OCR GCSE Biology B Key Terms

Non-living physical factors in an environment, such as light intensity, temperature, and water availability.

The non-living parts of an ecosystem, such as the atmosphere, water, soil, minerals, temperature, and sunlight.

A non-living part of an ecosystem, such as water content or temperature, that affects living organisms.

The non-living physical and chemical parts of an environment that affect living organisms, such as light intensity and temperature.

The natural detachment of plant parts, typically leaves or ripe fruit, stimulated by ethene.

A specialised layer of cells at the base of a leaf or fruit stalk where ethene-stimulated cell division causes detachment.

The movement of soluble molecules from the digestive lumen into the blood or lymph.

The number of individuals of a species within a specific habitat.

The process of allowing a plant to adjust to a new environment for a few minutes to ensure the transpiration rate has stabilized before taking readings.

The process of changing the lens shape (via ciliary muscles and suspensory ligaments) to focus on objects at different distances.

A measurement that is close to the true value; for example, using a gas syringe provides a more accurate volume than counting variably sized bubbles.

A biological stain used to visualise DNA and chromosomes, turning them a deep red or purple colour.

The minimum amount of energy required for a chemical reaction to occur when particles collide.

Immunity resulting from the body's own lymphocytes producing antibodies and memory cells.

A transport mechanism that requires an input of metabolic energy (ATP) from the cell to function.

The specific region on an enzyme where a complementary substrate binds and the reaction takes place.

The movement of substances against a concentration gradient across a cell membrane, requiring energy from respiration and specific carrier proteins.

The real-life size of a biological specimen before any magnification is applied.

One of the four chemical bases in DNA, which always pairs with Thymine.

Antidiuretic Hormone; released by the pituitary gland to increase the permeability of the kidney's collecting ducts when water levels are low.

A hormone produced by the pituitary gland that regulates water reabsorption in the kidneys by changing the permeability of the collecting ducts.

Endocrine glands located above the kidneys that produce adrenaline.

A hormone released from the adrenal glands in response to stress that prepares the body for intensive action.

Stem cells found in specific tissues of fully developed animals that are multipotent and primarily used for growth, repair, and replacement.

Undifferentiated cells found in specific tissues of developed organisms that can differentiate into a limited range of cell types.

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

An exothermic chemical reaction inside cells that uses oxygen to break down glucose and release energy.

The clumping together of pathogens caused by antibody binding, preventing their spread.

The specific bacterial pathogen responsible for causing Crown Gall Disease.

Acquired Immunodeficiency Syndrome; the late and severe stage of an HIV infection where the immune system is fundamentally broken.