B18. Biodiversity and Ecosystems

Question 1

What is meant by the term ‘biodiversity’

Answer 1

Biodiversity is a measure of the variety of all of the different species of organisms on Earth, or within a particular ecosytem.

Question 2

Why is a high biodiversity an advantage

Answer 2

It ensure a more stable ecosystem where more organisms can survive.

Question 3

What are the main threats to biodiversity?

Answer 3

The main threats to biodiversity include habitat destruction, pollution, climate change, overexploitation of natural resources, and invasive species.

Question 4

Explain the importance of biodiversity.

Answer 4

Biodiversity is important for maintaining the health and stability of ecosystems. It provides ecosystem services such as pollination, nutrient cycling, and regulation of climate and water cycles. Biodiversity also has economic, cultural, and aesthetic value.

Question 5

How can biodiversity be conserved?

Answer 5

Biodiversity can be conserved through measures such as habitat preservation, sustainable resource management, captive breeding programs, legislation and policy, and public education and awareness campaigns.

Question 6

Define air pollution.

Answer 6

Air pollution refers to the presence of harmful substances in the Earth’s atmosphere, often resulting from human activities such as burning fossil fuels, industrial processes, and vehicle emissions.

Question 7

What are some common air pollutants?

Answer 7

Common air pollutants include carbon monoxide (CO), sulfur dioxide (SO2), nitrogen oxides (NOx), particulate matter (PM), volatile organic compounds (VOCs), and ozone (O3).

Question 8

How does air pollution impact human health?

Answer 8

Air pollution can cause respiratory problems, such as asthma and bronchitis, cardiovascular diseases, and even lung cancer. Prolonged exposure to certain air pollutants can also impair lung function and lead to premature death.

Question 9

What are the main sources of water pollution?

Answer 9

The main sources of water pollution include industrial discharges, agricultural runoff containing pesticides and fertilizers, sewage and wastewater discharge, and improper disposal of household chemicals and waste.

Question 10

What are the effects of water pollution on aquatic ecosystems?

Answer 10

Water pollution can lead to the decline of aquatic biodiversity, as it can harm fish, amphibians, and other aquatic organisms. It can also disrupt ecosystems by causing algal blooms, oxygen depletion, and habitat destruction.

Question 11

Define land pollution.

Answer 11

Land pollution refers to the contamination or degradation of land resources, often caused by improper disposal of waste, industrial activities, urbanization, and agricultural practices.

Question 12

How does land pollution affect soil quality?

Answer 12

Land pollution can degrade soil quality by introducing harmful chemicals, heavy metals, and other contaminants into the soil. This can disrupt soil fertility, decrease crop yields, and harm soil organisms essential for nutrient cycling.

Question 13

What are the consequences of land pollution?

Answer 13

Consequences of land pollution include loss of biodiversity, contamination of groundwater and surface water, soil erosion, habitat destruction, and adverse effects on human health through the consumption of contaminated food and water sources.

Question 14

Define deforestation.

Answer 14

Deforestation is the permanent removal of forests or trees to make way for other land uses, such as agriculture, urban development, or logging.

Question 15

What are the main causes of deforestation?

Answer 15

The main causes of deforestation include agricultural expansion, logging for timber and paper products, infrastructure development, and urbanization.

Question 16

What are the environmental impacts of deforestation?

Answer 16

The environmental impacts of deforestation include loss of biodiversity, habitat destruction, soil erosion, disruption of water cycles, increased greenhouse gas emissions, and climate change.

Question 17

How does deforestation affect climate change?

Answer 17

Deforestation contributes to climate change by releasing stored carbon dioxide (CO2) into the atmosphere and reducing the Earth’s capacity to absorb CO2 through photosynthesis.

Question 18

Define peat bog destruction.

Answer 18

Peat bog destruction refers to the draining, degradation, or conversion of peatlands for agricultural, forestry, or urban development purposes, leading to the loss of peat and associated ecosystems.

Question 19

What are peat bogs and why are they important?

Answer 19

Peat bogs are wetland ecosystems characterized by the accumulation of partially decomposed organic matter (peat) over thousands of years. They are important for carbon storage, biodiversity, water regulation, and as habitats for specialized plant and animal species.

Question 20

What are the consequences of peat bog destruction?

Answer 20

Consequences of peat bog destruction include the release of stored carbon dioxide (CO2) into the atmosphere, loss of biodiversity and specialized habitats, disruption of water cycles, increased flood risk, and degradation of ecosystem services provided by peatlands.

Question 21

How can deforestation and peat bog destruction be reduced?

Answer 21

Through measures such as sustainable land management practices, reforestation efforts, protection of critical habitats, restoration of degraded ecosystems, and policies aimed at reducing reliance on unsustainable land uses.

Question 22

Define human population explosion.

Answer 22

Human population explosion refers to the rapid and exponential growth of the global human population, particularly observed since the Industrial Revolution.

Question 23

What are some factors contributing to human population explosion?

Answer 23

Factors contributing to human population explosion include advancements in medicine and healthcare, improved sanitation and hygiene, increased food production, and declining death rates.

Question 24

What are the consequences of human population explosion?

