Nutrient Cycles

What is the role of decomposers in nutrient cycles?

• Decomposers break down dead organic matter, returning nutrients to the soil and making them available for plants.

• Decomposers convert sunlight into energy for plants.

• Decomposers produce oxygen as a byproduct of decomposition.

• Decomposers create new organic matter from inorganic substances.

How do animals contribute to the carbon cycle?

• By giving off carbon dioxide through respiration, which is then used by plants for photosynthesis.

• By consuming plants and converting them into energy without any gas exchange.

• By storing carbon in their bodies and releasing it only when they die.

• By producing oxygen as a byproduct of their metabolic processes.

How does deforestation impact the carbon cycle?

• Deforestation decreases carbon dioxide levels in the atmosphere by increasing the number of trees that can absorb CO₂ during photosynthesis.

• Deforestation has no effect on the carbon cycle as trees are not significant in CO₂ absorption.

• Deforestation increases carbon dioxide levels in the atmosphere by reducing the number of trees that can absorb CO₂ during photosynthesis.

• Deforestation helps in maintaining the carbon cycle by promoting soil carbon storage.

What is the difference between nitrification and denitrification?

• Nitrification converts ammonia into nitrogen gas, while denitrification converts nitrogen gas into ammonia.

• Nitrification is the process of converting ammonia into nitrites and then nitrates, while denitrification is the conversion of nitrates back into nitrogen gas, releasing it into the atmosphere.

• Nitrification and denitrification are the same processes that convert nitrates into ammonia.

• Nitrification is the process of converting nitrites into ammonia, while denitrification is the conversion of ammonia into nitrates.

What role do plants play in the carbon cycle?

• Plants absorb carbon dioxide from the atmosphere during photosynthesis, converting it into glucose and releasing oxygen.

• Plants release carbon dioxide into the atmosphere during respiration only.

• Plants do not play a significant role in the carbon cycle.

• Plants absorb oxygen from the atmosphere and release carbon dioxide.

Why can't plants use atmospheric nitrogen directly?

• Because it exists as a diatomic molecule (N₂) that is not reactive.

• Because it is too abundant in the atmosphere for plants to absorb.

• Because it is only available in liquid form in the soil.

• Because plants do not have the necessary enzymes to process it.

What is the nitrogen cycle?

• A process that converts nitrogen into oxygen for plant use.

• The process by which nitrogen is converted between its various chemical forms, including nitrogen fixation, nitrification, denitrification, and ammonification, allowing nitrogen to be utilised by living organisms.

• A method of storing nitrogen in the soil to prevent leaching.

• The cycle of nitrogen in the atmosphere that affects weather patterns.

What is the significance of the phosphorus cycle?

• It is essential for the growth of plants and animals, as phosphorus is a key component of DNA, RNA, and ATP.

• It helps in the formation of ozone in the atmosphere.

• It regulates the Earth's temperature by absorbing heat.

• It is important for the nitrogen fixation process in soil.

What is one major way carbon dioxide is released back into the atmosphere?

• Through the process of photosynthesis.

• By the burning of fossil fuels.

• Via volcanic eruptions.

• During the decomposition of organic matter.

What is the water cycle?

• The water cycle is the continuous movement of water on, above, and below the surface of the Earth, involving processes like evaporation, condensation, precipitation, and infiltration.

• The water cycle is the process of water being stored in lakes and rivers only.

• The water cycle refers to the way water is used in industrial processes.

• The water cycle is the method by which water is filtered and purified for drinking.