Organisms in the Environment

cellulose

A big carbohydrate molecule which makes up plant and algal cell walls.

limiting factors

Factors which limit the rate of reaction. e.g. temperature, pH, light levels (photosynthesis).

hydroponics

Growing plants suspended in water enriched with mineral ions rather than soil.

bacterial colony

A population of billions of bacteria grown in culture.

glucose

A simple sugar.

algal cells

The cells of algae, single-celled or simple multicellular organisms, which can photosynthesise but are not plants.

mineral ions

The chemicals needed in small amounts by living organisms.

nitrate ions

Mineral ions which are needed by plants to make proteins.

polytunnels

Large greenhouses made of plastic.

predator

An animal which eats other animals.

quadrat

A piece of apparatus for sampling organisms in the field.

quantitative sampling

Sampling which records the number of organisms and not just the type.

transect

A measured line or area along which ecological measurements (e.g. quadrats) are made.

tubers

Modified parts of a plant which are used to store food in the form of starch.

variegated

Having different colours e.g. a green and white leaf.