B18 - Organisms & their environment Flashcards
What are consumers? [1]
An organism that gets its energy by feeding on other organisms.
What is a trophic level? [1]
The position of an organism in a food chain and food web.
What are decomposers? [2]
Organisms that break down organic substances outside their bodies, releasing nutrients from them that other organisms can use.
What are producers? [1]
An organism that makes its own organic nutrients, generally using energy from sunlight, through photosynthesis.
What is a herbivore? [1]
An animal that gets its energy by eating plants.
What is a carnivore? [1]
An animal that gets its energy by eating other animals.
What is an omnivore? [1]
An animal that gets its energy by eating both animals and plants.
What is a primary consumer? [2]
- Herbivores
- They eat or consume the producers.
What is a secondary consumer? [2]
- Carnivores
- These consume the primary consumers.
What is a tertiary consumer? [3]
- These eat the secondary consumers (carnivores).
- These are hunters that hunt, catch, kill their prey for food
- Top of the food chain as they are not normally killed by other animals.
What is a quaternary consumer? [1]
- They feed on tertiary consumers.
Where does all the energy in a food chain originally come from? [1]
The Sun
What ALWAYS starts the food chain? [1]
Plants = the producer
What do organisms tend to do? [2]
- Increase in size
- Decrease in number
How do humans impact food chains? [2]
- Overharvesting food species e.g. overgrazing of grass
- Introducing foreign species to habitat e.g. cane toad in Australia.
What are the effects of overharvesting food species? [3]
- Decrease in biodiversity
- Risk of extinction of a species
- Disrupts natural food chain of habitat
What are the effects of introducing foreign species to habitat? [3]
- Disrupts natural food chain
- Loss of habitat as foreign species take over
- No natural predators to control population of species
