4.2- Biodiversity Flashcards Preview

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Flashcards in 4.2- Biodiversity Deck (49)
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1

What is the definition of biodiversity?

The variety of living organisms in an area

2

What is the definition of a species?

A group of similar organisms are able to reproduce to get fertile offspring

3

What is the definition of a habitat?

An area inhabited by species. It includes the abiotic factors and biotic factors

4

What are the three different levels of biodiversity can be considered on?

Habitat diversity
Species diversity
Genetic diversity

5

What is the definition of habitat diversity?

The number of different habitats in an area

6

What is the definition of species diversity?

The number of different species (species richness) and the abundance of each species (species evenness) in an area

7

What is the definition of genetic diversity?

The variation of alleles within a species

8

What are the different types of a non-random sampling?

Systematic
Opportunistic
Stratified

9

Why should samples be taken at random?

To avoid bias in your results

10

What is the definition of systematic sampling?

When samples are taken at fixed intervals

11

What is the definition of opportunistic sampling?

When samples are chosen by the investigator
It is simple to carry out but the data will be biased

12

What is the definition of stratified sampling?

When different areas in a habitat are identified and sampled separately in proportion to the habitat of a whole

13

Why is it sometimes necessary to take a non-random sample?

Eg. When there's lots of variety in the distribution and you want to make sure all the different areas are sampled

14

What is species richness?

The number of different species in an area

15

What is species evenness?

A measure of the relative abundance of each species in an area

16

If a habitat has a great species richness and a high species evenness, what will happen to the biodiversity?

It will be high

17

How is biodiversity measured?

Using the Simpsons index of diversity

18

What is the formula for the simpsons index of diversity?

D=1-(sum of(Total number of individuals of 1 species/Total number of organisms of all species)^2)

19

A habitat has a simpsons index of diversity equal to 0. What does this mean?

It is not very diverse

20

A habitat has a The Simpsons index of diversity equal to 1. What does this mean?

It is very diverse

21

What could occur if a population has a low genetic diversity?

They might not be able to adapt to change in the environment in the whole population could be wiped out buy disease

22

What does polymorphism describe?

A locus that has two or more alleles

23

What are the three main factors that affect global biodiversity?

Human population growth
Increased use of monoculture in agriculture
Climate change

24

How does human population growth decrease biodiversity?

Habitat loss
Overexploitation- greater demand for resources
Urbanisation can isolate species
Pollution can destroy habitats

25

How does increased use of monoculture in agriculture decrease biodiversity?

Habitat are lost as land is cleared
Plants destroyed with pesticides
Varieties of crops that don't make enough money and not planted anymore

26

How does climate change affect biodiversity?

A changing climate can increase or decrease the habitable areas of some species (this can increase or decrease biodiversity)
Species may be forced to migrate which shuffles biodiversity around (species can even go extinct)

27

Why is maintaining biodiversity important? (ecological reasons)

To protect species, including keystone species
To maintain genetic resources

28

Why is it important to protect species, including keystone species?

Organisms in an ecosystem are interdependent
The loss of just one species can cause disruption of food chains and disruption of the nutrient Cycle

29

What's a keystone species?

Species which many other species in an ecosystem depend on and without them, the system will change dramatically
They can be Predators modifiers or hosts

30

Why is it important to maintain genetic resources?

Genetic resources provide us with a variety of everyday products such as food, clothes, industrial materials and drugs