What is the role of decomposers in the ecosystem?
Decomposition is the process of breaking down the substances into the smaller particles or the parts. Decomposition of the decay organic matter like plants, wastage of animals etc. , also known as putrefaction. In the process of decomposition mainly two decomposers are responsible, i.e, bacteria and the fungi. These two organisms breaks the dead organic matter into smaller organic molecules (utilized as nutrients by themselves) or into inorganic compounds which are released into the environment.
Decomposition involves some enzymes for the degradation of organic matter. Mainly 3 steps are involved in this process fragmentation (breakdown of the organic matter into smaller fragments), leaching (fragmented detritus particles like sugar and several nutrients get dissolved in water percolating through the soil and removed due to the leaching process) and the catabolism (release the extracellular enzymes to decompose decay particles into the simpler compounds which are carried out by the decomposers like bacteria and fungi) process occurs.
The decomposition process plays vital role in any ecosystem because it involves the release of the nutrients from the dead matter. If there is no decomposers, all the nutrients would remain locked in the dead remains of plants and the animals, so these will not be available for the indefinite recreation of the living matter.
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
How can you help in reducing the problem of waste disposal? Give any two methods.
What is ozone and how does it affect any ecosystem?
What are trophic levels? Give an example of a food chain and state the different trophic levels in it.
What will happen if we kill all the organisms in one trophic level?
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?
Five solutions A,B,C,D and E when tested with universal indicator showed pH as 4,1,11,7 and 9, respectively. Which solution is
(a) neutral?
(b) strongly alkaline?
(c) strongly acidic?
(d) weakly acidic?
(e) weakly alkaline?
Arrange the pH in increasing order of hydrogen-ion concentration.
An electric iron of resistance 20 Ω takes a current of 5 A. Calculate the heat developed in 30 s.
Light enters from air to glass having refractive index 1.50. What is the speed of light in the glass? The speed of light in vacuum is 3 × 108 m s–1.
The gap between two neurons is called a
(a) dendrite.
(b) synapse.
(c) axon.
(d) impulse.
What changes can you make in your habits to become more environment-friendly?
What is an homologous series? Explain with an example.
(a) Lithium, sodium, potassium are all metals that react with water to liberate hydrogen gas. Is there any similarity in the atoms of these elements?
(b) Helium is an unreactive gas and neon is a gas of extremely low reactivity. What, if anything, do their atoms have in common?
Describe the structure and functioning of nephrons.
Give two important uses of washing soda and baking soda.
A solution reacts with crushed egg-shells to give a gas that turns lime-water milky. The solution contains
(a) NaCl (b) HCl (c) LiCl (d) KCl