Biodiversity And Sampling

Question 1

What is biodiversity

Answer 1

The variety of living organisms that are found in a region

Question 2

Why is it important that humans don’t affect biodiversity

Answer 2

All the living organisms in a habitat depend on each other, so it’s important that human activity doesn’t have a negative effect on biodiversity.

Question 3

What are the 3 levels that biodiversity can be assessed at

Answer 3

Habitat/ecosystem biodiversity, species biodiversity and genetic biodiversity

Question 4

What does habitat biodiversity refer to

Answer 4

All the different habitats that are found in an area

Question 5

What will each habitat do

Answer 5

it will support a range of different species of animals, fungi and microorganisms

Question 6

What will an area with a rich habitat biodiversity have

Answer 6

A wide range of species

Question 7

What is species biodiversity

Answer 7

It tells us the species living in a certain area and it consists of 2 parts:

Question 8

What do scientists do to work out species biodiversity

Answer 8

By carrying out sampling

Question 9

What are the two different types of sampling

Answer 9

Random or non-random sampling

Question 10

What are the areas in random sampling selected by

Answer 10

Using random numbers which determine the coordinates on a map

Question 11

What does random sampling do

Answer 11

Because the area isn’t chosen by humans it reduces the chance of sampling bias.

Question 12

What might humans do if they choose the sampling site

Answer 12

They might choose the area that is easiest to reach or with a large number of organisms. However, these areas may not represent the whole area reducing reliability.

Question 13

What is opportunistic sampling an example of and what is it and what is a negative of it

Answer 13

It is an example of non-random sampling
Where the scientists select the organisms that are readily available. However these organisms may not be representative of all the organisms making it unreliable.

Question 14

What is done during stratified sampling

Answer 14

The population is divided into subgroups or strata.

However the number of each group sampled has to be representative of the whole population.

Question 15

What is systematic sampling

Answer 15

Is used when there is a gradual change in the habitat from one place to another.

And is used to determine how the abundance of organisms changes as the habitat changes. Or how the features of the organisms change.

Question 16

What are the two ways to do systematic sampling

Answer 16

By using a belt transect or line transect

Question 17

How can a line transect be used for systematic sampling and what is a negative

Answer 17

A measuring tape is placed across the habitat and any organism touching the tape is sampled.

However these organisms may number of organisms touching the tape may be very small

Question 18

What is a belt transect and how is it used for systematic sampling

Answer 18

We place two parallel tapes across the habitat.
Any organisms found between the two tapes are sampled (e.g by using a quadrant)

Question 19

When we sample organisms at regular intervals along the transect what is it called

Answer 19

An interrupted belt transect.

Question 20

What can we do by sampling

Answer 20

We can estimate the abundance of an organism in a given area
We can also estimate features of an organism for example the mass.

Question 21

What is a problem with sampling

Answer 21

Is the issue of chance
Where if we select an organism there is a chance that, the organism may not be typical of the whole group.

Question 22

How is the problem with sampling reduced

Answer 22

By sampling a very large number of organisms

Meaning the measurements we take are more representative of the entire population —> increasing reliability

Question 23

What do we determine when sampling

Answer 23

Species evenness and richness

Question 24

How can insects be sampled with a sweeping net

Answer 24

The net is swept over plants several times which traps any insects present.

Question 25

How can we use a poster to catch small insects

Answer 25

A poster consists of two tubes The trapping tube which is placed near the insect we want to catch and we place the mouthpiece tube in our mouth and gently inhale The insect is now sucked into the trapping tube and into the container The mouthpiece tube has a piece of cloth to prevent the insect being sucked into the mouth.

Question 26

What are pitfall traps and what do they do

Answer 26

It is a container sunk into the ground and over the trap we place a cover which prevents rainwater from entering. Ground level animals fall into the trap which is deep enough to prevent them crawling out.

Question 27

What can we use to sample tiny organisms in soil

Answer 27

A Tullgren funnel

Question 28

What does a Tullgren funnel look like

Answer 28

DRAW IT

Question 29

What happen in a Tullgren funnel

Answer 29

A light bulb heats the surface of the soil causing the animals in the soil to move downwards away from the heat. Once they reach the bottom of the funnel they then fall into the container.

