Biodiversity

Question 1

Definition of biodiversity

Answer 1

The variety of living organisms in an area

Question 2

Definition of species

Answer 2

A groups of similar organisms able to reproduce to give fertile offspring

Question 3

Definition of habitat

Answer 3

The area inhabited by a species. It includes abiotic factors eg soil and temp range and the biotic factors eg presence of predators.

Question 4

Definition of habitat diversity

Answer 4

The number of different habitats in an area. Eg a woodland could contain many habitats

Question 5

Definition of species diversity

Answer 5

The number of different species and the abundance of each species in an area.

Question 6

Definition if genetic diversity

Answer 6

The variation of alleles within a species

Question 7

How to sample for biodiversity

Answer 7

1) choose an area to sample - a small area within the habitat
2) count the number of individuals of each species
3) repeat the process -take as many samples as possible
4) use results to estimate the number of individuals/ species in the habitat being studied
5) when sampling different habitats and comparing them, always use the same sampling technique

Question 8

Different Organisms and their sampling techniques

Answer 8

Crawling ground insects - pitfall trap or pooters
Small organism in soil/ leaves - Tullgren funnel
Aquatic organisms - kick sampling
Organisms in long grass - sweep net

Question 9

How to carry out a random sample

Answer 9

1) divide the field into a grid using measuring tapes
2) use a random number generator to select coordinates

Question 10

Three types of non-random sampling

Answer 10

1) systematic
2) opportunistic
3) stratified

Question 11

What is systematic sampling

Answer 11

-when you take samples at fixed intervals , often along a line.

Question 12

What is opportunistic sampling

Answer 12

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

Question 13

What is stratified sampling

Answer 13

This is where different areas in a habitat are identified and sampled separately in proportion to their part of the habitat As a whole.

Question 14

What is species richness

Answer 14

This is the number of different species in an area. The higher the number of species , the greater the species richness. Measured using random samples and counting the number of different species

Question 15

What is species eveness

Answer 15

A measure of the relative abundance of each species in an area. The more similar the population size of each species, the greater the species eveness. Measured by taking random samples of a habitat and counting the number of individuals of each species.

Question 16

What is diversity measured using

Answer 16

Simpson’s index of biodiversity

Question 17

What is Simpson’s index

Answer 17

Takes into account both species eveness and richness. Value is always been 0 and 1. The closer to 1 it is, the more diverse the habitat.

D= 1- (sum of (total number of individuals of one species/ total number of organisms of all species)2)

Question 18

Why is it important to assess genetic diversity

Answer 18

It is important because if a population has low genetic diversity, they might not be able to adapt to a change in environment and the whole population could be wiped out. Eg Breeding programmes in zoos are very closely managed to maximise genetic diversity.

Question 19

What’s is genetic polymorphism

Answer 19

Describes when a locus has two or more alleles. Working out the proportion of genetic gene loci gives you a measure of genetic diversity.

Question 20

Formula to work out proportion of polymorphic gene loci

Answer 20

Number of polymorphic gene loci/ total number of loci

Question 21

Factors affecting global biodiversity

Answer 21

1) human population growth
2) increased use of monoculture in agriculture
3) climate change

Question 22

How has human population growth affected biodiversity

Answer 22

1) habitat loss- human development destroys habitats to make space for agriculture and grazing

2) over exploitation- a greater demand for resources means resources are being used up faster than they are being replenished (eg overfishing)

3) urbanisation - road developments and sprawling cities can isolate species meaning many populations cannot interbreed and genetic biodiversity decreases.

4) pollution - high amounts of pollutants can kill species or destroy habitats eg High levels of fertiliser flowing into a river can decrease fish species in that river.

Question 23

How does increased use of monoculture in agriculture affect biodiversity

Answer 23

1) habitats are lost as land is cleared to make way for large fields

2) local and naturally occuring plants and animals (weeds/pests) are destroyed using pesticides snd herbicides

3) heritage varieties of crops are lost because they dont make enough money and no longer planted.

Question 24

How does climate change affect biodiveristy

Answer 24

Most species need a particular climate to survive. A change in climste means that an area that was previously inhabitable becomes uninhabitable (and vice versa) .This may cause an increase/ decrease in range of some species.

