AQA GCSE Biology Key Terms

The specific pair of chromosomes in humans that determines an individual's biological sex.

The non-living factors in an ecosystem, such as light intensity and temperature.

A non-living part of an ecosystem that shapes its environment (e.g., temperature, light intensity).

The movement of small, soluble molecules from the small intestine into the bloodstream.

The practice of refraining from sexual intercourse entirely, representing the only 100% effective method of preventing pregnancy and STIs.

The total number of individuals of a specific species in a given area.

Organs that produce secretions to aid digestion but through which food does not physically pass.

The time allowed for an organism to adjust to a new environmental condition before data collection begins.

The process of changing the shape of the lens to focus on near or distant objects.

Rain that has become abnormally acidic due to dissolved pollutant gases such as sulfur dioxide and nitrogen oxides.

A small sac at the tip of a sperm cell's head containing digestive enzymes to break down the egg's protective coating.

The minimum amount of energy required for a collision between particles to result in a chemical reaction.

The region of an enzyme that is complementary in shape to a specific substrate where the reaction occurs.

The movement of substances from a more dilute solution to a more concentrated solution (against a concentration gradient), requiring energy from respiration.

The true, real-world dimension of a specimen being viewed under a microscope.

The four different nitrogenous bases found in DNA nucleotides.

Antidiuretic Hormone; a hormone released by the pituitary gland that increases the permeability of the kidney tubules to water.

The attraction between water molecules and the walls of the xylem vessels.

Glands located at the top of the kidneys that produce and secrete adrenaline.

A hormone produced by the adrenal glands that prepares the body for intensive action in response to fear or stress.

A fully developed cell from an organism (e.g., a skin cell) from which the nucleus is taken during adult cell cloning.

A type of asexual reproduction used to produce a genetically identical copy of an adult animal using a nucleus from a body cell.

Stem cells found in specific locations in adults, such as bone marrow, that can form many types of cells including blood cells.

A version of a gene that provides a survival or reproductive benefit in a specific environment.

The breakdown of dead organic matter by microorganisms in the presence of oxygen, primarily producing carbon dioxide and water.

A process where microorganisms use oxygen to break down organic matter, releasing carbon dioxide and water.

A jelly-like growth medium containing glucose, essential minerals, and plant hormones.

A solid nutrient-rich medium used for the cultivation of bacteria and other microorganisms.

The process where antibodies cause pathogens to clump together, preventing their spread and making it easier for phagocytes to engulf them.

Resources added to a farming system to increase crop or livestock yield, such as fertilisers, pesticides, and machinery.