How can you help in reducing the problem of waste disposal? Give any two methods.
Waste disposal problems can be reduced. Two methods are following:-
When we buy plastic bottle of water or plastic glasses, single use plastic or any disposable items, they pollute the environment because they are non- biodegradable. So, by minimizing their use, we should promote the use of recycling items which will be beneficial for the ecosystem.
We should use jute bags instead of polythene when we go for shopping or for purchasing anything. It can help in reducing the waste disposal, and will reduce the pollution ultimately.
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?
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?
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?
Use the data in Table 12.2 to answer the following –
(a) Which among iron and mercury is a better conductor?
(b) Which material is the best conductor?
What are the advantages of nuclear energy?
The magnification produced by a plane mirror is +1. What does this mean?
What are the different ways in which glucose is oxidised to provide energy in various organisms?
What happens at the synapse between two neurons?
Compare the functioning of alveoli in the lungs and nephrons in the kidneys with respect to their structure and functioning.
How are the lungs designed in human beings to maximise the area for exchange of gases?
Fe2O3 + 2Al → Al2O3 + 2Fe
The above reaction is an example of a
(a) combination reaction.
(b) double displacement reaction.
(c) decomposition reaction.
(d) displacement reaction.
Which signals will get disrupted in case of a spinal cord injury?
Write one equation each for decomposition reactions where energy is supplied in the form of heat, light or electricity.