Question

In a food chain, deer are eaten by lions and deer eat vegetation . Which one of the statements given is true?
(P) Lion is a second order consumer and deer is a first order consumer.
(Q) Lions are predators and deer is prey.
(R) Lion is first order consumer and deer is second order consumer.
(S) Lion is third order consumer and deer is second order consumer.
(A) Only (P) and (Q)
(B) Only (Q) and (R)
(C) Only (P) and (S)
(D) Only (P) and (R)

Answer 1

Hint: In the ecosystem , green plants are generally called producers as they prepare their own food with the help of photosynthesis which become the food source for other organisms.

Complete answer:
So generally, Autotrophs are producers . While the organism which depends on autotrophs for their food and consumes the matters built up by the primary producers are called heterotrophs. On the basis of consuming the food, heterotrophs are grouped into three categories:-
i) Holozoic: Such organisms consume their food through the mouth . Example: Herbivores, Carnivores, Omnivores. Herbivores are called Primary consumers or first order consumers because they feed on producers directly. Example: deer, cow etc.
Carnivores and Omnivores are the secondary consumers or second order consumers which feed on primary consumers. Example: Lion, snake , tiger etc.
Top carnivores who feed on both primary and secondary consumers are called tertiary consumers. Example: Hawk, vultures etc.
The animal who feeds upon another animal is called predator and the later is called prey.
ii) Saprophytes: Such organisms take their food in the solution form from dead or decaying tissues of plants and animals. Example: Fungi
iii) Parasite: Such an organism lives on the living protoplasm of another organism. Example: Lice etc.
From the above discussion it is clear that deer belong to the first order consumer and lion belongs to the second order consumer. And as deer feed upon deer and hence it is a predator while deer is prey.

Hence the correct answer is OPTION(A)

Note: The saprophytes and the parasites are also called decomposers/ Reducers/ Transformers/ Saprotrophs or Osmotrophs. The decomposers decompose the dead bodies of producers and consumers by feeding upon them. The transformers transform the complex compounds into basic inorganic forms. Thus due to decomposers and transformers the basic chemical substances become available again and again to be utilised by the producers.