B6.1

Question 1

What is the abundance of an organism?

Answer 1

How many individuals are found in an area. (Population size)

Question 2

What is the distribution of an organism?

Answer 2

Location of an organism in a habitat. (Part of a field)

Question 3

Why are samples taken instead of investigating a whole ecosystem or area?

Answer 3

It is too time consuming. A sample allows you to gain an estimate to size up to the total area.

Question 4

How is abundance estimated?

Answer 4

Count the number of individuals in a sample area and work out the percentage cover.

Question 5

Describe the two ways you can study the distribution of an organism.

Answer 5

• Measure how common an organism is in 2 sample areas and compare.
• Study distribution changes across a transect line.

Question 6

Describe the sampling technique used to collect ground insects.

Answer 6

• Use a pooter
• Suck into the mouthpiece connected to a tube, and have the longer tube over an insect, this will suck the insects into the jar.

Question 7

Describe the sampling technique used to collect flying insects.

Answer 7

• Use a sweep net

- Sweep a large net to catch flying insects or those in long grass.

Question 8

Describe the sampling technique used to collect insects further under the ground.

Answer 8

• Pitfall traps
• Dig a hole to place a jar with possibly some food to attract the crawling invertebrates such as beetles and spiders
• Cover it with leaves or a roof so rainwater doesn’t enter and the insects can’t escape.

Question 9

Describe the sampling technique used to collect water organisms.

Answer 9

• Kick sampling/pond nets
• Wade through the first sample area and kick the river bank to disturb the mud,
• Hold the pond net in front of you downstream to capture any organisms released into the flowing water.

Question 10

Describe the sampling technique used to collect insects in trees or bushes.

Answer 10

• Tree beating
• Place a large white cloth or paper under a tree or bush
• Shake or beat the tree to dislodge invertebrates which will fall onto the cloth.

Question 11

How are unknown organisms identified?

Answer 11

Using keys

• Dichotomous - correct answer to a question tells you which question to go to or the organism eventually.
• Spider - yes no questions

Question 12

Describe the process of capture-recapture and how it is used to estimate animal population.

Answer 12

• Capture a sample of the population, mark them and release back into environment
• Recapture at a later date. Count the number of organisms and the number marked.
  Use formula to estimate.
  population size = (no. in 1st sample x no. in 2nd sample)/(no. in 2nd sample marked)

Question 13

What assumptions have been made when conducting capture-recapture?

Answer 13

• No population change (births or deaths)

- When marking animals the chance of survival hasn’t been affected (e.g. more visible to predator).

Question 14

Describe the method used to sample plants.

Answer 14

• Place a quadrat on the ground and record and count the no. of organisms within each section.
• Take a number of samples and take a mean, the more samples the more reliable your results are.
• Work out the whole population of an organism by multiplying the mean per area by total area.

Question 15

What biotic factors affect distribution of an organism?

Answer 15

• Competition between species, there may be a different distribution if competition did/didn’t exist.

Question 16

What abiotic factors affect distribution of an organism?

Answer 16

• Temperature, moisture, light intensity and soil pH.
• E.g. light intensity is higher where there are less trees covering the grass, so daisies are more common in the open due to more light intensity.

Question 17

How do you measure abiotic factors?

Answer 17

• Temperature - thermometer
• Soil pH - take a sample of soil, wet it and use indicator or a pH probe.
• Light intensity - data logger

Question 18

For species, what are the consequences when biodiversity is lost?

Answer 18

The removal of one species affects another, for example the species that is removed maybe prey for a predator which could endanger that species.

Question 19

State 4 examples of how biodiversity is lost.

Answer 19

Deforestation
Agriculture
Hunting and fishing
Pollution

Question 20

What is random sampling?

Answer 20

Random sampling is where the area to be sampled is selected by chance.

Question 21

What are the advantages of random sampling and how can it be carried out when sampling plants?

Answer 21

The investigation will not be bias.

Mark out a grid, generate coordinates and use a random number generator to pick the coordinates.

Question 22

What is non-random sampling?

Answer 22

E.g a transect, the sampling is conducted over a selected area if that is where you want to investigate.

