Distinguish between
$(a)$ Grazing food chain and detritus food chain
$(b)$ Production and decomposition
$(a)$ Grazing food chain and detritus food chain
Grazing food chain | Detritus food chain |
$1$. In this food chain, energy is derived from the Sun. | $1$. In this food chain, energy comes from organic matter (or detritus) generated in trophic levels of the grazing food chain. |
$2$. It begins with producers, present at the first trophic level. The plant biomass is then eaten by herbivores, which in turn are consumed by a variety of carnivores. | $2$. It begins with detritus such as dead bodies of animals or fallen leaves, which are then eaten by decomposers or detritivores. These detritivores are in turn consumed by their predators. |
$3$. This food chain is usually large. | $3$. It is usually smaller as compared to the grazing food chain. |
$(b)$ Production and decomposition
Production | Decomposition |
$1$. It is the rate of producing organic matter (food) by producers. | $1$. It is the process of breaking down of complex organic matter or biomass from the body of dead plants and animals with the help of decomposers into organic raw material such as $\mathrm{CO}_{2}, \mathrm{H}_{2} \mathrm{O},$ and other nutrients. |
$2$. It depends on the photosynthetic capacity of the producers. | $2$. It occurs with the help of decomposers. |
$3$. Sunlight is required by plants for primary production. | $3$. Sunlight is not required for decomposition by decomposers |
Which of the following is false?
Assertion : A network of food chains existing together in an ecosystem is known as food web.
Reason : An animal like kite cannot be a part of a food web.
Which of the following are called key industry animals?
$...A...$ is required for higher primary productivity. $...B...$ have the lowest primary productivity as the soil is deficient in moisture.
Choose the correct option for $\mathrm{A}$ and $\mathrm{B}$