Biology key terms

The region that becomes coloured when the target substance, such as hCG, has been detected.

The main male reproductive hormone; it is produced by the testes and stimulates sperm production.

The production of an embryo with the same genes as a patient so that embryonic stem cells can be obtained for medical treatment without rejection by that patient’s body.

A temperature-sensitive receptor that detects a change in temperature.

The control of body temperature to keep internal conditions suitable for cells.

A coordination centre in the brain that monitors body temperature and brings about responses when it changes.

An endocrine gland in the neck that produces thyroxine when stimulated by TSH.

A hormone released by the thyroid gland that stimulates basal metabolic rate and is important for growth and development.

A group of similar cells working together to perform a particular function.

Growing new plants from small pieces of plant tissue in a nutrient-containing medium.

The fluid surrounding body cells, through which substances are exchanged between the blood and cells.

The comparison of donor and recipient tissue types to reduce the chance that a transplanted organ will be rejected.

A widespread plant virus that causes a mosaic pattern of leaf discolouration and reduces plant growth by reducing photosynthesis.

The range of environmental conditions within which an organism can survive and reproduce.

The extent to which a substance can harm the body.

A poisonous substance produced by some bacteria that damages tissues and makes the host feel ill.

A compromise in which gaining one benefit involves accepting a cost, risk or disadvantage elsewhere.

The production of a complementary messenger RNA strand using the DNA of a gene as a template.

The conversion of one form of energy or information into another; in the retina, light is converted into electrical signals.

A line across a habitat along which samples are taken to investigate changes in distribution.

The fraction or percentage of the available biomass that is transferred to the next trophic level.

A medical risk in which transplanted cells carry a virus into the recipient, potentially causing infection.

An organism containing genetic material introduced from another species by genetic engineering.

The stage of protein synthesis in which the sequence of bases in mRNA determines the sequence of amino acids joined into a polypeptide at a ribosome.

Changing information from one representation into another while preserving its scientific meaning.

The movement of dissolved food molecules, particularly sugars, through phloem to other parts of a plant.

The transfer of a pathogen from one organism or source to another organism.