Biology Glossary Flashcards
Abiotic
A physical or chemical factor affecting an ecosystem e.g. light intensity or temperature
Absorption
The movement of digested food molecules through the wall of the intestine into the blood
Accommodation
Adjustments made by the eye to produce a clear image on the retina
Accuracy
How close the result is to the ‘true value’
Acid rain
Rain that is more acidic than normal because various gases (often sulfur dioxide) have dissolved into it
Active
A process which requires energy to work
Active site
The part of an enzyme into which a substrate fits during a reaction
Active transport
Active movement of molecules from an area of low concentration to an area of high concentration, against a concentration gradient
Adaptation
A feature of an organism that is well suited to its function and helps the organism survive
Adenine
One of the nitrogenous bases found in DNA and RNA. Pair with thymine in DNA and uracil in RNA
ADH
A hormone produced by the pituitary gland which is involved in control of water levels in the body, makes the collecting duct more permeable to water
Adrenaline
A hormone produced by the adrenal gland in response to stressful situation. Affects the circulatory, respiratory and digestive systems
Aerobic respiration
Respiration that requires the presence of oxygen
Algal bloom
The rapid growht of algae resulting from an increased nutrient supply.
Allele
One of the alternative forms of a gene
Alveoli
The air sacs in the lungs where gas exchange takes place, site of gas exchange in the lungs
Amino acid
The monomer from which proteins are made, contain carbon, hydrogen, oxygen and nitrogen (some have sulfur)
Amnion
Membrane enclosing the embryo during pregnancy
Amniotic fluid
Fluid secreted by the amnion, which supports and protects the developing embryo
Amylase
An enzyme that digests starch into maltose. Produced in the mouth and pancreas
Anaerobic respiration
Respiration that takes place in the absence of oxygen
Animal
Multicellular organisms that have no cell walls, form zygotes after fertilisation and ingest their food
Anomaly
A reading which falls outside the normal, expected, range of measurements
Anther
the part of the stamen in which pollen is formed and from which it is released