MYP Biology Evolution Key Definitions

Traits that improve an organism’s chances of surviving and reproducing in its environment.

Speciation caused by geographical separation.

A long, double-helical molecule that stores genetic instructions.

Differences in traits between organisms or species.

An allele that is expressed even if only one copy is present (shown with a capital letter, e.g., R).

The population-level change in allele frequencies over generations, driven by selection, mutation, gene flow, and genetic drift.

A reproductive cell (sperm or egg) that contains half the usual number of chromosomes.

A section of DNA that codes for one protein.

A diagram showing the positions of genes or markers along DNA.

Having two different alleles (Rr)

Having two of the same alleles (RR or rr)

The transmission of genetic information from one generation to the next.

A small circular genome in mitochondria, inherited only from the mother.

A temporary copy of a gene used to carry instructions to the ribosome.

A process where individuals with advantageous traits survive and reproduce more successfully than others.

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

The period when physical and reproductive maturity develops.

An allele only expressed if two copies are present (shown with a lowercase letter, e.g., r)

The process by which living organisms produce new individuals to ensure the continuation of their species.

Each new DNA molecule keeps (“conserves”) half of the original DNA and builds the other half new.

Reading the nucleotide order (A, T, C, G) in DNA.

The process by which one species splits into two.

A group of organisms capable of interbreeding to produce fertile offspring.

Speciation that occurs without geographical separation.