Biodiversity

Question 1

conservation

Answer 1

preservation of ecosystems and the organisms that live within them

Question 2

Reasons for maintaining biodiversity

Answer 2

• moral reasons: humans should respect other living organisms
• aesthetic reasons: people enjoy seeing the variety of living organisms in different habitats
• ecosystem structure: some organisms have an important role in ecosystems (e.g. decomposers), and if they are lost food chains become more unstable
• usefulness: some species are useful to humans, and produce life-saving drugs or are a source of food

Question 3

reforestation

Answer 3

replanting forests where they have been destroyed, e.g. to create farmland

Question 4

Why has deforestation happened a lot over the past 100 years?

Answer 4

paper and wood products are in higher demand as the population increases, so more trees need to be cut down

Question 5

effects of deforestation on living things

Answer 5

• less oxygen is produced
• less CO2 is absorbed, leading to an increase in levels
• species die off as they lose habitats
• less water is absorbed so rivers are more likely to flood

Question 6

advantages of reforestation

Answer 6

• restores habitats for species that are endangered (e.g. rainforest reforestation helps to conserve many species)
• reduces the concentration of CO2 in the air as the trees photosynthesise
• tree roots bind together the soil and reduce soil erosion
• affects local climate, e.g. reducing the range of temperature variation

Question 7

endangered

Answer 7

a species that has declining numbers or low numbers and is at risk of going extinct

Question 8

Why are animals bred in captivity?

Answer 8

• their natural habitats are being destroyed for resources, crops or living space
• they are hunted/poached

Question 9

meaning of bred in captivity

Answer 9

they are born in zoos instead of the wild

Question 10

Why is it easier to conserve species in captivity rather than the wild?

Answer 10

• less predators
• more access to food

-less likely to be hurt/die

• numbers can be tracked easier
• can be moved to other places with the same species to reproduce

Question 11

Why is it difficult to release captive animals back into the wild?

Answer 11

• they have been fed by humans so don’t know how to hunt in the wild
• used to a safe environment so are more vulnerable to threats encountered in the wild

Question 12

Suggest why scientists monitor the populations of top predators very closely when assessing biodiversity [2]

Answer 12

if there are plenty of top predators then there is plenty of energy being transferred through the food web in the ecosystem

this suggests high biodiversity

Question 13

Farmers in the UK are encouraged to keep hedges around their fields.

Explain how keeping hedges around fields can help maintain biodiversity. [2]

Answer 13

-provides food/shelter/nesting places

so

• more species of animals supported
• more food chains possible
• different species can reproduce