Ecosystems
What is a population?
A group of organisms of the same species.
What tool is used to count organisms in a small area?
Quadrat.
What does an arrow show in a food chain?
Direction of energy transfer.
What is a biotic factor?
A living factor that affects a community.
What do animals compete for?
Food, space, and mates.
What is a community?
Different populations living together and depending on each other.
What is random sampling used for?
To estimate the size of a population.
What is a producer?
An organism (usually a plant) that makes its own food using photosynthesis.
What is an abiotic factor?
A non-living factor that affects a community.
What do plants compete for?
Light, water, minerals, and space.
What makes an ecosystem different from a community?
An ecosystem includes both the community and the non-living (abiotic) environment, while a community is only living organisms.
What is systematic sampling?
Sampling at regular intervals to see how organisms are distributed
What is the difference between primary and secondary consumers?
Primary consumers eat producers; secondary consumers eat primary consumers.
Give one example of each type of factor.
Biotic: predators; Abiotic: temperature (or light/water).
Why do organisms compete in an ecosystem?
Because resources are limited.
Give an example of an ecosystem and identify one biotic and one abiotic factor in it.
Example: rainforest – biotic: plants/animals, abiotic: sunlight/water.
Describe how a transect is used in sampling.
A transect line is laid across an area and quadrats are placed at intervals to record organisms.
Predict what happens if a prey population decreases.
Predator numbers may decrease due to less food.
Describe how one abiotic factor can affect organisms.
Example: low temperature can reduce survival or reproduction.
Describe how competition can affect population size.
Strong competitors survive and increase; weaker ones decrease.
Explain how different populations depend on each other within a community.
Populations depend on each other for food and survival (e.g. predators rely on prey, plants support herbivores).
Explain why a transect is useful when investigating how a factor affects organism distribution.
It shows how a factor (e.g. distance from water) affects where organisms are found.
Explain how removing one species could affect multiple populations in a food web.
Removing a species can affect many others by disrupting feeding relationships across the web.
Explain how biotic and abiotic factors together influence where organisms can live.
Abiotic factors set conditions, and biotic factors (like predators/competition) further affect survival and distribution.
Explain why the best competitors are more likely to survive and reproduce.
They are more likely to survive, reproduce, and pass on their genes.