Will the impact of removing all the organisms in a trophic level be different for different trophic levels? Can the organisms of any trophic level be removed without causing any damage to the ecosystem?
The impact of removing all the organisms in the trophic level will be the same at each independent trophic level. When we remove or kill the organism of any trophic level it will be an damage to the ecosystem.
For example, in a pond food chain:-
Phytoplanktons ← Zooplanktons ← Small fishes ← Large fishes ← Snakes, birds
In this food chain phytoplanktons are eaten by zooplanktons and then zooplanktons get eaten by the small fishes; small fishes are eaten by the large fishes in the pond and then at the last trophic level large fishes get caught and eaten by the snake or the birds. So, we can see that all the trophic levels in the ecosystem are dependent on each other. If we remove any one trophic level population like we remove zooplanktons in the food chain then the lower trophic level, i.e, phytoplanktons population will get increase in number which will disturb the entire ecosystem.
What is biological magnification? Will the levels of this magnification be different at different levels of the ecosystem?
Give any two ways in which biodegradable substances would affect the environment.
Which of the following constitute a food-chain?
(a) Grass, wheat and mango
(b) Grass, goat and human
(c) Goat, cow and elephant
(d) Grass, fish and goat
If all the waste we generate is biodegradable, will this have no impact on the environment?
Why are some substances biodegradable and some non-biodegradable?
Which of the following groups contain only biodegradable items?
(a) Grass, flowers and leather
(b) Grass, wood and plastic
(c) Fruit-peels, cake and lime-juice
(d) Cake, wood and grass
What is ozone and how does it affect any ecosystem?
How can you help in reducing the problem of waste disposal? Give any two methods.
What are trophic levels? Give an example of a food chain and state the different trophic levels in it.
What is the role of decomposers in the ecosystem?
Did Döbereiner’s triads also exist in the columns of Newlands’ Octaves? Compare and find out.
What is a good source of energy?
Why is diffusion insufficient to meet the oxygen requirements of multi-cellular organisms like humans?
What changes can you make in your habits to become more environment-friendly?
What is the difference between a reflex action and walking?
What is the importance of DNA copying in reproduction?
If a trait A exists in 10% of a population of an asexually reproducing species and a trait B exists in 60% of the same population, which trait is likely to have arisen earlier?
Why should a magnesium ribbon be cleared before burning in air?
Define the principal focus of a concave mirror.
You have been provided with three test tubes. One of them contains distilled water and the other two contain an acidic solution and a basic solution, respectively. If you are given only red litmus paper, how will you identify the contents of each test tube?
What changes can you make in your habits to become more environment-friendly?
What are the components of the transport system in human beings? What are the functions of these components?
How do Mendel’s experiments show that traits are inherited independently?
What type of oxides are formed when non-metals combine with oxygen?
Give an example of a double displacement reaction other than the one given in activity 1.10.
What is the function of receptors in our body? Think of situations where receptors do not work properly. What problems are likely to arise?
Design an experiment to demonstrate hydrotropism.
People use a variety of methods to wash clothes. Usually after adding the soap, they ‘beat’ the clothes on a stone, or beat it with a paddle, scrub with a brush or the mixture is agitated in a washing machine. Why is agitation necessary to get clean clothes?
State Fleming’s left-hand rule.
What changes would you suggest in your home in order to be environment-friendly?