Extinction

Question 1

Define extinction

Answer 1

The permanent loss of all members of one species. It always involves a change in the environment of an organism.

Question 2

Define Mass Extinction

Answer 2

**The loss of many species on Earth, often taking over several million years to occur. **
So far, there have been five mass extinction events and this can be shown by 5 major peaks in a graph.
A single catastrophic event is the most common cause of mass extinction.

Question 3

State the abiotic (non-living) factors that can contribute to the extinction of a species.

Answer 3

1. Extreme changes in climate
2. Single catastrophic events which also affected climate e.g. asteroids colliding with earth or volcanoes, earthquakes, droughts and floods.

Question 4

Why does extinction occur?

Answer 4

Changes are too fast for the organisms to have time to adapt (for evolution to occur)

Question 5

State the biotic (living) factors that can lead to the extinction of a species.

Answer 5

1. New predators (including hunting by humans)
2. New communicable diseases- particularly if the entire population is located in one area
3. Competition from a new species for food
4. Shortage of food- prey runs out