4.2 Biodiversity

Question 1

What is biodiversity?

Answer 1

Biodiversity is a measure of the number and variety of species living in an ecosystem.

Question 2

What is habit diversity?

Answer 2

The number of different habitats in an ecosystem.

Question 3

What is species diversity?

Answer 3

Examining the different species living in a Han and measuring the species richness and species evenness. This can be measured using the Simpson’s index of diversity.

Question 4

What is genetic diversity?

Answer 4

Genetic variation between individuals of the same species.

Question 5

What is species richness?

Answer 5

Species evenness refers to the number of individuals of the same species in a given area or ecosystem.

Question 6

What is sampling?

Answer 6

Sampling is selecting a small area or areas in a habitat to study. It is better to sample a habitat because studying every part of it would be to time consuming.

Question 7

What is random sampling?

Answer 7

Random sampling is selecting areas of the habitat to study in a random manner. This eliminates bias. Enough samples have to be taken so that the data is representative of the habitat.

Question 8

What are the advantages of random sampling?

Answer 8

Data is not biased by selective sampling.

Question 9

What are the disadvantages of random sampling?

Answer 9

Rare species may be missed, leading to an underestimate of biodiversity.

Question 10

What are non-random sampling methods?

Answer 10

Opportunistic - deliberate samples chosen during data collection in order to get representative data.
Stratified - choosing two different areas in a habitat to sample.
Systematic - samples taken at fixed intervals across a habitat, e.g. transect.

Question 11

What are the advantages of non-random sampling?

Answer 11

Ensures areas of a habitat are sampled.
Can identify changes in a habitat.

Question 12

What are the disadvantages of non-random sampling?

Answer 12

Data may be biased and some areas may be over-represented.

Question 13

What are the ways to sample plants?

Answer 13

Frame quadrats,
Point quadrats,
Line transect,
Belt transect.

Question 14

What are frame quadrats?

Answer 14

In frame quadrat, the species richness and species evenness are measured. Each square is 4% of the quadrat area. So if it covers 5 squares, it covers 20% of the ground.

Question 15

What are point quadrats?

Answer 15

In a point quadrat, the species touching each pin are counted. Count all the plants touched by the pin. Two or more species may cover the same ground where plants overlap.

Question 16

What are transects?

Answer 16

Transects are used to measure the change in species across an area, for example a sand dune.

Question 17

What are the 2 different types of transects?

Answer 17

Line transects,
Belt transects.

Question 18

What is a line transect?

Answer 18

With a line transect, quadrats are placed at regular intervals along the line.

Question 19

What is a belt transect?

Answer 19

With belt transect, the species richness and species evenness are measured between two lines.

Question 20

What are the ways to sample plants?

Answer 20

Pitfall traps,
Kick sampling,
Sweep net,
Pooters.

Question 21

What are pitfall traps?

Answer 21

Pitfall traps are set below the ground so that small invertebrates will fall in.

Question 22

What is kick sampling?

Answer 22

Kick sampling collects animals that live at the bottom of a stream or pond. A net is held under the water while the streambed is agitated by kicking for serval minutes.

Question 23

What is net sweeping?

Answer 23

A sweep net collects animals that live in a field or long grass. the net is swept through the field to collect insects.

Question 24

What are pooters?

Answer 24

Small invertebrates are pulled into pooters on a straw

Question 25

What happens after counting animals?

Answer 25

the animals are released unharmed after counting.

Question 26

How do you measure biodiversity?

Answer 26

The Simpson’s index of diversity is a measure of the level of biodiversity of the habitat.

Question 27

What do you need to calculate Simpson’s index of diversity?

Answer 27

You need to measure the species richness and species evenness within a habitat. This can be done by quadrats or a transect, and counting the numbers of individuals of each species within each quadrat.

Question 28

How do you calculate genetic diversity?

Answer 28

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

Question 29

What causes genetic diversity?

Answer 29

Genetic diversity is caused by the number of alleles of each gene. If a gene has two or more alleles it is called polymorphic.

Question 30

What is genetic diversity?

Answer 30

Genetic diversity is the amount of genetic variation within a population. Usually a population with a large number of individuals has a high diversity. A population with a small number of individuals, such as in a rare species, will have low genetic diversity.

Question 31

How can we observe genetic diversity?

Answer 31

We can observe genetic diversity by looking at the phenotypes (observable traits) of the population. Many differences in phenotype, e.g. fur colours, will indicate high genetic diversity.

Question 32

What human factors affect biodiversity?

Answer 32

Human population growth,
Monoculture,
Climate change,
Extinction

Question 33

How does human population growth affect biodiversity?

Answer 33

The increase human need for land, food and resources reduces the habitats and food sources for other species. e.g. cutting down forest to use land for housing.

Question 34

How does monoculture affect biodiversity?

Answer 34

When only one species of a plant is planted in an area at a time, there is less space for other species. e.g planting a forest of palm tress for palm oil.

Question 35

How does climate change affect biodiversity?

Answer 35

Increased human activity increases climate change which affects the habitats of other species . e.g. increased flooding of low lying areas.

Question 36

How does extinction affect biodiversity?

Answer 36

Increased human activity increases the extinction rate of many species .e.g. the Japanese river otter became extinct in 2012 due to hunting and human pollution of its habitat.

Question 37

What are the main reasons to maintain biodiversity?

Answer 37

Ecological - protecting keystone species and maintaining genetic variation.
Economic - services and products that plants and animals provide for us, such as maintaining the nutrients in the soil, timber, fruit and honey.
Aesthetic - protecting landscapes: enjoying the natural beauty of the planet, e.g. going on holiday or sitting in a garden.

Question 38

What does in situ mean?

Answer 38

In situ means that the plants or animals are being kept in their natural environment.

Question 39

What are examples of in situ conservation?

Answer 39

Conservation zones can be created for marine wildlife. In these areas, no fishing or hunting is allowed. Terrestrial animals can live inside wildlife reserves. In these areas, no hunting is allowed and rangers protect the animals.

Question 40

What are the advantages of in situ conservation?

Answer 40

Biodiversity in that ecosystem is protected.

Question 41

What are the disadvantages of in situ conservation?

Answer 41

Difficult to carry out breeding programmes.
Animals may not have access to medical care.

Question 42

What does ex situ mean?

Answer 42

Ex situ means that the plants or animas are being kept outside of their natural environment.

Question 43

What are some examples of ex situ conservation?

Answer 43

Seeds can be kept in seed banks to protect them for future generations. Plants may be grown in botanical gardens, such as Kew gardens so they can be conserved and studied. Animals may be kept in a zoo or aquarium.

Question 44

What are the advantages of ex situ conservation?

Answer 44

can carry out breeding programmes,
prevent extinction of species,
Protection from hunting,
Animals will have access to medical care.

Question 45

What are the disadvantages of ex situ conservation?

Answer 45

Does not protect the biodiversity of the original habitat,
Will lose some genetic diversity,
Difficult to reintroduce species back into the wild.