Solved Questions on Food Chain, Food Web and Life Cycle
1. How do nymphs differ from adult cockroaches?
a) Nymphs are smaller, wingless versions of adult cockroaches.
b) Nymphs have wings and reproductive organs.
c) Nymphs are brown or black in colour.
d) Nymphs can live for several years.
Answer: a) During the nymph stage, cockroaches are smaller in size compared to adults and do not have fully developed wings or reproductive organs.
2. An experiment is conducted to observe the life cycle of a butterfly. What is the expected order of the stages to be observed?
a) Egg, pupa, caterpillar, adult
b) Pupa, egg, larva, adult
c) Larva, pupa, egg, adult
d) Egg, larva, pupa, adult
Answer:d) The expected order of the stages to be observed in the life cycle of a butterfly is: Egg, larva (caterpillar), pupa (chrysalis), and adult butterfly.
3. Which of the following is a tertiary consumer in a forest food web?
a) Rabbit
b) Hawk
c) Grasshopper
d) Mouse
Answer: b) In a forest food web, a tertiary consumer refers to an organism that feeds on secondary consumers. Among the given options, the hawk is the most likely candidate for a tertiary consumer.
4. Complete the following marine food chain by selecting the suitable option.
a) X: Shark, Y: Fish
b) X: Fish, Y: Shark
c) X: Whale, Y: Shark
d) X: Fish, Y: Crab
Answer: b) Seaweed serves as a primary producer in the food chain, while squids are considered primary consumers that feed on seaweed. The missing link is the organism that feeds on squids, and in this case, it is a fish. Finally, the top predator in this food chain is a shark, which prey on the fish.
5. Match the organisms with their appropriate levels in a food chain.
| Column I |
Column II |
| 1. Owl |
A) Primary Consumer |
| 2. Mushroom |
B) Producer |
| 3. Horse |
C) Secondary consumer |
| 4. Grass |
D) Decomposer |
a) 1:A, 2:D, 3:C, 4:B
b) 1:C, 2:B, 3:A, 4:D
c) 1:C, 2:D, 3:A, 4:B
d) 1:A, 2:C, 3:D, 4:B
Answer: c) Owl: Secondary Consumer
Mushroom: Decomposer
Horse: Primary Consumer
Grass: Producer
FAQs
1. What is a decomposer in a food chain?
Bacteria and fungi are examples of decomposers, transforming decaying materials, ancient plants, and animals into simpler forms. They complete the life cycle by providing essential nutrients to other living things. Decomposers maintain the health of ecosystems, recycle nutrients, and sustain the food chain.
2. What is grassland food chain?
In the grassland food chain, grass is the producer, eaten by grasshoppers (first trophic level). Frogs (second trophic level) eat grasshoppers, while snakes (fourth trophic level) eat the frogs. Finally, vultures or eagles (fifth trophic level) prey on the snakes.
3. How Do Changes in a Food Web Affect the Ecosystem?
The ecosystem as a whole may be impacted by modifications to any one component of the food chain. For example, the extinction of a species might disturb the balance and affect other creatures within the web.
4. What is the Difference Between a Food Chain and a Food Web?
A food web is a closely connected network of several food chains, whereas a food chain is a simple straight order.
5. Can Humans Affect Food Chains?
Yes, human activity may affect the food chain. The availability of food for different species in the food chain can be affected by ecological disruption caused by pollution, deforestation, and overfishing.
