National 5 Biology | Unit 3 - Life on Earth

Niche

The role of an organism in its habitat

Habitat

Place where an organism lives

Ecosystem

An environment consisting of all the living and non living things

Population

All the members of one species in a particular area

Biodiversity

The number of different species in an area

Community

Organisms in an ecosystem.

Producer

An organism that makes its own food

Predator

An animal that hunts other animals for food

Prey

Animal hunted or caught for food

primary consumer

An organism that eats producers

secondary consumer

An organism that eats primary consumers

Food chain

A diagram showing how energy passes from one organism to the next in an ecosystem

Food web

A diagram that shows the relationships between different food chains

apex predator

an organism at the top of the food chain that no other organism eats for food

Biome

an area on Earth that shares the same climate and species of animals and plants.

Flora

Plants

Fauna

Animals

interspecific competition

competition between different species

intraspecific competition

competition within a species

Photosynthesis

Conversion of light energy from the sun into chemical energy.

light reactions

chlorophyll molecules absorb energy from sunlight and use that energy to split water into hydrogen and oxygen

carbon fixation

The combination of carbon dioxide with hydrogen using ATP to produce glucose

ATP

adenosine triphosphate

Species

A group of similar organisms that can breed and produce fertile offspring.

Speciation

Formation of new species

biotic factor

a living factor that affects biodiversity

abiotic factor

a non-living factor that affects biodiversity

Pitfall traps

A hole dug to catch some species for sampling using a pot and a raised lid

Quadrat

A square frame used for sampling plant numbers

Transect Line

Measuring plant species along a line across a habitat at regular intervals

Paired Statement Key

A key used to identify a living organism

Indicator Species

A species that, depending on the presence or absence can identify levels of pollution

Fertilisers

Substances that are absorbed by plants to produce proteins and increase plant growth

Pesticides

Chemicals that kill pests to increase crop yield

Biological Control

The introduction of a predator that preys on pests in order to increase crop yield

90%

percentage of energy lost at each stage of the food chain

pyramid of numbers

shows the number of organisms at each stage of the food chain

pyramid of energy

shows how much energy is passed on at each stage of the food chain

mutation

a random change in an organism's DNA

variation

the difference between organisms in a species

Adaptation

A change in the body to suit environmental conditions and helps the organism to survive

Advantageous mutation

A mutation that benefits the organism like the peppered moth

Neutral Mutation

A mutation that is not advantageous or disadvantageous like a change in eye colour

Disadvantageous Mutation

A mutation that does not benefit the organism like cystic fibrosis

Natural Selection

The strongest and best adapted organisms survive to reproduce and pass on their favorable genes

Isolation barrier

A barrier that separates two sub species during speciation that can be geographical, ecological and behavioral

Leaching

When fertilisers run into reservoirs resulting in algal bloom

Algal Bloom

When algae grows on the surface of the water so plants die because of lack of sunlight, then microbes use oxygen resulting in animals dying from lack of oxygen

Bioaccumulation

the build up of substances, such as pesticides, over a food chain

Deforestation

A decrease in biodiversity by destroying habitats

Desertification

A decrease in biodiversity by turning land into desert and sterilizing soil

Pollution

A decrease in biodiversity by polluting land and water with substances like oil and waste

Overfishing

A decrease in biodiversity by taking more fish that needed and killing a species' population

Conservation

An increase in biodiversity by helping animals breed in captivity in a safe environment

Branching Key

A key used to identify an organism by following instructions