Class 10 Science - Chapter Life Processes NCERT Solutions | Why is it necessary to separate oxygenat

Why is diffusion insufficient to meet the oxygen requirements of multi-cellular organisms like humans?

How is the amount of urine produced regulated?

What criteria do we use to decide whether something is alive?

What are the different ways in which glucose is oxidised to provide energy in various organisms?

The breakdown of pyruvate to give carbon dioxide, water and energy takes place in

        (a) cytoplasm.               (c) chloroplast.
        (b) mitochondria.           (d) nucleus.

What are the differences between autotrophic nutrition and heterotrophic nutrition?

What are outside raw materials used for by an organism?

What would be the consequences of a deficiency of haemoglobin in our bodies?

What are the components of the transport system in highly organised plants?

What advantage over an aquatic organism does a terrestrial organism have with regard to obtaining oxygen for respiration?

Did Döbereiner’s triads also exist in the columns of Newlands’ Octaves? Compare and find out.

What is a good source of energy?

What are trophic levels? Give an example of a food chain and state the different trophic levels in it.

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?

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?

What happens when dilute hydrochloric acid is added to iron fillings? Tick the correct answer.

(a) Hydrogen gas and iron chloride are produced.
(b) Chlorine gas and iron hydroxide are produced.
(c) No reaction takes place.
(d) Iron salt and water are produced.

How does our body respond when adrenaline is secreted into the blood?

Why do we prefer a convex mirror as a rear-view mirror in vehicles?

What will happen if we kill all the organisms in one trophic level?

Food cans are coated with tin and not with zinc because

(a) zinc is costlier than tin.
(b) zinc has a higher melting point than tin.
(c) zinc is more reactive than tin.
(d) zinc is less reactive than tin.

What factors could lead to the rise of a new species?

A spherical mirror and a thin spherical lens have each a focal length of –15 cm. The mirror and the lens are likely to be

(a) both concave.
(b) both convex.
(c) the mirror is concave and the lens is convex.
(d) the mirror is convex, but the lens is concave.

What are the limitations of the energy that can be obtained from the oceans?

A solution of a substance 'X' is used for whitewashing.

   (i)  Name the substance 'X' and write its formula.
   (ii) Write the reaction of the substance 'X' named in (i) above with water.