Question 30

What is kick sampling used for

Answer 30

It is used to sample for bottom-dwelling animals in the river bed

Question 31

How is kick sampling done

Answer 31

A net is placed downstream and the scientist gently kicks the river bed to dislodge any rocks or pebbles Any organisms which are disturbed move downstream and are caught in the net

Question 32

What is a frame quadrant used to sample

Answer 32

Slow moving or static animals

Question 33

How is a frame quadrant used to sample slow moving static animals

Answer 33

It is placed on the ground and any animals within the quadrant are sampled

Question 34

What can quadrat sampling also be used to sample and how is it interpreted

Answer 34

Be used to sample the plants in a habitat Where the value of the number of the species as a mean/ m2 is the density per m2

Question 35

How can we also use quadrants when plants have a very large amount in an area or are difficult to count

Answer 35

We look at how many squares in the quadrat contain the plant and this is reported as a percentage frequency

Question 36

What happens if a plant occupies a large amount of the quadrat

Answer 36

We can use percentage cover which is when we estimate by eye the percentage of the total area that is occupied by the plant

Question 37

What is a negative of percentage cover

Answer 37

It is not very accurate however it is very quick

Question 38

How can we increase the reliability of sampling by quadrants

Answer 38

By placing the quadrat at multiple positions and then calculating a mean

Question 39

What can be used instead of a bar quadrat

Answer 39

A point quadrat which is a wooden bar with holes in it, we position the bar over the ground and place metal pins into each hole. We count any plant that is touched by the pin.

Question 40

What is genetic biodiversity also referred to as

Answer 40

The gene pool

Question 41

What do all of the individuals of a species have

Answer 41

The same genes

Question 42

What are monomorphic genes

Answer 42

Genes that only have one version

Question 43

What are polymorphic genes

Answer 43

Genes that have different versions called alleles

Question 44

What happens when breeding takes place in a small population

Answer 44

There is a low genetic biodiversity, and the number of different alleles within this population is very small. This can cause inbreeding within the population - which can lead to genetically-linked health problems.

Question 45

What happens when breeding takes place in a large population

Answer 45

There are a large number of alleles and a high level of genetic biodiversity

Question 46

What can be used to measure genetic biodiversity quantitatively

Answer 46

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

Question 47

What is a gene loci

Answer 47

The position of the genes on a chromosome

Question 48

What are the two ways that genetic biodiversity can increase

Answer 48

1. Random mutations can take place creating new alleles 2. Migration between population can transfer alleles

Question 49

What is gene flow

Answer 49

Migration between population can transfer alleles

Question 50

What are factors that can cause genetic biodiversity to decrease (1)

Answer 50

As a result of natural selection individuals with advantageous alleles are more likely to survive and reproduce than individuals with less advantageous alleles. And overtime the less advantageous alleles will become less common in the population.

Question 51

What are factors that can cause genetic biodiversity to decrease (2)

Answer 51

In selective breeding or artificial selection, humans select individuals in a population for breeding. As these individuals have desirable alleles, individuals without the desired alleles are not allowed to breed, so over time these alleles disappear from the population.

Question 52

What are factors that can cause genetic biodiversity to decrease (3)

Answer 52

Sometimes selective breeding will lead to breeds that fall out of favour and become rare.

Question 53

What are factors that can cause genetic biodiversity to decrease (4)

Answer 53

sometimes individuals of a wild species will decrease e.g due to hunting, so the size of the gene pool is very small.

Question 54

What are factors that can cause genetic biodiversity to decrease (5)

Answer 54

it can also be reduced by cloning plants, decreasing the genetic biodiversity within the species.

Question 55

What are factors that can cause genetic biodiversity to decrease (6) (bottleneck)

Answer 55

If gene pools are severely reduced scientists call this a genetic bottleneck and this severely reduces genetic biodiversity within

Question 56

What are factors that can cause genetic biodiversity to decrease (7) (founder effect)

Answer 56

Sometimes a small number of individuals move forming an isolated population with a limited biodiversity this is called the Founder effect.

Question 57

What are factors that can cause genetic biodiversity to decrease (8) (genetic drift)

Answer 57

Sometimes genetic biodiversity can change due to random chance and this is called genetic drift. For example some individuals in a species may not reproduce and if these individuals are the only ones with a certain allele then that allele will be lost. This is most likely to happen when a population is small and has a low genetic biodiversity e.g after a genetic bottleneck takes place.