Unit 4 - Biodiversity

Question 1

Define Succession

Answer 1

The progressive replacement of one dominant type of species or community by another in an ecosystem, until a stable climax community is established.

Question 2

Define intraspecific variation

Answer 2

The differences between organisms of the same species

Question 3

Define keystone species

Answer 3

Species which are essential for maintaining biodiversity-they have a disproportionately large effect on their environment relative to their abundance

Question 4

Define divergent evolution

Answer 4

Species diverge over time into two different species, resulting in a new species becoming less like the original one

Question 5

Define natural selection

Answer 5

The process by which organisms best suited to their environment survive and reproduce, passing on their characteristics to their offspring via their genes

Question 6

What is a line transect?

Answer 6

A line is marked along the ground between two points and samples are taken at specified points

Question 7

What is a belt transect?

Answer 7

Two parallel lines are marked and samples are taken of the area between the two lines

Question 8

Outline the process of mark-release-recapture

Answer 8

-organisms are captured and marked with a non-toxic marking
-time is allowed for organisms to redistribute
-the organisms are recaptured and the number of marked animals is compared to the number of unmarked animals

Question 9

Give 3 ways human have reduced biodiversity

Answer 9

-deforestation
-agriculture
-climate change

Question 10

Give 4 ways climate change will reduce biodiversity

Answer 10

-rising sea levels flood low lying land
-insect life cycles and population would change
-saltwater would flow further up rivers
-in some areas rainfall would lower