain the full set of DNA within the genome.

Recessive allele – Recessive alleles are not expressed unless they are the only alleles present in the genotype. Recessive alleles can lead to diseases such as cystic fibrosis.

Dominant allele – Dominant alleles are always expressed, so long as they are present in the genotype for a particular gene.