Which of the following pyramids can never be inverted in any ecosystem?
1. Pyramid of numbers
2. Pyramid of biomass
3. Pyramid of energy
4. All ecological pyramids can be inverted

In an ecological pyramid, the saprotrophs:
1. are primary producers
2. can be at any trophic level
3. are not given any place
4. are kept with apex predators

Ecological succession is:
1. gradual and predictable
2. gradual and unpredictable
3. sudden and predictable
4. sudden and unpredictable

The entire sequence of communities that successively change in a given area are called:
1. Taxa
2. Seres
3. Pioneers
4. Climax

Ecological succession has paralleled:
1. Glaciations
2. Mass extinctions
3. Genetic drifts
4. Evolution

In which of the following instances would an ecological succession regarded as secondary?
1. Newly cooled lava
2. Bare rock
3. Newly created pond
4. Abandoned farmland

Identify the correct statements regarding ecological succession:

1. Only I and II
2. Only I and III
3. Only II and III
4. I, II and III

Ecological succession leads to mesic conditions in: 

1. Both I and II
2. Only I
3. Only II
4. Neither I nor II

In primary succession in water, the pioneers are normally:
1. Lichens
2. Mosses
3. Phytoplankton
4. Submerged rooted plants

Lichens are very useful pioneers in succession on a bare rock, especially because:
1. they are sensitive to environmental pollution
2. they have various modes of nutrition
3. they help in the formation of soil
4. they would prevent colonization by parasites