Answer 24

Consequences of human population explosion include increased pressure on natural resources, habitat destruction, loss of biodiversity, environmental degradation, competition for limited resources, and social and economic challenges such as poverty, hunger, and inadequate access to healthcare and education.

Question 25

How does human population growth affect biodiversity?

Answer 25

Human population growth can negatively affect biodiversity through habitat destruction, overexploitation of natural resources, pollution, introduction of invasive species, and climate change, leading to loss of species and ecosystems.

Question 26

What is a pyramid of numbers?

Answer 26

It is a graphical representation that shows the number of organisms at each trophic level in a food chain or food web.

Question 27

What are the key characteristics of pyramids of number?

Answer 27

Pyramids of number can be upright, inverted, or even diamond-shaped. They represent the relative number of organisms at each trophic level in a given ecosystem.

Question 28

What is a pyramid of biomass?

Answer 28

A pyramid of biomass is a graphical representation that shows the total biomass (the mass of living material) at each trophic level in a food chain or food web.

Question 29

How do pyramids of number and biomass differ?

Answer 29

Pyramids of number represent the number of organisms at each trophic level, while pyramids of biomass represent the total biomass at each trophic level.

Question 30

How is biomass calculated in a pyramid of biomass?

Answer 30

Biomass is measured in grams per square meter (g/m²) or kilograms per hectare (kg/ha), and it is obtained by drying the organisms (removing all water) and measuring their mass.

Question 31

Why is a pyramid of numbers not the best representation of trophic levels in a food chain?

Answer 31

Pyramids of numbers do not take into account the size of the organisms. A better way of showing the transfer of energy is to use a pyramid of biomass.

Question 32

Why are food chains quite short in general?

Answer 32

Only around 10%of the biomass is passed on from one trophic level to the next.
This is becausearound 90%of the energy islost to the environment.

Question 33

Why does the energy decrease from one trophic level to the next?

Answer 33

• Not every part of the food organism iseaten,e.g. the roots and woody parts of plants or the bones of animals.
• Consumers arenot abletodigestall of the food they ingest, e.g.cellulosein plants, or the fur of animals, so some isegestedasfaeces.
• Energy is lost to the environment in the form ofheatwhen consumersrespire.

Question 34

What is food security?

Answer 34

Food security is having enough food to feed a population.

Question 35

If we grow enough food, will this mean there is food security for everyone?

Answer 35

No. As even if we grow enough food for everyone, many people may still not be able to access that food.

Question 36

If there is not food security what problems can this lead to?

Answer 36

People suffer malnutrition and may starve.

Question 37

Name some of the biological factors that are threatening food security worldwide.

Answer 37

• an increasing birth rate
• changing diets in developed countries
• environmental changes
• cost of agricultural inputs
• conflicts

Question 38

What is sustainable food production?

Answer 38

This means producing food in ways that supply the whole human population and can continue for many years.

Question 39

What is global warming?

Answer 39

Global warming is the increase in the mean temperature of the Earth. The ten hottest years since records began have been in the last 30 years.

Question 40

What is a greenhouse gas?

Answer 40

A greenhouse gas is a gas that absorbs infrared radiation from the Sun so it remains trapped in the Earth’s atmosphere.

Question 41

Why are greenhouse gases important?

Answer 41

They are important to ensure Earth is warm enough for life, however if levels of these gases in the atmosphere increase it leads to an increase in the greenhouse effect which causes the Earth’s average temperature to rise.

Question 42

Name the most common greenhouse gases

Answer 42

Water vapour
Carbon dioxide
Methane
Nitrous oxides
CFCs

Question 43

How have human activities led to increasing levels of carbon dioxide and methane in the atmosphere?

Answer 43

• Carbon dioxide is produced during the combustion of fossil fuel.
• Methane is produced by cattle as they digest grass and released by rice paddy fields.

Question 44

What are some of the consequences of global warming?

Answer 44

• Ocean temperatures increasing, causing melting of polar ice caps / rising sea levels / flooding / coral bleaching.
• Increasing temperatures causing extreme weather like super storms, flooding, droughts.

Question 45

What are some more consequences of global warming?

Answer 45

• Changes in or loss of habitats due to these extreme weather events.
• Decreases in biodiversity as food chains are disrupted and extinction rates increase.

Question 46

Describe why the southern range limit of the ‘Sooty Copper’ Butterfly has moved 60 miles North in recent decades.

Answer 46

Global warming is causing an increase in migration of species to new places due to the need of a particular climate to survive.

This also includes increased spread of pests and disease.

Question 47

What do scientists believe is largely responsible for global warming?

Answer 47

Human activities

Question 48

Describe the ‘Greehouse effect’

Answer 48

1) The Sun emits rays that enter the Earth’s atmosphere.
2) The heat bounces back from the Earth’s surface.
3) Some heat is reflected back out into space.
4) Some heat is absorbed by greenhouse gases and is trapped within the Earth’s atmosphere – this is normal.
5) However, as the levels of greenhouse gases in the atmosphere rise due to human activities the Earth’s average temperature rises beyond normal (an enhanced greenhouse effect), causing global warming.