B6.1

Question 1

Sampling

Answer 1

Taking observations or measurements from a small area

Question 2

Methods of sampling animals

Answer 2

Pooter - suck on a mouthpiece to draw insects into the holding chamber (a filter stops organisms from entering your mouth)

Sweep nets - sweep a large net through the air to catch flying insects or those in long grass

Kick sampling - ‘kick’ a river bank or bed to disturb mud and vegetation. Then hold or a net downstream to collect any organisms released into the flowing water

Tree beating - beat or shake the tree to dislodge any invertebrates, and catch them with a large white cloth

Pitfall traps - dig a hole into the ground, which crawling invertebrates such as beetles can fall into. Cover the hole with a roof do it doesn’t fill with rain water

Question 3

Identification keys

Answer 3

A way to identify living organisms through keys, which ask a series of questions about an organism’s characteristics

Question 4

Branched key / spider key

Answer 4

Answered with yes or no

Question 5

Numbered key / dichotomous key

Answer 5

The correct answer to a question tells you which question you should answer next

Question 6

Estimated population size

Answer 6

Estimated population size = (first sample size x second sample size) / number of recaptured marked individuals

Question 7

Method of sampling plants

Answer 7

Using a Quadrat, record the type and number of organisms within each section

Multiply the mean population by the total area to find the total population

Question 8

Random sampling

Answer 8

Mark out a grid, then use a random number generator to determine the coordinates

Prevents bias to more interesting areas

Question 9

Non-random sampling

Answer 9

Use a transect (samples taken across a line) to see how the distribution of organisms varies over a distance

Question 10

Biodiversity

Answer 10

The variety of living organisms in an area

Question 11

Why is biodiversity important

Answer 11

Because many species are interconnected, so the removal of one species will affect other species

Biodiversity is essential for maintaining a balanced ecosystem

Question 12

Biodiversity is lost through: deforestation

Answer 12

The permanent removal of large areas of forest

Reduces the number of trees and number of supported and animal species

Food source/home is lost, animals may die

Question 13

Biodiversity is lost through: agriculture

Answer 13

Removing hedgerows: reduces the number of plant species and destroys the habitat of animals such as mice

Using pesticides: removes the food source of other organisms, and can accumulate in the food chain and kill animals that weren’t targeted

Question 14

Biodiversity is lost through: hunting and fishing

Answer 14

Hunting/fishing decreases the target species’ population, which removes food for other species

This may allow the unchecked growth of other animal/plant species

Question 15

Biodiversity is lost through: pollution

Answer 15

Generally, the more populated the area, the fewer number of species that can survive

Question 16

Biodiversity is preserved through: conservation

Answer 16

Means protecting a natural environment to ensure habitats aren’t lost. Interlinked species are also supported. This involves:

Controlled grazing (gives plant species time to recover)

Restricting human access (providing paths so plants aren’t trampled)

Feeding animals (to ensure as many organisms survive long enough to reproduce)

Question 17

Biodiversity is preserved through: Captive breeding

Answer 17

Means breeding animals in human controlled environments such as a zoo. This involves:

Creating a stable, healthy population

Gradually reintroducing the species back into its natural habitat

Maintaining genetic diversity can be difficult since few breeding partners are available

Organisms born into captivity may not be suitable for release (predators may not know how to hunt for food)

Question 18

Biodiversity is preserved through: preventing extinction

Answer 18

Seed banks are being used to ensure that new plants may be grown in the future

Question 19

Conservation agreements

Answer 19

Agreements to conserve biodiversity

Internationally- allow animals to naturally move between countries

Locally - being paid by the government to maintain the landscape

Question 20

Ecotourism

Answer 20

A type of tourism that aims to ensure that tourism doesn’t have a negative impact on the natural environment or local communities

Benefits: Tourists are restricted to certain areas, such as footpaths, to make sure that animal breeding grounds are not disturbed, or endangered plants trampled

Tourists see an undisturbed view of nature

Costs: There is evidence that tourist movements repeatedly over the same trail may contribute to soil erosion and other habitat changes

Tourism is a very unstable source of income

Question 21

Indicator species

Answer 21

Organisms used to measure environmental quality

Question 22

Lichens

Answer 22

Used to monitor air pollution in the form of sulfur dioxide

They have no root system, so they rely on the air for their nutrition

Rainwater contains just enough nutrients to keep them alive, so air pollutants can easily damage them and prevent their growth

Lack of lichens = sign of high pollution

Question 23

Pollution in water

Answer 23

Unpolluted - mayfly larva

Low pollution - freshwater shrimp

High pollution - water louse

Very high pollution - sludgeworm