OCR GCSE Biology A key terms

A straight line across a habitat along which observations and measurements are made.

The process in the cytoplasm in which the nucleotide sequence carried by mRNA is used to assemble amino acids into a protein.

The movement of dissolved sugars and other organic substances through phloem from one part of a plant to another.

An electron microscope in which electrons pass through an extremely thin specimen to form a highly resolved image of its internal structure.

The loss of water vapour from a plant, mainly through openings in its leaves.

A continuous movement of water from the roots, through the xylem and towards the leaves, driven by water loss from the plant.

The transfer of living cells, tissue or an organ into a patient to replace damaged or diseased material.

An immune response in which a recipient's immune system recognises transplanted cells as foreign and attacks them.

A system that moves substances between exchange surfaces and cells throughout a multicellular organism.

A storage lipid formed from one glycerol molecule joined to three fatty acid molecules.

The use of successive groups of three bases along a gene to specify the order of amino acids in a protein.

Transfer RNA: a molecule that carries a specific amino acid to a ribosome during translation.

A food-chain position occupied by organisms with the same feeding role, such as producers or primary consumers.

Thyroid-stimulating hormone, released by the pituitary gland to stimulate the thyroid gland to release thyroxine.

A communicable bacterial disease that commonly affects the lungs.

A mass of cells produced by uncontrolled cell division.

A molecule on a cancer cell that may be recognised by a targeted antibody.

A form of diabetes in which the pancreas produces little or no insulin because the insulin-producing cells have been destroyed.

A disease in which the body cannot regulate blood glucose effectively, often because its cells respond less well to insulin.

How well a method prevents pregnancy in real life, including mistakes or failures in use.

The fine structural detail within a cell, including structures and internal features that cannot be resolved with a light microscope.

A cell that has not yet developed the adaptations for a particular specialised function and may be able to differentiate into other cell types.

A nitrogen-containing waste substance carried in human blood to the kidneys and removed in urine.

A liquid produced by the kidneys that contains urea, excess water and excess ions.

A preparation containing harmless pathogen material or its antigens that stimulates an immune response and produces immunity without causing the disease itself.

A structure that permits flow in one direction and prevents backflow.

Differences in characteristics between individuals of the same species.