What is the source of energy for all ecosystems on Earth?
a. Sun
b. Hydrothermal vents
c. Lava
d. Both ‘a’ and ‘b’

What percentage of the incident solar radiation is photosynthetically active radiation (PAR)?
a. 50%
b. Less than 50%
c. More than 50%
d.10%

What proportion of the PAR (photosynthetically active radiation) is captured by plants?
a. 1 - 10%
b. 2 - 10%
c. 5 - 15%
d. 5 - 25%

Which of the following statement is incorrect?
a. Ecosystems are exempted from the Second Law of thermodynamics.
b. An ecosystem has a tendency toward increasing disorderliness.
c. Flow of energy is unidirectional from the sun to producers and then to consumers.
d. All organisms are dependent for their food on producers, either directly or indirectly

Which are the primary consumers in a grazing food chain?
a. Carnivores
b. Herbivores
c. Detrivores
d. Omnivores

What do secondary carnivores refer to?
a. Animals at second trophic level
b. Those animals that depend on the herbivores for food
c. Those animals that depend on the primary carnivores for food
d. Those animals that depend on the secondary herbivores for food

The detritus food chain (DFC) begins with________________. It is made up of decomposers which are ______________organisms, mainly________________. They meet their energy and nutrient requirements by degrading ______________.
a. detritus, heterotrophic, earthworm and dead organic matter.
b. dead organic matter, heterotrophic, fungi and bacteria, dead organic matter.
c. dead organic matter, autotrophic, fungi and plants, dead organic matter.
d. grass, heterotrophic, fungi and bacteria, dead organic matter.

What is the major conduit for energy flow in an aquatic ecosystem?
a. Grazing food chain
b. Detritus food chain
c. Sun
d. Hydrothermal vents

Identify the odd one out.
a. Cockroach
b. Crow
c. Humans
d. Goat

“Detritus food chain may be connected with the grazing food chain at some levels” this is evident from
(i). Some of the organisms of DFC are prey to the GFC animals
(ii). In a natural ecosystem, some animals like cockroaches, crows, etc., are omnivores.
(iii). Some of the organisms of GFC are facultative decomposers
a. i and iii
b. i and ii
c. ii and iii
d. i only