Biodiversity

Question 1

What is meant by biodiveristy?

Answer 1

the variety of living organisms present in an area

Question 2

What are the 3 different ways in which biodiversity can be studied?

Answer 2

• habitat biodiversity
• species biodiversity
• genetic biodiversity

Question 3

What is species richness?

Answer 3

the number of different species living in a particular area

Question 4

What is species evenness?

Answer 4

a comparison of individuals in each species in a community

Question 5

What is meant by genetic biodiversity?

Answer 5

refers to the variety of genes that make up a species

Question 6

What is sampling?

Answer 6

means taking measurements of a limited number of individuals in a certain area

Question 7

What is the method for random sampling?

Answer 7

select individuals by chance:
- mark out a grid on the area, use a random no. generator to determine the x and y co-ordinates
- take a sample from the co-ordinates generated

Question 8

What is opportunistic sampling?

Answer 8

(not representative of population) use organisms that are conveniently available

Question 9

What is stratified sampling?

Answer 9

population divided into strata (sub-groups) based on particular characteristic (e.g. separating males and females)

Question 10

What is systematic sampling?

Answer 10

diff areas within an overall habitat are identified, which are then samples separately
- line transect
- belt transect (sample taken from between the two lines)

Question 11

What are the techniques used for sampling animals?

Answer 11

-pooter (used to catch small insects)
- sweep nets
- pitfall traps (trap small animals)
- tree beating

Question 12

How does a point quadrat work?

Answer 12

frame with horizontal bar, push pins in at different intervals

record each species of plant in the pin touches

Question 13

How does a frame quadrat work?

Answer 13

consists of a square frame, divided into equal sections
the type and number of each species within the sections is recorded

Question 14

How do you collect the most valid representative sample?

Answer 14

quadrats, with random sampling technique

Question 15

How can frame quadrats be used to sample a population of plants living in a habitat?

Answer 15

density

frequency

percentage cover

Question 16

What are the six abiotic factors?

Answer 16

wind speed
light intensity
relative humidity
pH
temperature
o2 content in water

Question 17

How is biodiversity calculated?

Answer 17

Using Simpson’s Index

D = 1 - total (total number of organisms of all species / total number of organisms in particular species)

Question 18

What do the results of a Simpson’s index mean?

Answer 18

1 = infinite biodiversity
0 = no biodiversity

Question 19

What are the factors that affect genetic biodiversity?

Answer 19

INCEASE:
1. mutations
2. interbreeding between different populations (alleles transferred known as gene flow)
DECREASE:
1. Selective breeding
2. rare breeding
3. natural selection
4. genetic bottlenecks
5. founder effect

Question 20

What is meant by genetic bottleneck?

Answer 20

where only few individuals survive an event or change, reduces gene pool for further populations

Question 21

What is meant by the founder effect?

Answer 21

where a small number of individuals create a new colony, geographically isolated

Question 22

What are the three human influences on biodiversity?

Answer 22

1. deforestation
2. agriculture
3. climate change

Question 23

What are the aesthetic reasons for maintaining biodiversity?