An enzyme that breaks down lactose.

A variety of rapid learning which occurs when ingestion of a characteristic food is followed by gastrointestinal upset. The flavour is avoided in the future. The effect is named after its discoverer, John Garcia, and is also termed taste-aversion learning.

Hormone released by endocrine cells in the small intestine in response to the presence of fats and glucose. GIP stimulates insulin release.

The unit of genetic information. Most genes code for the production of proteins.

We must consider mitosis and meiosis when looking at any pphysiological and psychological development. Meiosis is particular responsible for deciding on the birth sex, in that it passes either the XX or the XY gene into the fertilisation process. 

The total genetic material of a cell or organism.

The specific composition of alleles of a single gene, or the entire complement of genes of an organism. The information content that is inherited.

The cells in sexually reproducing organisms that give rise to gametes (ova in females and sperm in males). The gametes contain half the number of chromosomes of the somatic cells. When a sperm fuses with an ovum, a zygote is formed which goes on to develop into a new individual.

The line of cells that give rise to gametes, i.e. synonymous with germ cells. The term expresses the continuity of inheritance via the germ cells as a result of sexual reproduction.

Technical name for the scientific study of the elderly.