Name the organisms whose uncontrolled activities are damaging the environment.
Answer
Human beings are the only organisms which change the natural environment to fulfill their needs. The uncontrolled activities of human beings are damaging the balanced and healthy environment.
Explain why, some materials are biodegradable but some are non-biodegradable.
Answer
It is due to the property of decomposer organisms of being specific in their action that some waste materials are biodegradable and other are non- biodegradable.
The number of malaria patients in a village increased tremendously when large number of frogs were exported from the village. What could be the cause for it?
Answer
Frogs eat up mosquitoes. In the absence of frogs, the number of mosquitoes increase too much and spread malaria.
Name the organisms belonging to the second and the fourth trophic levels in the food chain comprising the following:
Frogs, Plants, Snakes, Hawk, Insects.
Answer
Second trophic level: Insects Fourth trophic level: Snakes.
If a harmful chemical enters a food chain comprising cat, mice and plants, which one of these organisms is likely to have the maximum concentration of the harmful chemical in its body?
What is meant by non-biodegradable waste materials? Give two examples of nonbiodegradable wastes.
Answer
The waste materials which cannot be broken down into non-poisonous or harmless substances in nature are called non-biodegradable waste materials. Example – D.D.T and Plastics.
Plants are called producers because green plants prepare their own food from simple inorganic substances like carbon dioxide and water by using sunlight energy in the presence of chlorophyll.
If 5 joules of energy is available at producer level (plants), then how much energy will be transferred to the lion in the following food chain? If 5 joules of energy is available at producer level (plants), then how much energy will be transferred to the lion in the following food chain? Plants → Goat → Lion