Define the following terms and give two examples in each case.

(a) Autotrophs

(b) Consumers

(c) Food chain

(d) Symbiosis

(e) Parasitism

(f) Predation

(a) Autotrophs — Autotrophs are organisms that produce their own food through Photosynthesis using simple substances like Carbon dioxide and Water in the presence of Sunlight. They come at the beginning of the food chain. Plants like grass, bushes, trees, etc. are examples of Autotrophs.

(b) Consumers — Consumers are organisms that depend on producers for food. Consumers can be primary, secondary, or tertiary. Primary consumers eat plants or plant products. Example: Grasshopper, Rat etc. Secondary consumers feed on primary consumers. Examples include Frog, Lizard, etc. Tertiary consumers feed on secondary consumers. Example : Eagle, Fox, etc.

(c) Food chain — Food chain is the linear sequence of organisms in which each organism eats the lower member and is itself eaten by the next higher member. Two examples of food chain are:

1. Grass (Producer) → Goat (Primary Consumer) → Man (Secondary consumer)
2. Grass (Producer) → Grasshopper (Primary Consumer) → Frog (Secondary Consumer) → Snake (Tertiary Consumer).

(d) Symbiosis — Symbiosis is defined as a relationship or interaction in which both the interacting species are benefitted. Two examples of Symbiotic relationship are:

1. Plants need the help of animals for pollinating their flowers and dispersing their seeds. Animals are paid fees by the plants in the form of juicy and nutritious fruits.
2. Lichens is another example in which a fungus and a photosynthetic alga live in a symbiotic relationship. Algae provides food and nourishment to fungus while fungus protects the algae from getting damaged by ultraviolet rays by forming a protective shell.

(e) Parasitism — In parasitism, one partner (the parasite) receives an advantage while the other (the host) is at a loss. The parasites harm the host reducing the revival, growth and reproduction of the host. Two examples of Parasitism are:

1. The malarial parasite, Plasmodium needs an intermediate host (vector) — a mosquito to spread to other hosts.
2. Human liver fluke depends on two intermediate hosts (a snail and a fish) to complete its life-cycle.

(f) Predation — When an animal catches and kills other organisms for food, it is termed Predation. All animals in food chain fall under the category of Predators regardless they be herbivores. Two examples of Predation are:

1. Tiger hunting and eating deer.
2. House sparrow eating any seed.