English Medium Class 10 - CBSE Question Bank Solutions

If the energy available at the producer level in a food chain is 150 J, how much energy will be transferred to : tertiary consumer?
(a) 15 J
(b) 10 J
(c) 1.50 J
(d) 0.15 J

In addition to wheat plants, a crop field ecosystem has organisms such as snake, peacock, eagle and mice. If the wheat plants are sprayed with pesticides periodically, which of the following will have the minimum concentration of pesticides in the body?
(a) snake
(b) eagle
(c) mice
(d) peacock

The ten per cent law is associated with
(a) transfer of energy from various trophic levels to decomposers in a food chain
(b) transfer of ATP energy into muscular energy
(c) transfer of chemical energy from one organism to another
(d) transfer of sun's energy to the organisms called producers.

The harmful chemical which is accumulating in human beings through food chain is :
(a) benzenehexachloride
(b) dichlorodiphenyltrichloroethane
(c) chlorofluorocarbon
(d) abscisic acid

The surface of water in a lake appears green due to a layer of tiny free-floating organisms X on its surface. The lake water also contains organisms like water beetle, fish and tadpole. The sun shines over the lake water and provides energy for the functioning of this lake ecosystem.
(a) What could organisms X be?
(b) Write a food chain comprising of all the four organisms mentioned.
(c) What is the general name of the food chains like the one written above?
(d) Name (i) secondary consumer (ii) producer (iii) tertiary consumer, and (iv) primary consumer, in the above food chain.
(e) If the tertiary consumer gets 0.2 J of energy from the secondary consumer, then how much energy was radiated by the sun to the producer?

A forest ecosystem having a lot of green plants has some foxes, lions and rabbits in it.
(a) Write a food chain comprising all the four organisms mentioned above.
(b) Name (i) one herbivore, and (ii) two carnivores, in this food chain.
(c) Name the link which is a predator as well as a prey.
(d) Name (i) second trophic level, and (ii) third trophic level.
(e) Which link of this food chain can feed on second trophic level as well as third trophic level, independently?
(f) If the sun provides 1000 J of energy to the plants, then how much energy will be transferred to fox through the food chain.

1. In which organisms the pesticides enter from the polluted water? What is this level of organisms known as?
2. Which organism will have the maximum amount of pesticides accumulated through the food chain? What is this process known as?
3. Write the food chain comprising all the organisms mentioned above.
4. Which other organism you could write in place of bird in the above food chain?

A food chain consists of fish, larvae, phytoplanktons and birds. The level of pesticides in water in which the fish, larvae and phytoplanktons live is quite high.                                             

Which organism will have the maximum amount of pesticides accumulated through the food chain? What is this process known as?

A food chain consists of fish, larvae, phytoplanktons and birds. The level of pesticides in water in which the fish, larvae and phytoplanktons live is quite high.

Write the food chain comprising all the organisms mentioned above.

A food chain consists of fish, larvae, phytoplanktons and birds. The level of pesticides in water in which the fish, larvae and phytoplanktons live is quite high.

Which other organism you could write in place of bird in the above food chain?

Your mother always thought that fruit juices are very healthy for everyone. One day she read in the newspaper that some brands of fruit juices in the market have been found to contain certain level of pesticides in them. She got worried as pesticides are injurious to our health.
(a) How would you explain to your mother about fruit juices getting contaminated with pesticides?
(b) It is said that when these harmful pesticides enter our body as well as in the bodies of other organisms they get accumulated and beyond a limit cause harm and damage to our organs. Name the phenomenon and write about it.

"Energy flow in food chains is always unidirectional". Justify this statement. Explain how the pesticides enter a food chain and subsequently get into our body.

1. Why is the maximum concentration of pesticides found in human beings?  (1)
2. Give one method which could be applied to reduce our intake of pesticides through food to some extent.  (1)
3. Various steps in a food chain represent:  (1) 
   1. Food web
   2. Trophic level
   3. Ecosystem
   4. Biomagnification
4. With regard to various food chains operating in an ecosystem, man is a:   (1)
   1. Consumer
   2. Producer
   3. Producer and consumer
   4. Producer and decomposer

What are decomposers? What will be the consequence if the decomposers are completely eradicated from an ecosystem? Give justification in support of your answer.

Which of the following is not considered as crystalline allotrope of carbon?

Which of the following is not an allotropic form of carbon?

How many number of carbon atoms are joined in a spherical molecule of buckminsterfullerene?

In a given food chain if the amount of energy at the fourth trophic level is 6 kJ, what will be the energy available at the producer level?

We should reduce the use of the plastic bags, bottles etc. because ______.

Green plants utilize ______ percent of sun’s energy to prepare their food by the process of photosynthesis.