Indicate the flow of energy in an ecosystem. Why is it unidirectional ? Justify.
The flow of energy generally is as follows:
Sun ———>Producers ———> Herbivores ———> Carnivores
Since, flow is progressively from one trophic level to another and does not revert back, it is said to be unidirectional, i.e. from sun to plants, plants to animals,
animals to other animals and organic remains to decomposers. Thus, the available energy decreases in the higher trophic levels making impossible for energy flow in reverse direction.
Name the phenomenon in which non-biodegradable chemicals get accumulated progressively at each trophic level of a food chain.
(a) What is meant by biodegradable waste materials ? Give two examples of biodegradable wastes.
(b) Which of the following materials are non-biodegradable ?
Aluminium wire, Tea leaves, Synthetic fibre, Wool
Which of the following belong to the first trophic level of a food chain? Grass, Grasshopper, Plants, Rat, Tiger [Foreign]
Select two non-biodegradable substances from the following waste generated in a kitchen: spoilt food, paper bags, milk bags, vegetable peels, tin cans, used tea leaves. [Delhi]
What is the functional unit of the environment comprising of the living and non-living components called ?
Which one of the following is not a terrestial ecosystem ?
Forest, Grassland, Aquarium, Desert
Which one term in the following includes the others ?
air, flora, fauna, environment, water, sunlight, soil
Explain how, harmful ultraviolet radiations of sunlight are prevented from reaching the earth’s surface.
Name the wastes which are generated in your house daily. What measures would you take for their disposal?
Why are bacteria and fungi called decomposers? List any two advantages of decomposers to the environment. [Delhi]
State whether the following statements are true or false :State whether the following statements are true or false :
(a) In biology, human beings are called producers.
(b) Secondary consumers and tertiary consumers, both are carnivores.
Describe how decomposers facilitate recycling of matter in order to maintain balance in the ecosystem. [Foreign]
Why did United Nations act to control the production of chlorofluorocarbons (CFCs) used in refrigerators? [Delhi]
Which class of chemicals is linked to the decrease in the amount of ozone in the upper atmosphere of the earth? [Delhi]
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 ?
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
In a food chain, 10,000 joules of energy is available to the producer. How much energy will be available to the secondary consumer to transfer it to the tertiary consumer? [All India ]
Explain the terms ‘producer’ and ‘consumer’. Give two examples of producers and two of consumers.