Unit Two: Fossils and Extinction

Question 1

Name the ways which fossils are formed:

Answer 1

From gradual replacement by minerals
From casts abs impressions
From preservation in places where no decay happens

Question 2

Name six reasons as to why species can become extinct:

Answer 2

1. The environment changes too quickly
2. A new predator kills them all
3. A new disease kills them all
4. They can’t compete with another (new) species for food
5. A catastrophic event happens that kills them all
6. A new species develops (speciation)

Question 3

What is speciation?

Answer 3

The development of a new species

Question 4

What is isolation?

Answer 4

When populations of a species are separated due to physical barriers