Q1:
Question for Assertion & Reason Type Questions: Our Environment
Try yourself: Directions: In the following questions, a statement of assertion (A) is followed by a statement of reason (R). Mark the correct choice as:Assertion (A): The concentration of harmful chemicals is more in human beings.
Reason (R): Man is at the apex of the food chain.
Explanation
Harmful chemicals accumulate progressively at each trophic level. Since man is at the apex of all the food chains, the concentration of harmful chemicals may be more in human beings. The phenomenon involved is known as biomagnification.
Report a problem
Q2:
Question for Assertion & Reason Type Questions: Our Environment
Try yourself: Directions: In the following questions, a statement of assertion (A) is followed by a statement of reason (R). Mark the correct choice as:Assertion (A): First trophic level in a food chain is always a green plant.
Reason (R): Green plants are called producers.
Explanation
Green plants are producers. The first trophic level in a food chain is the producers i.e. those organisms which produce food by photosynthesis.
Report a problem
Q3:
Question for Assertion & Reason Type Questions: Our Environment
Try yourself: Directions: In the following questions, a statement of assertion (A) is followed by a statement of reason (R). Mark the correct choice as:Assertion (A): Herbivores are called first order consumers.
Reason (R): Tiger is a top carnivore.
Explanation
Herbivores obtain their food from plants. Hence, they are known as first order carnivores. The carnivores like tigers that cannot be preyed upon further, lie at the top of the food chain and hence termed as top carnivores.
Report a problem
Q4:
Question for Assertion & Reason Type Questions: Our Environment
Try yourself: Directions: In the following questions, a statement of assertion (A) is followed by a statement of reason (R). Mark the correct choice as:Assertion: Food chain is responsible for the entry of harmful chemicals in our bodies.
Reason: The length and complexity of food chains vary greatly.
Explanation
The length of the food chain varies with different food chains. It depends on the amount of transferable energy that is available at the producers and on population size of the consumers.
Report a problem
Q5:
Question for Assertion & Reason Type Questions: Our Environment
Try yourself: Directions: In the following questions, a statement of assertion (A) is followed by a statement of reason (R). Mark the correct choice as:Assertion: Greater number of individuals are present in lower trophic levels.
Reason: The flow of energy is unidirectional.
Explanation
Producer is the first trophic level of the terrestrial food chains. Generally organisms at the lowest trophic level are always greater in number. As we move to the higher trophic levels, the number and the complexity of organisms increase. This helps to maintain the balance in the ecosystem. If there would have less producers compared to primary consumers; they would have starved and the further food chains could have been disturbed.
Also the amount of energy transferred from one tropic level to the other is less (10%), hence is it important that a larger population exist for a lower trophic level than that found above it.
Report a problem
Q6:
Question for Assertion & Reason Type Questions: Our Environment
Try yourself: Directions: In the following questions, a statement of assertion (A) is followed by a statement of reason (R). Mark the correct choice as:Assertion (A): Flow of energy in a food chain is unidirectional.
Reason (R): Energy captured by autotrophs does not revert back to the solar input and it passes to the herbivores.
Explanation
The flow of energy through different steps in the food chain is unidirectional. This means that energy captured by autotrophs does not revert back to the solar input and it passes to the herbivores.
Report a problem
Q7:
Question for Assertion & Reason Type Questions: Our Environment
Try yourself: Directions: In the following questions, a statement of assertion (A) is followed by a statement of reason (R). Mark the correct choice as:Assertion (A): Decomposers keep the environment clean.
Reason (R): They recycle matter by breaking down the organic remains and waste products of plants and animals.
Explanation
Decomposers keep the environment clean by decomposing or consuming the dead remains of other organisms.
Report a problem
Q8:
Question for Assertion & Reason Type Questions: Our Environment
Try yourself: Directions: In the following questions, a statement of assertion (A) is followed by a statement of reason (R). Mark the correct choice as:Assertion (A): Polythene bags and plastic containers are non-biodegradable substances.
Reason (R): They can be broken down by microorganisms in natural simple harmless substances.
Explanation
Substances like polythene bags and plastics are non-biodegradable because they cannot be broken down by micro-organisms into simpler harmless substances in nature. Substances that can be broken down by microorganisms in natural simple harmless substances are biodegradable substances.
Report a problem
Q9:
Question for Assertion & Reason Type Questions: Our Environment
Try yourself: Directions: In the following questions, a statement of assertion (A) is followed by a statement of reason (R). Mark the correct choice as:Assertion (A): Ozone is both beneficial and damaging.
Reason (R): Stop the release of chlorofluorocarbons to protect the ozone.
Explanation
Ozone is damaging as it is a deadly poison. It is beneficial as it shields the surface of the earth from UV radiations of the Sun. We should stop the release of Chlorofluorocarbons (CFCs) to protect the ozone.
Report a problem
Q10:
Question for Assertion & Reason Type Questions: Our Environment
Try yourself: Directions: In the following questions, a statement of assertion (A) is followed by a statement of reason (R). Mark the correct choice as:Assertion (A): CFCs deplete the ozone layer.
Reason (R): CFCs are used as refrigerants and in fire extinguishers.
Explanation
Ozone layer is getting depleted at the higher levels of the atmosphere due to effect of chlorofluorocarbons (CFCs) which are used as refrigerants and in fire extinguishers.
Report a problem