Which interaction between species is characterised by both species benefiting from the relationship?

A. Competition

B. Predation

C. Mutualism

D. Parasitism

What is the primary role of decomposers in ecosystems?

A. To consume producers

B. To recycle nutrients

C. To reduce energy flow

D. To increase biomass

Why is energy lost as heat between trophic levels?

A. Due to photosynthesis

B. Due to cellular respiration

C. Due to competition

D. Due to predation

Which factor primarily determines the length of food chains in ecosystems?

A. The number of predators

B. The availability of light

C. Energy limitations

D. The rate of decomposition

What is the role of autotrophs in converting carbon dioxide into carbohydrates?

A. Decomposition

B. Respiration

C. Photosynthesis

D. Predation

a) Define symbiosis and describe one example of a symbiotic relationship, explaining how it impacts community structure. [3]

b) Explain the role of decomposers in energy flow within an ecosystem and how they contribute to nutrient cycling. [3]

a) Discuss how competition between species can influence community structure, providing a specific example. [3]

b) Describe the carbon cycle and explain the role of autotrophs in this cycle. [3]

a) Explain the concept of trophic levels and how energy is transferred between these levels in an ecosystem. [3]

b) Discuss the significance of methane production by methanogenic archaeans and its impact on the atmosphere. [3]

a) Explain the difference between species richness and species evenness in measuring biodiversity. [3]

b) Discuss how invasive species can pose a threat to biodiversity, providing a real-world example. [4]

c) Outline the nitrogen cycle and identify the role of bacteria in this cycle. [3]

a) Describe the concept of carrying capacity in relation to logistic growth. [3]

b) Explain how energy limitations affect the length of food chains in ecosystems. [4]

c) Discuss the water cycle and the importance of this cycle in ecosystems. [3]

Which of the following is not a major nutrient cycle in ecosystems?

A. Water cycle

B. Carbon cycle

C. Nitrogen cycle

D. Sulphur cycle

How does methane production by methanogenic archaeans in anaerobic conditions impact the atmosphere?

A. It reduces greenhouse gases

B. It increases oxygen levels

C. It contributes to global warming

D. It decreases atmospheric pressure

Which interaction between species results in one species benefiting at the expense of the other?

A. Mutualism

B. Commensalism

C. Parasitism

D. Symbiosis

What is the significance of carbon dioxide in aquatic ecosystems?

A. It decreases pH levels

B. It is a source of energy for aquatic plants

C. It is produced by respiration and diffused from organisms

D. All of the above

Which of the following best describes the impact of competition on community structure?

A. It leads to mutual benefit

B. It results in niche differentiation

C. It increases species diversity

D. It promotes symbiosis

a) Discuss the impact of climate change on community structure and interactions between species. [4]

b) Explain the role of autotrophs in converting carbon dioxide into carbohydrates and its significance in ecosystems. [3]

c) How does methane production by methanogenic archaeans in anaerobic conditions impact the atmosphere? [3]

a) Explain the difference between exponential and logistic population growth models. [3]

b) Discuss the factors determining the length of food chains in ecosystems. [4]

c) Describe the phosphorus cycle and explain why it is essential for living organisms. [3]

a) Define symbiosis and describe the three main types of symbiotic relationships. [4]

b) Explain the process of primary production and its importance in ecosystems. [3]

c) Discuss the role of decomposers in energy flow within an ecosystem. [3]

d) How do human activities contribute to increased levels of carbon dioxide in the atmosphere? [4]

a) Discuss the impact of predation on community structure. Provide an example. [4]

b) Explain the concept of carrying capacity and how it affects population growth. [3]

c) Outline the carbon cycle and identify the role of living organisms in this cycle. [4]

d) Discuss the strategies for mitigating climate change, focusing on enhancing carbon sinks. [3]

a) Describe the different types of interactions between species and discuss their impact on community structure. [4]

b) How does energy limitation affect the biomass of different trophic levels in an ecosystem? [3]

c) Explain the significance of nitrogen in living organisms and outline the nitrogen cycle. [4]

d) Discuss the impact of methane production by methanogenic archaeans on the atmosphere. [3]