MYP Integrated Sciences Genetics and Evolution Key Definitions

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

Speciation caused by geographical separation.

The sequence of events that a cell goes through from one division to the next. Cells alternate between growing (interphase) and dividing.

The process by which one cell splits into two daughter cells. This is essential for growth, repair, and reproduction.

The aqueous, gel-like substance enclosed by the cell membrane that contains all organelles, dissolved nutrients, enzymes, and where many metabolic reactions occur.

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

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.

Cells that contain one set of chromosomes.

Having two different alleles (Rr)

Chromosome pairs (one from each parent) that carry the same types of genes.

Having two of the same alleles (RR or rr)

Random orientation of homologous pairs during metaphase, creating varied chromosome combinations.

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

A type of cell division that produces four genetically different haploid cells, each containing half the chromosome number of the parent cell.

A type of cell division used for growth and repair that produces two genetically identical daughter cells, each with the same number of chromosomes as the parent cell.

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 point where chromosome number is halved.