Which one among the following constitute a food chain ?
- A.Grass, Fish and Goat
- B.Grass, Insects and Frog
- C.Goat, Cow and Elephant
- D.Tiger, Lion and Grass
Correct answer
Explanation
The correct answer is B, Grass, Insects and Frog. It is the only set in which each organism eats the one before it, so energy passes along a single feeding line.
A food chain begins with a producer, a green plant that makes food by photosynthesis. Herbivores that eat the plant are primary consumers, and the animals that eat them are secondary consumers. In option B, grass is the producer, grasshoppers and other insects feed on grass, and the frog catches and eats the insects. Each link is one trophic level, and only about ten per cent of the energy passes from one level to the next.
Option A is wrong because a goat does not eat fish. Option C is wrong because goat, cow and elephant are all herbivores, and none of them eats another. Option D is wrong because tigers and lions do not eat grass, and a lion does not prey on a tiger.
Exam tip: Producer, then herbivore, then carnivore; grass, insect, frog, snake, eagle is the textbook chain.
Practice Questions
View allWhich of the following is/are renewable source(s) of energy? 1. Fossil fuel 2. Biofuel 3. Uranium 4. Hydropower Select the correct answer using the code given below.
- A.2 only
- B.3 and 4
- C.1 and 3
- D.2 and 4
Show answer
Biofuel and hydropower are renewable because nature replaces them within a human lifetime, while fossil fuels and uranium are not.
Read the full explanation →Which one of the following is NOT decomposed by bacterial action ?
- A.Vegetable remains
- B.Plastic materials
- C.Animal carcasses
- D.Wastes of flowers
Show answer
Ordinary plastics are non-biodegradable, so bacteria and fungi cannot break them down in any useful length of time. Most plastics, such as polyethylene, polypropylene and PVC, are long synthetic polymers made from petroleum.
Read the full explanation →According to the Environmental Protection Agency (EPA), which one of the following is the largest source of sulphur dioxide emissions?
- A.Locomotives using fossil fuels
- B.Ships using fossil fuels
- C.Extraction of metals from ores
- D.Power plants using fossil fuels
Show answer
The EPA names the burning of fossil fuels by power plants and other industrial facilities as the largest source of sulphur dioxide.
Read the full explanation →Free swimming macroscopic animals in an aquatic environment are referred to as
- A.Plankton
- B.Periphyton
- C.Benthos
- D.Nekton
Show answer
Nekton are animals large enough to be seen with the naked eye that swim actively and can move against water currents.
Read the full explanation →Artificial way of causing rainfall to reduce air pollution makes use of
- A.silver iodide and potassium iodide
- B.silver nitrate and potassium iodide
- C.silver iodide and potassium nitrate
- D.silver nitrate and potassium chloride
Show answer
These salts are the usual seeding agents in cloud seeding, the artificial way to make rain. Cloud seeding sprays tiny particles into clouds that already hold moisture, from aircraft, rockets or ground generators.
Read the full explanation →