Module 4.2 - Biodiversity

Question 1

What is biodiversity?

Answer 1

The variety of living organisms in an area.

Question 2

What is the definition of a species?

Answer 2

A group of similar organisms able to reproduce to give fertile offspring.

Question 3

What is the definition of a habitat?

Answer 3

The area inhabited by a species. It includes the physical factors, like the soil and temperature change, and the living (biotic) factors, like availability of food or the presence of predators.

Question 4

What is habitat diversity and give an example?

Answer 4

The number of different habitats in an area. For example an area containing many different habitats such as sand dunes, woodland, meadows, streams etc.

Question 5

What is species diversity and give an example?

Answer 5

The number of different species (species richness) and the abundance of each species (species evenness) in an area. For example, a woodland could contain many different species of plants, insects, birds and mammals.

Question 6

What is genetic diversity and give an example?

Answer 6

The variation of alleles within a species (or a population of species). For example, the variation of alleles within the dog species gives rise to different breeds, such as a Labrador or poodle.

Question 7

Explain the process of sampling?

Answer 7

1) Choose an area to sample - a small area within the habitat being studied.
2) Count the number of individuals of each species.
3) Repeat the process - take as many samples as possible. This gives a better indication of the whole habitat.
4) Use the results to estimate the total number of individuals or the total number of different species in the habitat being studied.
5) When sampling different habitats and comparing them always use the same sampling technique.

Question 8

What device would you use for measuring/counting plants?

Answer 8

A quadrant (a frame which you place on the ground).

Question 9

What device would you use for measuring/counting both ground and flying insects?

Answer 9

> For flying insects you’d use a sweep net (a net on a pole).

>For ground insects you’d use a pitfall trap (a small pit that insects can’t get out of).

Question 10

What device would you use for measuring/counting aquatic animals?

Answer 10

You’d use a net.

Question 11

What type of sampling reduces bias?

Answer 11

Random.

Question 12

How do you make the sampling random?

Answer 12

For example, if you were looking at plant species in a field, you could pick random sample sites by dividing the field into a grid using measuring tapes and using a random number generator to select coordinates.

Question 13

Sometimes it’s necessary to take a non-random sample, what are the three types?

Answer 13

Systematic, opportunistic and stratified.

Question 14

Describe systematic sampling?

Answer 14

This is when samples are taken at fixed intervals, often along a line. E.g. quadrats could be placed along a line (called a transect) from an area of shade in the corner to the middle of the field.

Question 15

Describe opportunistic sampling?

Answer 15

This is when samples are chosen by the investigator. It’s used because it’s simple to carry out, but the data will be biased.

Question 16

Describe stratified sampling?

Answer 16

This is when different areas in a habitat are identified and sampled separately in proportion to their part of the habitat as a whole. E.g. a heathland may have patches of gorse in it - the heath and gorse areas would be sampled separately according to how much of each there was in the habitat.

Question 17

What are two things about species that increases biodiversity?

Answer 17

> Species richness.

>Species evenness.

Question 18

How is diversity measured?

Answer 18

Simpson’s Index of Diversity.

Question 19

What is the formula for Simpson’s index of diversity(D)?

Answer 19

D= 1 - (Σ (n/N)^2)  
n =  total number of individuals in one species.
N = total number of organisms of all species. 
Σ = 'Sum of' (added together).

Question 20

What does the value of Simpson’s index of diversity have to be between and what does this show?

Answer 20

Always a value between 0 and 1. The closer to 1 the index is, the more diverse the habitat. The greater the species richness and evenness the higher the number.

Question 21

What is dangerous about a population of organisms having low genetic diversity/variation?

Answer 21

The population may not be able to adapt to a change in the environment and the whole population could be sped out by a single event.

Question 22

Where is one place where genetic diversity may be low?

Answer 22

Isolated populations such as those bred in captivity.

Question 23

What is the equation you can use to measure genetic diversity in terms of polymorphic gene loci?

Answer 23

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

Question 24

What are three factors that are affecting global diversity ?

Answer 24

> Human population growth.
Increased use of monoculture in agriculture.
Climate change.

Question 25

Describe how human population growth growing massively in the past centuries is decreasing global diversity?

Answer 25

> Habitat loss
Over-exploitation
Urbanisation
Pollution

Question 26

Describe how habitat loss decreases biodiversity?

Answer 26

Human development is destroying habitats. E.g deforestation to make way for grazing and agriculture decreasing habitat diversity.

Question 27

Describe how over-exploitation decreases biodiversity?

Answer 27

A greater demand for resources (such as food, water, energy) means a lot of resources are being used up faster than can be replenished can decrease genetic diversity within populations as well as decreasing species diversity (extinction).

Question 28

Describe how urbanisation decreases biodiversity?

Answer 28

Large cities and major road developments can isolate species, meaning populations are unable to interbreed and genetic diversity is decreased.

Question 29

Describe how pollution decreases biodiversity?

