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Paper 2 Biological diversity > Biodiversity > Flashcards

Flashcards in Biodiversity Deck (22)
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1

Biodiversity definition

It's a measure of the variety of living organisms in a particular area.

2

Species biodiversity component

Species richness and species evenness

3

Species richness definition

Number of different species present in a particular area

4

Species evenness definition

A comparison of the number of individuals in each species present in a particular area

5

Genetic biodiversity

The variety of different genes that make up a species.

6

Habitat biodiversity

Number of different habitats found within an area

7

Random sampling

Selects individuals by chance, so that every individual has an equal chance of being chosen

8

Non-random sampling

- Opportunistic
- Stratified
- Systematic

9

Opportunistic sampling

- weakest form => biased data
- uses the conveniently available sample

10

Stratified sampling

- population is divided into strata based on particular characteristic (eg: gender)
- strata sampled separately in proportion to their part of the habitat as a whole

11

Systematic sampling

- samples are taken at fixed intervals
- line transect or belt transect can be used

12

Sampling animals techniques

- porter (small insects)
- sweep nets (insects in long grass)
- pitfall traps (crawling invertebrates)
- tree beating (invertebrates in trees)
- kick sampling (organisms in rivers)

13

Sampling plants techniques

- point quadrant
- frame quadrant

14

Measurements using the frame quadrant

percentage cover
density
frequency

15

Simpson's Index of Diversity

D= 1-(sum(n/N)^2)
0

16

Abiotic factors and associated sensors

pH - pH meter
light intensity - light meter
temperature - thermometer
oxygen content in water - dissolved oxygen probe
wind speed - anemometer
relative humidity - humidity sensor

17

Allele

Different version of the same gene

18

Importance of genetic biodiversity

If genetic biodiversity is high, there are more chances of survival of organisms because they are more likely to be able to adapt to changes in their environment due to the present of a higher number of different genes

19

Factors affecting genetic biodiversity

- mutations
- selective breeding
- interbreeding b/n different populations
- captive breeding (in zoos)
- rare breeds
- artificial cloning
- natural selection
- genetic bottlenecks (few individuals of a population survive an event or change)
- founder effect (when populations are geographically isolated)
- genetic drift (random nature of alleles being passed on from parents)

20

Polymorphism

proportion of polymorphic genes=number of polymorphic gene loci/total number of gene loci

21

Types of conservation

ex situ
in situ

22

Keystone species

Species that play an important role in maintaining the structure of an ecosystem