4.3 explain how quadrats can be used to sample the distribution of organisms in their habitats

This experiment is laid out along a line (known as a transect).

-  Mark out a line along the area you want to investigate

- Using quadrat(s) placed next to each other, collect data along the line.

That's it :)

4.2 explain how quadrats can be used to estimate the population size of an organism in two different areas

Firstly, this is a quadrat…

They are usually 1m2 and split up into 100 smaller squares. Just randomly place/throw it on the ground and count all of the organisms within the quadrat. Repeat 5 times and find the mean. Now multiply the number of that organism found with the size (in m2) of the area you are investigating.

Repeat with another area and compare.

4.1 understand the terms population, community, habitat and ecosystem

Population - All the organisms of one species in a habitat

Community - All the different species in a habitat

Habitat - The area/place in which an organism lives

Ecosystem - All of the organisms living in a particular area and all the abiotic (non-living) conditions

NOTE: You literally just need to learn these