Question 23

For species, what are the consequences when biodiversity is lost?

Answer 23

The removal of one species affects another, for example the species that is removed maybe prey for a predator which could endanger that species.

Question 24

What are the consequences of deforestation?

Answer 24

• Reduces the number of trees
• Removes habitats for some species
• Some species food source has been lost
• Affects the food chain as there is no producer, then no consumers or predators.

Question 25

What is agriculture?

Answer 25

Farming for crop and yield to be sold for food consumption.

Question 26

What are the advantages of random sampling and how can it be carried out when sampling plants?

Answer 26

The investigation will not be bias.

Mark out a grid, generate coordinates and use a random number generator to pick the coordinates.

Question 27

What is deforestation and why does it occur?

Answer 27

Permanent removal of large areas of forest. Provides wood for burning and fuel, giving space for agriculture, roads and buildings.

Question 28

What is eutrophication?

Answer 28

When fertilisers run into lakes causing algae to bloom, this prevents light from reaching the bottom of the lake, the plants die as they can’t photosynthesise. The dead plants and algae decompose reducing oxygen levels killing the fish.

Question 29

What are some methods used to prevent biodiversity loss?

Answer 29

Conservation
Captive breeding
Seed banks

Question 30

How can overfishing reduce biodiversity?

Answer 30

• Kills or significantly reduces the population of the species of fish, reducing food for other animals and other marine species may be caught and killed

Question 31

What is conservation?

Answer 31

Conservation is action taken to prevent natural habitats which increases an organisms chance of survival, allowing them to reproduce. Also protects interlinked species.

Question 32

What is captive breeding?

Answer 32

Breeding animals in human controlled environments such as zoos or aquariums. Giving the animlas shelter, food, vet treatment, predator free environment.

Question 33

For nature reserves, what kind of active management is required?

Answer 33

• Controlled grazing to allow the plants to grow back.
• Restricting human access, prevent plants from being trampled.
• Feed animals
• Reintroduce species.

Question 34

What are the aims of captive breeding?

Answer 34

• Healthy stable population of species

- Gradually reintroduce species back into their natural habitat.

Question 35

Drawbacks of captive breeding.

Answer 35

• Genetic diversity will be low as few breeding partners are available.
• Organisms may not be suitable to release into the wild as the predators may not know how to hunt for food.

Question 36

What are seed banks and their purpose?

Answer 36

• Help conserve plants

- Seeds carefully stored so that new plants can be grown in the future. It is an example of a gene bank.

Question 37

What are conservation agreements?

Answer 37

In order to conserve biodiversity, local and international agreements are kept to preserve the habitats of individual species and animals migrate between countries and global action is required.

Question 38

What are examples of international agreements?

Answer 38

IUCN (international union for conservation of nature).
- Produces a red list of endangered species and countries work together to conserve species.
CITES (convention on international trade of endangered species of wild fauna and flora)
- Regulates trade of wild animals and plants, protects 35000 species.

Question 39

What are the aims of ecotourism?

Answer 39

• Allow tourism whilst not damaging the natural habitat or local community.

Question 40

How is tourism kept eco-friendly?

Answer 40

• Tourists are restricted to certain areas.
• Footpaths for tourists
• Ensures breeding grounds are not destroyed.

Question 41

What are the negatives of eco tourism?

Answer 41

• Tourists movement such as repeated use of hike trails or vehicles carrying tourists contribute to soil erosion and other changes.

Question 42

How do scientists monitor pollution?

Answer 42

• Regular samples of plants and animals are taken to see the number of species left, a decrease suggests a change in the environment (worse pollution).

Question 43

What are indicator species?

Answer 43

Organisms used to measure environmental qualities, their presence or absence tells scientists that an area is polluted.

Question 44

Give an example of an indicator species and what its role is.

Answer 44

Lichen, used to measure air pollution (specifically sulfur dioxide)
- They get their food from rainwater and the air which has dissolved pollutants, less lichen - higher pollution.

Question 45

How are organisms used to monitor water pollution?

Answer 45

Water pollution is caused by the discharge of harmful substances into water.
Higher pollution = lower oxygen levels.
Indicator species tell you the amount of oxygen present in the waters.