Chapter 11 - Biodiversity

Question 1

Why is biodiversity important?

Answer 1

Essential to maintaining a balanced ecosystem. All species are interconnected and interdependent, all rely on one another.

Question 2

What are the 3 levels of measuring biodiversity?

Answer 2

Habitat biodiversity

Species Biodiversity

Genetic Biodiversity

Question 3

What is habitat biodiversity?

Answer 3

The number of different habitats within a given area.

Question 4

What is species biodiversity?

Answer 4

2 components;

Species Richness - number of different species living within an area

Species Evenness - a comparison of the numbers of individuals of each species living within a community.

Question 5

What is genetic biodiversity?

Answer 5

Refers to the variety of genes that make up a species. Can lead to differing bc characteristics.

Question 6

What is sampling?

Answer 6

Taking measurements of a limited number of individual organisms present in a particular area. Can be used as ab estimation.

Question 7

What is random sampling?

Answer 7

Selecting individuals by chance. There is an equal likelihood for whatever organism to be chosen.

Question 8

How to carry out random sampling?

Answer 8

Mark out a grid on the grass using 2 tape measures laid at right angles

Use a random number generator to determine the x coordinate and the y coordinate on the grid.

Take a sample at the coordinates generated.

Repeat

Question 9

What are the 3 non random sampling methods?

Answer 9

Opportunistic

Stratified

Systematic

Question 10

Disadvantages of opportunistic sampling?

Answer 10

May not be representative as it uses organisms that are conventiently available.

Question 11

What is stratified sampling, how can it be carried out?

Answer 11

Divided into subgroups (strata) based on particular characteristics. Eg separated into males and females. A random sample is then taken from each strata proportional to its size

Question 12

How can systematic sampling be carried out?

Answer 12

Different areas within an overall habitat are identified and they’re sampled separately. Nah be used to see how plant species change as you move away from the sea

Often carried out using a line or belt transect

Question 13

Why so sampling never fully reliable?

Answer 13

Sampling Bias- can be reduced by choosing random sampling.

Chance - where the organisms selected may not be representative of the whole area. Can be reduced by using a larger sample size.

Question 14

What is a pooter used for?

Answer 14

Catching small insects, sucking on a mouth piece means that insects are picked up and held in a holding tube

Question 15

What are sweep nets used for?

Answer 15

Used to catch insects in areas of long grass

Question 16

What are pitfall traps used for?

Answer 16

Used to catch small crawling invertebrates such as beetles, spiders and slugs. A hole is dug into the ground and the insects fall into it

Question 17

What is tree beating used for?

Answer 17

Used to take samples of invertebrates living in a tree or Bush. Large white cloth stretched out under the tree. Tree is shaken, insects fall onto sheet where they can be studied.

Question 18

What is kick sampling?

Answer 18

Used to study organisms living in a river. River bank / bed is kicked for a short period of time to dislodge the substrate. A net is held downstream for a period of time to capture any organisms released into the flowing water.

Question 19

What are plants normally sampled with?

Answer 19

Quadrat

Question 20

What are the 2 types of quadrat?

Answer 20

Point quadrat and frame quadrat.

Question 21

How can you measure species richness?

Answer 21

Using a variety of techniques. A list of species should be compiled and a total number of species can then be calculated.

Question 22

3 ways to estimate population when using frame quadrats?

Answer 22

Density

Frequency

Percentage Cover

Question 23

How can population be estimated?

Answer 23

Using a capture-mark-release-recapture method

Question 24

Why is maintaining biodiversity important?

Answer 24

Ecological reasons

Economic reasons

Aesthetic reasons (eg protecting landscapes)

Question 25

What are in situ ways of maintaining biodiversity?

Answer 25

Marine conservation zones

Wildlife reserves

Question 26

What are ex situ ways of maintaining biodiversity?

Answer 26

Zoos, seed banks, and botanic gardens

Captive breeding programmes