Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R).

Assertion (A):	We generally undervalue the magnitude of ecosystem services that benefits us.
Reason (R):	We do not attach a monetary value to the services of natural ecosystems.

In the light of the above statements, choose the most appropriate answer from the options given below:

1.	Both (A) and (R) are true and (R) is the correct explanation of (A).
2.	Both (A) and (R) are true but (R) is not the correct explanation of (A).
3.	(A) is true but (R) is false.
4.	Both (A) and (R) are false.

1. If both the assertion and the reason are true and the reason is a correct explanation of the assertion
2. If both the assertion and reason are true but the reason is not a correct explanation of the assertion
3. If the assertion is true but the reason is false
4. If both the assertion and reason are false

Detritus is
1. Dead raw material for decomposition.
2. Partially decomposed organic matter.
3. Dead remains of animals & plants.
4. Both 1 and 3

In most ecosystems, all the pyramids of number, energy and biomass are upright. It indicates that
(a) Producers are more in number and biomass than the herbivores.
(b) Herbivores are less in number and biomass than the carnivores.
(c) Energy at a lower tropic level is always more than at a higher level.
Choose the correct option.
1. Only (a) is correct.
2. Only (b) is correct.
3. Both (a) and (c) are correct.
4. Both (b) and (c) are correct.

Addition of which of the following can prevent leaching of minerals?
1. humus
2. mycorrhizae
3. rhizobia
4. calcium

Given below is a hypothetical pyramid of energy. The amount of energy left at the level of secondary consumers would approximately be:
 

What type of ecological pyramid would be obtained with the following data? 

Secondary consumer: 120 g 

Primary consumer: 60 g 

Primary producer: 10 g

1. Inverted pyramid of biomass

2. Pyramid of energy

3. Upright pyramid of numbers

4. Upright pyramid of biomass

The primary producers of the deep-sea hydrothermal vent ecosystem are:
1. green algae
2. chemosynthetic bacteria
3. blue-green algae
4. coral reefs

Presence of plants arranged into well-defined vertical layers depending on their height can be seen best in:

1. Tropical Rain Forest

2. Grassland

3. Temperate Forest

4. Tropical Savannah

In which of the following, do both pairs have the correct combination?