WJEC Biology Predator and Prey Populations!

WJEC Biology – Predator and prey populations! All living things within an ecosystem are interdependent. A change in the size of one population affects all other organisms within the ecosystem. This is shown particularly clearly by the relationship between predator and prey populations. There is a continuous tussle between predators and their prey. Predator species need to be adapted for efficient hunting if they are to catch enough food to survive. Prey species, on the other hand, must be well adapted to escape their predators, if enough of them are to survive for the species to continue. If the prey population in an ecosystem grows, predator numbers will respond to the increased food supply by increasing as well. Growing predator numbers will eventually reduce the food supply to the point where it can no longer sustain the predator population ... and so on.

1. There are many abiotic and biotic factors that can limit populations in ecosystems.

2. Abiotic factors include natural disturbances or environmental conditions such as temperature.

A. A forest fire can greatly reduce a population. B. Trees do not grow high up on mountains where it is too cold. C. Changes in weather patterns, such as global warming, can have a negative impact on population sizes.

3. Biotic factors include predator-prey cycles, parasites, diseases, A. A large number of predators can limit the number of prey. However, once the prey drops, the number of predators will also decrease. B. Parasites like the pine beetle limit the population of pine trees. C. Diseases can cause a population to decrease. D. Individuals can compete with each other for limited resources. When there is not enough to go around, populations are limited.

4. Human activity can be a limiting factor for species, especially when pollution is created or habitat is taken away. WJEC Biology – Predator and prey populations! All living things within an e are I . A change in the size of one p affects all other o within the e . This is shown particularly clearly by the relationship between p and p populations. There is a continuous tussle between predators and their prey. P species need to be a for efficient hunting if they are to catch enough food to s . P species, on the other hand, must be well a to escape their p , if enough of them are to survive for the species to continue. If the p population in an e grows, p numbers will respond to the increased food supply by increasing as well. Growing p numbers will eventually reduce the food supply to the point where it can no longer sustain the p population ... and so on.

1. There are many abiotic and biotic factors that can limit populations in ecosystems.

2. A factors include natural disturbances or environmental conditions such as temperature.

A. A forest fire can greatly reduce a p . B. Trees do not grow high up on mountains where it is too cold. C. Changes in weather patterns, such as global warming, can have a negative impact on p sizes.

3. B factors include predator-prey cycles, parasites, diseases, A. A large number of p can limit the number of prey. However, once the prey drops, the number of predators will also decrease. B. Parasites like the pine beetle limit the population of pine trees. C. D can cause a population to decrease. D. Individuals can c with each other for limited resources. When there is not enough to go around, populations are limited.

4. Human activity can be a l factor for species, especially when p is created or h is taken away.