4.2.1 - Biodiversity

Question 1

What is biodiversity?

Answer 1

A measure of the variation found in the living world

Question 2

What are the 3 levels at which biodiversity can be considered?

Answer 2

• Habitat
• Species
• Genetic

Question 3

What does species diversity mean?

Answer 3

The number of different species and individuals within each species in a community

Question 4

What does species richness mean?

Answer 4

The number of different species in a particular area at the particular time

Question 5

What does species evenness mean?

Answer 5

The number of individuals of each species in a habitat

Question 6

What does genetic diversity mean?

Answer 6

The variety of genes amongst all the individuals in a population of one species

Question 7

What does habitat diversity mean?

Answer 7

The range of different habitats

Question 8

How do you ensure your sample is representative of the population?

Answer 8

• Take a large sample
• Randomly sample to avoid bias

Question 9

How could you carry out random sampling?

Answer 9

• Lay out 2 tape measures at right angles to each other to create a gridded area
• Use a random number generator to generate 2 numbers to serve as coordinates on the grid
• Place your quadrat at the coordinates and record the data

Question 10

What are the 3 non-random sampling techniques?

Answer 10

• Opportunistic
• Stratified
• Systematic

Question 11

What is opportunistic sampling?

Answer 11

Sampling organisms which are conveniently available or have been selected deliberately by the researcher. This is often inaccurate as it involves bias.

Question 12

What is stratified sampling?

Answer 12

Where samples are taken in proportion to the size of each population

Question 13

What is systematic sampling?

Answer 13

Where samples are taken at regular intervals usually involving a belt transect. This is used when there is a change in the distribution of species within the habitat.

Question 14

What is a quadrat used for?

Answer 14

Used to sample plants and slow moving organisms

Question 15

What are sweeping nets?

Answer 15

Nets that are used to collect invertebrates in low-growing vegetation

Question 16

What are pitfall traps?

Answer 16

A hole is dug in the ground and a pot is placed in it so small invertebrates that are found on the soil surface or leaf litter fall into it and will be unable to crawl out. A roof like structure is placed on top to prevent the trap filling with rainwater.

Question 17

What are pooters?

Answer 17

Two tubes are connected to a closed pot. The investigator sucks on one tube and places the other tube over the insect which creates suction and draws the insect into the pot. Used to collect insects found in crevices or in sweep nets.

Question 18

What is a Tullgren funnel?

Answer 18

The soil sample is dried using a heat lamp and this causes the animals to move in the opposite direction downwards where a collecting dish is placed. Used to collect small invertebrates from soil and leaf litter.

Question 19

What is kick sampling?

Answer 19

One researcher gently kicks the river bed to disturb the organisms within it while another researcher stands behind them with a net to capture any organisms that are released. Used to dislodge freshwater invertebrates on stream beds.

Question 20

How would you measure species richness?

Answer 20

Estimate using a qualitative study - observe and record the different species found in the habitat

Question 21

How would you measure species evenness?

Answer 21

Requires a quantitative study:
- for plants count individuals of each species or percentage cover
- for animals count directly or estimate population size using mark-recapture technique

Question 22

How can you calculate genetic diversity?

Answer 22

By examining polymorphic genes within isolated populations such as zoos, rare breeds and pedigree animals where selective breeding has been used.

Question 23

What is a polymorphic gene?

Answer 23

A gene that has more than one allele

Question 24

What is gene that has one allele called?

Answer 24

Monomorphic gene

Question 25

What does a higher proportion of polymorphic gene loci mean?

Answer 25

The larger the genetic diversity within the population

Question 26

What are the 3 factors affecting biodiversity?

Answer 26

- Human population - Agriculture - Climate change

Question 27

How does human population affect biodiversity?

Answer 27

- Increasing at an exponential rate - Means there is an increased need for space for housing, farming and industry which requires deforestation

Question 28

How does agriculture affect biodiversity?

Answer 28

- Increased agriculture to feed everyone - Clearing land for agriculture results in the destruction of habitats - Chemical pesticides or fertilisers may be added to the land and monocultures may be grown - This reduces the number of habitats and range of food sources

Question 29

How does climate change affect biodiversity?

Answer 29

- Increase in global temperatures is melting polar ice caps which destroys habitats and causes sea levels to rise which is reducing biodiversity due to flooding - The higher global temperatures and lower rainfall means some plants and animals are unable to survive and xerophytes are becoming the dominant species in some areas with these plants outcompeting others as they can survive in harsher abiotic conditions

Question 30

What are the 3 reasons for maintaining biodiversity?

Answer 30

- Ecological - Economic - Aesthetic

Question 31

What are the ecological reasons for maintaining biodiversity?

Answer 31

- The loss of one species impacts all others as they are all interdependent on each other - For example, the removal of a habitat removes food sources for many animals - Conservation measures to protect these habitats must be put in place but not to an extent that farming is no longer possible and humans run out of food

Question 32

What are the economic reasons for maintaining biodiversity?

Answer 32

- Deforestation can result in soil erosion and monocultures can result in soil becoming deficient in particular minerals that the crop absorbs a lot of - Both results in soil depletion and can negatively impact a country's ability to grow crops - Tourism often relies on people visiting areas of natural beauty and observing animals in their natural habitat so extinction of habitats, plants and animals could reduce tourism impacting the economy - Many medicines have been based on chemicals naturally occurring in plants so plant species going extinct could have potentially held the molecules needed to cure diseases in humans

Question 33

What are the aesthetic reasons for maintaining biodiversity?

Answer 33

- Being in nature around animals and plants enriches people's lives and has been shown to improve people's mental health which is why people may choose to visit different environments like the rainforest and beaches - Nature is also a creative inspiration for art, music and writers

Question 34

What does in situ mean?

Answer 34

Within the natural habitat

Question 35

What does ex situ mean?

Answer 35

Not within the natural habitat

Question 36

What are 2 examples of in situ methods of maintaining biodiversity?

Answer 36

- Marine conservation zones which are areas in water that are designated for wildlife to recover and repopulate such as areas where fishing and tourism aren't allowed - Wildlife reserves are the same but on land and are actively managed to conserve wildlife

Question 37

What are 3 examples of ex situ methods of maintaining biodiversity?

Answer 37

- Botanical gardens provide a wide range of plant species with the optimal conditions for growth - Seed banks are where seeds of a variety of plant species are stored in water and temperature controlled environments to keep them viable for longer. These are stored as a backup for potential plant species that may go extinct - Captive breeding involves reproducing animals in zoos and aquariums to increase the number of endangered species and these individuals can then be reintroduced into the wild

Question 38

What are 3 examples of international and local conservation agreements?

Answer 38

- Convention on International Trade in Endangered Species (CITES) - The Rio Convention on Biological Diversity (CBD) - The Countryside Stewardship Scheme (CSS)

Question 39

What is CITES?

Answer 39

A treaty that regulates the trade of international animals, plants and their products which requires cooperation and agreement between countries.

Question 40

What is CBD?

Answer 40

172 countries met in Rio and came up with 3 agreements: - Countries must come up with strategies for sustainable development - To stabilise greenhouse gas emissions and concentrations within the atmosphere - To prevent the destruction of fertile land into desert and reduce the effects of drought

Question 41

What is CSS?

Answer 41

Payments were made to farmers and other land managers in order to enhance and conserve English landscapes. Grants were also available for capital works such as hedge laying, planting and dry-stone walls.