Organisms

Question 1

Name five physical factors which may affect organisms.

Answer 1

Temperature
Amount of light
Availability of water
Availability of nutrients
Availability of oxygen and carbon dioxide
(These do not include factors such as the presence or absence of predators.)

Question 2

What is an environment?

Answer 2

All the conditions that surround a living organism

Question 3

What is a habitat?

Answer 3

The place where an organism lives

Question 4

What does population mean?

Answer 4

All the members of a single species that live in a habitat

Question 5

What is a community?

Answer 5

All the populations of different organisms that live together in a habitat

Question 6

What is an ecosystem?

Answer 6

A community and the habitat in which it lives.

Question 7

What can you use to sample a population of a particular organism?

Answer 7

Transects and quadrats

Question 8

What is a transect?

Answer 8

A transect is a line across a habitat or part of a habitat. It can be as simple as a string or rope placed in a line on the ground.

Question 9

How can a transect be used to record information?

Answer 9

The number of organisms of each species can be observed or recorded at regular intervals along the transect

Question 10

What is a quadrat?

Answer 10

A quadrat is usually a square made of wire. It may contain further wires to mark off smaller areas inside, such as 5 x 5 or 10 x 10 squares.

Question 11

What should you do when using a quadrat?

Answer 11

The quadrat should be placed randomly so that a representative sample is taken
The validity and reproducibility of the results from more quadrats are analysed.