B17- Biodiversity and ecosystems ♻️

Question 1

What is biodiversity ?

Hint: variety

Answer 1

• biodiversity, is the variety of all the different species of organisms on Earth.

Question 2

What is one way that species help to maintain the environment ?

Answer 2

• decomposers, break down the remains of dead organisms.

Question 3

What does a high level of biodiversity mean ?

Answer 3

• a high level of biodiversity, means there’s lots of different species.

Question 4

How are humans having a negative effect on biodiversity ?

Answer 4

• an example of how humans having a negative effect on biodiversity, is deforestation.
• tropical forests contain a very rich biodiversity; large areas of these forests are now being destroyed to provide land.
• this is because the land is often used for rice fields or for grazing cattle.
• and in many cases, the land is used to grow crops which is then used to make biofuels.

Question 5

Humans are having a negative effect on biodiversity. What are some of the causes for this ?

Answer 5

• deforestation: large areas of these forests are now being destroyed to provide land.
• because the land is often used for rice fields or for grazing cattle.
• and in many cases, the land is used to grow crops which is then used to make biofuels.

Question 6

Why are humans using more of the Earth’s resources than ever before ?

Answer 6

• the population of humans has increased massively over the last hundred years
• the average standard of living has also increased.

Question 7

What are the three types of pollution ?

Answer 7

• the three types of pollution are: water, land and air pollution

Question 8

What are the three types of waste, that can lead to water pollution ?

Answer 8

• the three types of waste, that can lead to water pollution are:
• sewage
• fertilisers
• and, toxic chemicals.

Question 9

How can sewage lead to water pollution occurring ?

Answer 9

• sewage- humans produce a large amount of sewage.
• ; sewage contains urine and faeces which is simply released into nearby waterways, in some countries.
• This can cause water pollution because large [and excess] amounts nutrients, are introduced into the water. [e.g- nitrogen and phosphorous.]- causing eutrophication

Question 10

What is eutrophication ?

Hint: enriched

Answer 10

• eutrophication, is the process by which a body of water becomes enriched with nutrients, [therefore] leading to excessive growth of algae and other aquatic plants

Question 11

How can fertilisers lead to water pollution occurring ? 🐟

Hint: dissolved oxygen

Answer 11

• rivers and streams can be polluted, with fertilisers from farms.
• this means fertilisers can cause dissolved oxygen levels to fall, which can kill aquatic organisms [such as fish-] and reduce biodiversity

Question 12

How can toxic chemicals lead to water pollution occurring ?

Hint: nervous system

Answer 12

• toxic chemicals- sometimes toxic chemicals are released into rivers, from factories.
• This can kill animals in the river because, it can cause damage to their nervous systems- which reduces biodiversity

Question 13

What are the two types of waste, that can lead to air pollution ?

Answer 13

• the twoe types of waste, that can lead to air pollution are: acidic gases and smoke.

Question 14

How can acidic gases lead to air pollution occurring ?

Answer 14

• burning coal in power stations can release acidic gases, which can cause acid rain- acid rain is a result of air pollution.
• and acid rain can dissolve nutrients, [e.g-magnesium and calcium] that trees need to be healthy.

Question 15

How can smoke lead to air pollution occurring ?

Hint: released

Answer 15

• burning [coal] can also release smoke, which can kill plants and animals- therefore reducing biodiversity
• ; if released into the atmosphere, it can pollute the air and then contribute to climate change.

Question 16

What are the two types of waste, that can lead to land pollution ?

Answer 16

• the three types of waste, that can lead to water pollution are: landfill and toxic chemicals

Question 17

How can landfill, lead to land pollution occurring ?

Hint: waste

Answer 17

• waste can pollute the land. For example, millions of waste is dumped in landfills.
• and these landfills can then destroy habitats, for plants and animals.

Question 18

How can toxic chemicals, lead to land pollution occurring ?

Hint: leach

Answer 18

• toxic chemicals can leach out of landfills and pollute the soil- which can then lead to land pollution occurring

Question 19

List some resources that humans are using up

Answer 19

• fossil fuels for energy and raw materials
• minerals from rocks (e.g. gold is VERY expensive as we’ve mined most of it.
• open spaces to provide soil to grow food.
• as most of the water is in the sea, we are running out of fresh water to: grow food, for cleaning, drinking and waste removal.

Question 21

Why is a good level of biodiversity important, to the future of the human species ?

Answer 21

• a good level of biodiversity is important, to the future of the human species
• This is because without a wide range of animals, plants and microorganisms, we can’t have the [healthy] ecosystems we rely on to provide us with the air we breathe and the food we eat

Question 21

Describe some effects of human population growth.

Answer 21

• as the population grows, more resources are used so more energy is required.
• this means, there is an increase in the use of fossil fuels and an increase in the waste produced.
• this will then leads to an increase in pollution.
• This increase in pollution, can then affect the environment.
• ; there’s also an effect on land and resources

Question 22

How can the human population growth, effect the land we use ?

Answer 22

• More land is needed for homes, shops, industrial sites, roads destroying [existing] habitats.
• More land is needed for farming- destroying natural plant and animal communities.
• vast areas of land to obtain rocks & metal ores are dug up– meaning natural ecosystems are lost= a loss of both plant and animal species.

Question 23

Explain why human population change differs from population change of other animals.

Answer 23

• in nature, population chamge is normally controlled by: predators, a lack of food, build up of waste and disease controls a population.

Question 24

Explain how human population change differs from population change of other animals.

Answer 24

• ; with humans this isnt the case, as we grow our own food using fertilisers and pesticides – meaning plenty of food available
• we cure diseases using medicine – meaning there is a limited number of deaths
• humans have no natural predators – also meaning there is a limited number of deaths
• and we also remove and dump waste elsewhere – meaning better sanitation, and therefore once again, limiting the number of deaths.

Question 25

Suggest and evaluate solutions to the problems, caused by human population growth. 🚹🚺

Answer 25

• China attempted the controversial, ‘One Child Policy’ as they realised that their supply was not meeting their demand.
• This is because, weren’t enough resources for the sheer number of people.
• ; although the the birth rate decreased after 1980, sons were generally preferred over daughters- therefore the overall sex ratio in China became skewed toward males.
• [In 2016 there were 33.59 million more men than women]

Question 25

Suggest and evaluate solutions to the problems, caused by human population growth. 🥑🥙🍖🍔

Answer 25

• a solution could be to reduce your personal consumption. To do this, a person could go vegan.
• ; although the consumption of meat would be reduced, more people would be at risk of being deficient in certain nutrients.
• This is because they wouldn’t be eating certain nutrients [e.g- calcium and vitamin B12] typically found in dairy and meat

Question 26

How does a high biodiversity, make an ecosystem stable ?

Answer 26

• this makes an ecosystem more stable because, lots of different species mean that the ecosystem is less dependent on one species.
• and therefore if the population of a species falls, it’s less likely to affect the whole ecosystem.

Question 27

• Fill in the gaps: In the UK, sewage is treated before being released
• though in some cases, untreated sewage can accidentally be released into rivers or streams.

Answer 27

• in the UK, sewage is treated before being released
• though in some cases, untreated sewage can accidentally be released into rivers or streams.

Question 28

How can toxic chemicals kill organisms ?

Answer 28

• ; in some cases, toxic chemicals are simply dumped directly onto the land
• and those chemicals can kill living organisms.
• This is because, when the toxic compound comes in contact with or is absorbed by body tissues, these compounds can then interact with parts of the body.