Answer 29

High amounts of pollutants can kill species or destroy habitats habitats. E.g. high levels of fertiliser flowing into a river can lead to a decrease in fish species in that river - decrease in species diversity.

Question 30

What is agricultural monoculture?

Answer 30

The growing of a single variety of a single crop.

Question 31

Describe how an increase of use of monoculture in agriculture decreases global diversity?

Answer 31

> Habitats are lost as land is cleared to make way for large fields, reducing habitat diversity.
Local and naturally occurring plants and animals are seen as weeds and pests, and so are destroyed with pesticides and herbicides, reducing species diversity.
Heritage (traditional) varieties of crops are lost because they don’t make enough money and so are not planted any more, which reduces species diversity.

Question 32

How could a change in climate affect habitats and species diversity?

Answer 32

> Could make an area that was inhabitable become uninhabitable and this may cause an increase or decrease in the range of some species and this would affect the biodiversity.
Some species may be forced to migrate to a more suitable area causing a change in species distribution. Migrations usually decrease biodiversity where they leave from and increase where the go to.

Question 33

What happens to a species if there isn’t a suitable habitat for them to migrate to?

Answer 33

If the change is too fast, the species may become extinct and this will decrease biodiversity.

Question 34

What does organisms in an ecosystem being interdependent mean?

Answer 34

They depend on each other to survive.

Question 35

Describe two drastic effects to an ecosystem if a lost one species?

Answer 35

> Disruption of food chains.

>Disruption of nutrient cycles.

Question 36

Give an example of how the loss of one species in an ecosystem could disrupt nutrient cycles?

Answer 36

Decomposers like worms improve the quality of the soil by recycling nutrients. If worm numbers decline, soil quality will be affected. This will affect the growth of plants and the amount of food available to animals.

Question 37

What is a keystone species?

Answer 37

A species that many of the other species in the ecosystem depend on and without the ecosystem would change dramatically. They are often predators but can also be modifiers - maintaining the environment needed for the ecosystem.

Question 38

What do genetic resources (referring to any material containing genes) provide us with in terms of everyday products?

Answer 38

>Food and drink.
>Clothing.
>Drugs.
>Fuels
>Other industrial materials

Question 39

How are genetic resources important for the global economy?

Answer 39

Products derived from plant and animal species are traded on a local and global scale.

Question 40

What are the economic reasons for biodiversity?

Answer 40

To reduce soil depletion. Continuous monoculture involves planting the same crop in the same field without interruption but this causes soil depletion. This is because the nutrients required by the crop are gradually used up. The economic costs of soil depletion include increased spending on fertilisers and decreased yields.

Question 41

What are the aesthetic reasons for conserving biodiversity?

Answer 41

> Areas rich in biodiversity provide attractive landscapes.

>More visitors an area is likely to attract which has economic advantages.

Question 42

What does in situ conservation mean?

Answer 42

Keeping species in their natural habitat.

Question 43

Describe some methods of in situ conservation?

Answer 43

> Establishing protected areas such as national parks, wildlife preserves and marine conservation zones that restrict urban development, industrial development and farming (fishing controlled).
Controlling or preventing the introduction of species that threaten local diversity.
Protecting certain habitats.
Promoting particular species - could be protecting food sources or nesting sites for example.
Giving legal protection to endangered species.

Question 44

What is ex situ conservation?

Answer 44

Removing a species from their natural habitat.

Question 45

What are methods of ex situ conservation?

Answer 45

> Relocating an organism to a safer area.
Breeding organisms in captivity and then reintroducing them to the wild when they are strong enough.
Botanic gardens are controlled environments used to grow a variety of rare plants that could be reintroduced into suitable habitats.
Seed banks.

Question 46

What are the advantages and disadvantages of ex situ conservation?

Answer 46

Advantages -
>Protect individual organisms in a controlled environment, predation and hunting can be managed more easily.

Disadvantages -
>Only a small number of individuals can be cared for.
>It can be difficult and expensive to create and sustain the right environment.
>Might become used to human contact and less likely to exhibit natural behaviours or catch human diseases.
>Many can’t breed successfully in captivity.
>Less successful than in situ conservation.

Question 47

What are two examples of international cooperations that are important in species conservation?

Answer 47

> Rio Convention on Biological Diversity (CBD)

>CITES Agreement - (Convention on International Trade in Endangered Species).

Question 48

What does the CBD do?

Answer 48

> Develop international strategies on how to conserve biodiversity and how to use animal and plant resources in a sustainable way.
Made the conservation of biodiversity an international law and everyone’s responsibility.
Provides guidance to governments.

Question 49

What does the CITES Agreement provide?

Answer 49

> Regulates trade in wild animals and plant specimens.
The member countries all agreed to make it illegal to kill endangered species.
Raise awareness of threats to biodiversity through education.

Question 50

What does the Countryside Stewardship Scheme (CSS)?

Answer 50

> To improve and extend wildlife habitats by promoting specific management techniques to landowners.
Paid landowners who followed their suggested techniques.