4d-Human influences on the environment

Question 1

Q: How do human activities impact ecosystems?

Answer 1

Human activities such as pollution, deforestation, climate change, and habitat destruction disrupt ecosystems, reduce biodiversity, and affect global climate patterns.

Question 2

What are the main types of pollution caused by human activities?

Answer 2

Air Pollution: Caused by burning fossil fuels, releasing carbon dioxide (CO₂), sulfur dioxide (SO₂), and nitrogen oxides (NOₓ), which contribute to global warming and acid rain.

Water Pollution: Caused by industrial waste, agricultural fertilizers, and sewage, leading to water contamination and eutrophication.

Land Pollution: Caused by pesticides, plastics, and waste disposal, which can harm soil quality and wildlife.

Question 3

What is eutrophication, and how does it affect aquatic ecosystems?

Answer 3

Eutrophication is caused by excess nutrients (mainly nitrates and phosphates) from fertilizers entering water bodies, leading to:

Rapid algae growth (algal bloom), which blocks sunlight.

Death of aquatic plants due to lack of light.

Bacteria decompose dead plants, using up oxygen.

Oxygen depletion causes fish and other aquatic life to die.

Question 4

What are the effects of deforestation on ecosystems?

Answer 4

Reduced Biodiversity: Loss of habitats and extinction of species.

Increased CO₂ Levels: Reduced photosynthesis means less CO₂ absorption, contributing to global warming.

Soil Erosion: Loss of tree roots leads to soil erosion and reduced soil fertility.

Question 5

How does human activity contribute to climate change?

Answer 5

Burning fossil fuels, deforestation, and industrial processes increase greenhouse gases like CO₂, methane (CH₄), and nitrous oxide (N₂O), trapping heat in the atmosphere and causing global warming.

Question 6

What are the effects of climate change?

Answer 6

Rising temperatures and sea levels

Extreme weather events (storms, droughts, floods)

Habitat loss and species extinction

Disruption of food chains and ecosystems

Question 7

Practical: Investigating the Effects of Pollution

Investigating the Effect of Fertilizers on Plant Growth:

Answer 7

Method: Grow plants in soil with different fertilizer concentrations and measure growth.

Result: Excess fertilizer may increase growth initially but can cause nutrient imbalance or leaching.

Question 8

Practical: Investigating the Effects of Pollution
Investigating the Effect of Acid Rain on Plant Growth:

Answer 8

Method: Expose plants to water with different pH levels and observe growth.

Result: Lower pH (more acidic) reduces plant growth and damages leaves.