Advertisements
Advertisements
प्रश्न
What percentage of sun's energy falling on the leaves of green plants is utilised by the plants in the process of photosynthesis and stored as chemical energy of food?
(a) 99 per cent
(b) 10 per cent
(c) 1 per cent
(d) 20 per cent
Advertisements
उत्तर
1 per cent
Only one per cent of the sun's energy falling on the leaves of green plants is utilised by the plants in the process of photosynthesis and stored as the chemical energy of food.
APPEARS IN
संबंधित प्रश्न
Give an example of a four step food chain operating in grassland. Name the secondary consumer in this food chain
Draw the food chain with four trophic levels.
Write down a food chain with five links in it.
Write one or two word for the following statement/definition :
Each level of food chain where transfer of energy takes place
In a food chain, the initial organism is usually :
(a) photosynthetic
(b) herbivore
(c) saprophytic
(d) parasitic
In a food chain, the third trophic level is always occupied by :
(a) carnivores
(b) herbivores
(c) decomposers
(d) producers
The sea water contains water beetles, tadpole, fish and weeds.
Which organism is a secondary consumer?
Some hunters are roaming in the plush green forest of Africa. They spot a deer and kill it. They decide to roast the deer there and then and eat it. When the hunters had just finished enjoying the feast of roasted deer, a lion attacks them. The lion kills one of the hunters and eats his flesh.
(a) write a food chain which provides food to lion in this case.
(b) Which animal (other than deer) the lion could look for food if he did not get the hunter as prey?
(c) Which other animal in the forest could have been in place of lion?
(d) How does the above food chain differ form the food chain such as : plants → goat → man?
In a food chain consisting of grass, frog, bird and insects, where will the concentration of the harmful chemicals be maximum?
Name two predators of snakes in a food web operating in a forest ecosystem.
Explain why, the flow of energy in the ecosystem is said to be unidirectional.
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 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 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?
Which of the following is an autotroph?
What are autotrophs?
In the following food chain, vertical arrows indicate the energy lost to the environment and horizontal arrows indicate energy transferred to the next trophic level. Which one of the three vertical arrows (A, C and E) and which one of the two horizontal arrows (B and D) will represent more energy transfer? Give reason for your answer.

A food chain in a forest ecosystem
Use of several pesticides which results in excessive accumulation of pesticides in rivers of ponds, is a matter of deep concern. Justify this statement.
Study the picture given below showing three food chains (a), (b) and (c) and answer the following questions:

- Name the type of ecosystems that exist in food chains (b) and (c).
- The first trophic level in all food chains is producers. Why? What percentage of solar energy do these producers capture for their use?
- Why are the arrows shown in the diagram in one direction only and not vice versa? Justify.
