Our Environment quiz

Which of the following groups contains only biodegradable items?

Which of the following constitutes a food chain?

Which of the following are environment-friendly practices?

The percentage of energy transferred from one trophic level to the next is about:

The ozone layer is found in the:

The chemicals mainly responsible for depletion of the ozone layer are:

Organisms of the first trophic level are:

Which of the following is an artificial ecosystem?

Decomposers break down:

The formula of ozone is:

Why are some substances biodegradable and some non-biodegradable? (2 marks)

Give two ways in which biodegradable substances would affect the environment. (2 marks)

What are trophic levels? Give an example of a food chain and state the different trophic levels in it. (2 marks)

What is the role of decomposers in the ecosystem? (2 marks)

Why is damage to the ozone layer a cause for concern? What steps are being taken to limit this damage? (2 marks)

Why is a lake considered a natural ecosystem while an aquarium is an artificial ecosystem? What must be done to maintain an aquarium? (2 marks)

What will happen if we kill all the organisms in one trophic level? (2 marks)

Will the impact of removing all the organisms in a trophic level be different for different trophic levels? Explain. (2 marks)

Why do producers always occupy the first trophic level in a food chain? (2 marks)

How can you help in reducing the problem of waste disposal? Give two methods. (2 marks)

A food chain in a pond is: phytoplankton -> zooplankton -> small fish -> large fish. If the phytoplankton capture 50,000 kJ of energy, calculate the energy available at each of the other levels by the 10% law, and state the total energy lost from the food chain. (3 marks)

A city of 5 lakh people generates 0.5 kg of solid waste per person per day. Calculate the total waste generated per day in tonnes. If 40% of it can be composted, how many tonnes go to compost each day? (1 tonne = 1000 kg) (3 marks)

In a terrestrial ecosystem, plants capture about 1% of the energy of sunlight falling on their leaves. If 1,000,000 J of sunlight falls on the leaves, how much energy is stored by the plants, and how much would reach a lion that is a secondary consumer in the chain plants -> deer -> lion? (3 marks)

A pesticide enters a food chain with a concentration of 0.02 ppm in grass. If the concentration increases about ten times at each higher trophic level, calculate the concentration in a grasshopper, a frog and a snake in the chain grass -> grasshopper -> frog -> snake. (3 marks)

A school collects 120 kg of waste in a week: 54 kg paper, 36 kg food waste, 18 kg plastic and 12 kg others. Calculate the percentage of each, and state which can be composted and which can be recycled. (3 marks)

Read the passage and answer the questions. A farmer sprayed DDT on his crops to kill insects. Some of the pesticide washed into a nearby pond during the rain. After some years, scientists found that the fish in the pond and the birds that ate the fish had very high levels of DDT, while the water had only a tiny amount. (i) Name the phenomenon described. (ii) Why does the concentration of DDT increase along the food chain? (iii) Suggest two alternatives to chemical pesticides to protect crops. (5 marks)

Read the passage and answer the questions. Ozone (O3) at higher levels of the atmosphere shields the surface of the Earth from ultraviolet radiation from the Sun. However, the amount of ozone began to drop sharply in the 1980s, and an ozone hole was detected over Antarctica. (i) How is ozone formed in the upper atmosphere? (ii) Name the chemicals responsible for this decrease and where they are used. (iii) What harmful effects can UV radiation have on human beings? (5 marks)

Read the passage and answer the questions. In a pond ecosystem, aquatic plants and algae, insect larvae, small fish, frogs and herons live together. Bacteria and fungi are found at the bottom of the pond. (i) Construct a food chain of four trophic levels from these organisms. (ii) What is the role of the bacteria and fungi? (iii) If the frogs were removed, how would the number of insect larvae and herons be affected? (5 marks)

Read the passage and answer the questions. A municipal corporation started a waste segregation drive. Households were given green bins for wet waste and blue bins for dry waste. The wet waste is composted, and the dry waste is sorted for recycling. (i) Which items should go into the green bin? Give two examples. (ii) Which items should go into the blue bin? Give two examples. (iii) Why is segregation of waste at the source important? (5 marks)

Read the passage and answer the questions. In a forest, the energy fixed by plants is 10,000 kJ. Deer eat the plants, and tigers eat the deer. Only a small fraction of the energy is passed on at each step. (i) Calculate the energy available to the deer and to the tigers. (ii) Why is there always a smaller number of tigers than deer? (iii) Where does the rest of the energy go at each level? (5 marks)

What is an ecosystem? Explain its components, giving examples of natural and artificial ecosystems. Draw a labelled diagram of a pond ecosystem showing producers, consumers and decomposers. (6 marks)

What are food chains and food webs? Explain with a labelled diagram of a food web. Describe the 10% law of energy transfer, and explain why the flow of energy is unidirectional and why the number of trophic levels is limited. (6 marks)

Explain biological magnification with a labelled diagram of a food chain showing increasing concentration of a pesticide at each level. Why are human beings most affected? Suggest ways to reduce the problem. (6 marks)

How is the ozone layer formed, and why is it important? Explain with a diagram the role of CFCs in ozone depletion. What international steps have been taken to protect the ozone layer? (6 marks)

Classify the following wastes into biodegradable and non-biodegradable: vegetable peels, plastic bottles, newspaper, glass, cotton cloth, aluminium foil, leaves and polythene. Explain the problems caused by non-biodegradable wastes and describe methods of waste management such as composting, recycling and reducing. Draw a flow chart of the waste management process. (6 marks)