Levels of organisation Flashcards – AQA GCSE Biology - Foundation (8461)

What does a food chain represent?

A sequence of energy transfers between organisms through feeding.

How are organisms arranged in a food chain?

A producer comes first, followed by consumers that feed on the preceding organisms.

What direction do arrows point in a food chain?

From the organism being eaten to the organism receiving energy.

What are a predator and its prey?

A predator is a consumer that kills and eats another animal; the animal eaten is its prey.

Why can a predator population increase when prey become more abundant?

More prey provides more food for predators.

How can an increase in predation affect prey numbers?

It can contribute to a decline in the prey population.

Why may predator numbers fall when prey become less abundant?

Less prey is available as food.

How can a fall in predator numbers allow prey to recover?

Reduced predation allows the prey population to recover.

What features of a population graph can be used to compare predator and prey populations over time?

Their values, rises, falls, peaks and troughs.

Why do predator population peaks typically follow prey population peaks?

The predator population takes time to respond to changes in prey availability.

How do photosynthetic organisms make glucose, and what else is released?

They use light energy to make glucose from carbon dioxide and water, releasing oxygen.

What is an organism's biomass?

The mass of its living material.

How does glucose contribute to a photosynthetic organism's biomass?

It provides material for making other organic molecules that contribute to biomass.

Why are green plants and algae called producers?

They make organic material rather than obtaining it by eating other organisms.

How does the biomass of producers support other organisms?

It supplies organic material to consumers through feeding relationships.