Energy Flow

Q.

What is ten per cent law? Explain with an example.

Q.

Each level in a food chain is called a _________.

Q.

(a) With the help of a flow diagram, describe how energy from the sun flows through various trophic levels.

(b) Explain why the flow of energy in the ecosystem is said to be unidirectional.

Q. If the producers has 100 kcal of energy, how much energy in kcal will be available for tertiary consumers?

1. 0.1

Q.

What trophic level are decomposers?

Q.

(a) Name and state the law given by Lindeman which tell us how much energy entering a particular trophic level of organisms is available for transfer to the next higher trophic level.

(b) How much energy will be available to hawks in the food chain comprising hawk, snake, paddy and mice, if 10, 000 J of energy is available to paddy from the sun?

Q.

What percentage of the solar energy is trapped and utilised by the plants?

Q.

The flow of energy in an ecosystem is always :

(a) unidirectional (b) bidirectional (c) cyclic (d) multidirectional

Q.

If a grasshopper is eaten by a frog, then the energy transfer will be from

1. (a) Producer to decomposer

2. (b) Producer to primary consumer

3. (c) Primary consumer to secondary consumer

4. (d) Secondary consumer to primary consumer

Q.

The true end of any food chain is?

Q.

Which of the following gets the minimum energy through the food chain in an ecosystem?

(a) carnivore (b) large carnivore (c) producer (d) herbivore

Q. The flow of energy is unidirectional in a pyramid.

1. True
2. False

Q.

The surface of the 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?

Q.

Explain Raymond Lindemanns 10% law.

Q.

If 5 joules of energy is available at producer level (plants), then how much energy will be transferred to the lion in the following food chain ?

$Plants\to Goat\to Lion$

Q.

What is the driving energy of the hydrologic cycle?

1. Nuclear energy

2. Tidal energy

3. Thermal energy

4. Solar energy

Q.

Where does all the energy in living organisms originate from?

Q.

In the food chain given below, if the amount of energy available at the fourth trophic level is 5 kJ, what was the energy available at the producer level?

$Grass\to Grasshopper\to Frog\to Snake\to Hawk$

(a) 500 kJ (b) 50 kJ (c) 5000 kJ (d) 5 kJ

Q.

If the energy transferred to a tertiary consumer in a food chain is 10 J, how much energy was available to the primary consumer?

(a) 100 J (b) 500 J (c) 1000 J (d) 0.15 J

Q.

Question 10
The flow of energy in an ecosystem is always

(a) unidirectional
(b) bidirectional
(c) multi directional
(d) no specific direction

Q.

What percentage of sun's energy falling on the leaves of green plants are 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

Q.

If the energy available at the producer level in a food chain is 150 J, how much energy will be transferred to the tertiary consumer?

(a) 15 J (b) 10 J (c) 1.50 J (d) 0.15 J

Q.

Question 8
In an ecosystem, the 10% of the energy available to the next trophic level is in the form of

(a) heat energy
(b) light energy
(c) chemical energy
(d) mechanical energy

Q.

What provides the energy which then flows through a food chain?

(a) glucose (b) oxygen (c) respiration (d) sunlight

Q.

(a) Explain why a food chain usually cannot have more than three or four steps.

(b) Calculate the amount of energy that will be available to big fish in the following food chain, if 10, 000 J of energy is available to small algae from the sun :

$Smallalgae\to Zooplankton\to Fish\to Bigfish$

Q.

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 from one organism to another

(c) transfer of chemical energy from one organism to another

(d) transfer of sun's energy to the organisms called producers.

Q.

State whether the following statement is true or false :

Only 10 percent of the light energy given by the sun is available for transfer at each higher trophic level in a food chain.

Q.

Most of the water surface of a lake is covered with algae. This alga is part of the food chain which also includes small fish, bird, larvae and big fish. Which of the following will obtain the maximum energy?

(a) big fish (b) bird (c) larvae (d) small fish

Q.

(i) How do plants trap solar energy and convert it into food energy?

Q. What is the major reason for a food chain to have limited trophic levels of only $3-4$?

1. There is lot of competition for survival.
2. Energy loss at each level.
3. Biomass at each level varies.
4. Population at each trophic level increases.