Glossary  (Page 2/18)

Anaemia A deficiency disease caused by lack of iron which reduces the number of red blood cells, affecting the flow of oxygen to the tissues

Anaerobic Does not use oxygen

Analagous Doing the same job as the other structure; compare with ‘homologous’

Androgen Male sex hormone produced by the testes; they develop and maintain the male sexual characteristics eg. testosterone

Aneuploidy A mutation in which the number of chromosomes changes eg.47 chromosomes in Down’s syndrome

Anorexia A disease in which a person refuses to eat and cannot see that s/he is becoming ill

Anterior To the front of the organism

Anther The box on top of a stamen where pollen is made

Antibody A protein in the blood which fights disease; made in response to the presence of foreign substances

Antibiotic A chemical substance made by a micro-organism that stops the growth of other micro-organisms

Antigen A substance which is foreign to the body and causes antibodies to be made

Antiseptic A chemical that kills germs such as bacteria and fungi

Aorta The largest artery in the body, leading from the left ventricle of the heart to all the body except the lungs

Aqueous humour The watery material filling the space in front of the lens of the eye

Arachnoid The middle of the three membranes covering the brain and spinal cord

Artery A blood vessel which carries blood away from the heart towards capillaries

Assimilation (in nutrition) Becoming a part of the body

Asthma Disease causing breathing difficulty; it is often caused by an allergen

Atherosclerosis A deposit of fatty substance leading to raised blood pressure and heart disease

Atom The smallest part of an element which has the properties of that element

ATP Adenosine Triphosphate, a chemical that holds energy for the cell (see ADP)

Atrium The chamber of the heart which collects blood from veins and passes it to the ventricle

Autonomic Self- governing and so acting without conscious thought ie. involuntary

Axon A long extension of a nerve cell carrying an impulse away from the cell body

Bacteria A very small single celled organism of the kingdom Prokaryota

Bar graph Graph using separate columns that is used when the independent variable is not numerical eg types of food

Benedict's reagent A blue solution with Copper salts that gives a red precipitate when boiled with a reducing sugar.

Beriberi The deficiency disease caused by lack of vitamin B1 (thiamine). Symptoms include paralysis of the digestive system and poor co-ordination

Bicarbonate indicator A substance that contains bicarbonate and changes colour with different acidity (red<pH7, yellow>pH7)

Bicuspid The heart valve which lies between the left atrium and the left ventricle

Bile An alkaline juice made by the liver that emulsifies fats and neutralises acidity when it enters the duodenum through the bile duct

Binary fission A form of asexual reproduction in single-celled organisms when they split into two equal cells

Biochemistry The study of the working of the chemicals of the body

Biodiversity The whole variety of living things found in that defined environment