9A — Genetics and Evolution

Question 1

What are species?

Answer 1

A species is a group of organisms that are able to reproduce to give offspring that are also able to reproduce.

Question 2

What is environmental variation?

Answer 2

Environmental variation is when characteristics vary due to environmental factors in an organism’s surroundings (its environment).

Question 3

What is inherited variation?

Answer 3

Inherited variation is when offspring inherit characteristics from their parents and these characteristics can vary (e.g. brown eyes and blue eyes).

Question 4

1) What is DNA?

2) What is a chromosome?

Answer 4

1) DNA contains code which is an organism’s genetic information and gives organisms their characteristics.
2) A chromosome contains a long molecule of DNA. Certain sections of that DNA molecule contain the genetic information and are called genes.

Question 5

What is adaptation?

Answer 5

Adaptation is when an organism has characteristics that allow them to survive in that habitat.

Question 6

What is natural selection?

Answer 6

A process in which an organism is more likely to survive and reproduce than other members of the species because it possesses a certain inherited variation.

Question 7

How is endangerment or extinction caused?

Answer 7

● changes in physical environmental factors
● competition from other organisms
● disease
● human activities (e.g. hunting, clearing habitats, using poisons)

Question 8

How can biodiversity be preserved?

Answer 8

● protecting areas and setting up nature reserves
● setting up breeding programmes in zoos
● banning the hunting of some animals or the collecting of wild plants
● setting up gene banks (to store parts of organisms, such as seeds and gametes).

Question 9

Why should biodiversity be preserved?

Answer 9

● organisms depend on one another (they are interdependent)
● we won’t be able to make use of organisms if they become extinct
● more biodiverse areas recover better from natural disasters