Some species may be forces to migrate to a more suitable area, causing a chnage in species disribution. Migration usually decreases biodiveristy from where the species migrated from, and increases biodiveristy to where they migrate to.

If there isnt a suitabke habitat to migrate to, the species is a plant and cant migrate, or if the change is too fast, the species may become extinct.

Question 25

Why is maintaining biodiversity important for ecological reasons -1

Answer 25

1) to protect keystone species. Organisms in an ecosystem are interdependent so if one species is lost, it can have a drastic effect on the entire ecosystem.

• it can disrupt food chains as if the primary consumer population declines, it decreases the population of the secondary and therefore tertiary consumer.

-disruption of nutrient cycles eg is decomposers decline, then soil quality declines and less plants available for animals.

Question 26

What is a keystone species

Answer 26

Species on which many other species in an ecosystem depend on and without them, the ecosystem would change dramatically. Keystone species are usually predators- keeping the population of prey in check.

Question 27

Why is maintaining biodiversity important for ecological reasons -2

Answer 27

2) to maintain genetic resources . Genetic resources is any material from plants, animals or microorganisms contains genes that we find valuable.

Food and drink - plants and animals are the source of almost all food and drink

Clothing - a lot of fibres and fabrics are made from plants and animals.

Drugs - many are made from plant compounds (morphine made from poppies)

Fuels - we use a number of different organisms to produce renewable fuels including ethanol

Other industrial materials - many materials produced from plants and animals eg wood, paper, dyes, adhesives, oil rubber and pesticides.
These are important for global economy as products made from plants and animals are traded on local and global scale.

Question 28

Why is maintaining biodiversity important for economic reasons

Answer 28

This is to reduce soil depletion
Monoculture is growing a single variety of a single crop. Continuous monoculture leads to soil depletion 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 29

Why is maintaining biodiversity important for aesthetic reasons

Answer 29

1) areas rich in biodiveristy provide pleasant, attractive landscapes that people enjoy. By maintaining biodiveristy, we maintain the beautiful landscapes.

2) the more biodiversity in an area, the more visitors the area is likely to attract, this also has economic advantages.

Question 30

What is in situ conservation

Answer 30

This means protecting species in their natural habitat.

Question 31

Methods of in situ conservation

Answer 31

1) establishing protected areas eg national parks and wildlife reserves. Habitats and species in these areas are protected by restricting urban development, industrial development and farming. This occurs in marine conservation zones where human activities (fishing) are controlled.

2) controlling or preventing the introduction of species that threaten local biodiveristy. Eg Grey squirrels compete with red squirrels and have caused population decline so they’re controlled.

3) protecting habitats eg controlling water levels to conserve wetlands and coppicing to conserve woodlands.

4) promoting particular species - this could be by protecting Food sources of nesting sites.

5) giving legal protection to endangered species eg making it illegal to kill them

Question 32

What is ex situ conservation

Answer 32

This means removing an organism from a threaten habitat to a new location

Question 33

Methods of ex situ conservation

Answer 33

1) relocating to a safer area
2) breeding organisms in captivity then reintroducing into the wild when they are strong enough
3) botanic gardens are controlled environments to grow a variety of rare plants for the purposes of conservation, research, display and education.
4) seed banks- seeds are frozen and stored in seed banks so that is natural reserves are destroyed , the plant species can be reintroduced.

Question 34

What are the two international conservation agreements

Answer 34

1) Rio convention of biological diversity (CBD)
2) CITES agreement ( convention on international trade in endangered species)

Question 35

What is the Rio convention on biological diversity (CBD)

Answer 35

1) it aims to develop international strategies on the conservation of biodiversity and how to use animal and plant resources in a sustainable way.

2) the convention made it part of international law that conserving biodiveristy is everyone’s responsibility .

3) it also provides guidance to governments in how to conserve biodiversity.

Question 36

What is the CITES agreement

Answer 36

1) it is an agreement designed to increase international cooperation in regulating trade in wild animals and plant specimens.

2) the member countries all agreed to make it illegal to kill endangered species

3) the agreement helps to conserve species by limiting trade through licensing and by making it illegal to trade in products made from endangered animals .

4) also designed to raise awareness of threats to biodiveristy through education.