Class 10 Science Life Processes: NCERT Solutions for Question 4

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

How is the amount of urine produced regulated?

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

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

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?

Where do plants get each of the raw materials required for photosynthesis?

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?

A positively-charged particle (alpha-particle) projected towards west is deflected towards north by a magnetic field. The direction of magnetic field is

   (a) towards south                 (b) towards east
   (c) downward                       (d) upward

What effect does the concentration of H⁺(aq) ions have on the nature of the solution?

The position of three elements A, B and C in the Periodic Table are shown below –

      Group 16          Group 17
            -                       -
            -                       A
            -                       -
            B                      C

(a) State whether A is a metal or non-metal.
(b) State whether C is more reactive or less reactive than A.
(c) Will C be larger or smaller in size than B?
(d) Which type of ion, cation or anion, will be formed by element A?

How do auxins promote the growth of a tendril around a support?

Why are decomposition reactions called the opposite of combination reactions? Write equations for these reactions.

An electric motor takes 5 A from a 220 V line. Determine the power of the motor and the energy consumed in 2 h.

Which of the statements about the reaction below are incorrect?

2PbO(s) + C(s) → 2Pb(s) + CO₂(g)

(a) Lead is getting reduced.
(b) Carbon dioxide is getting oxidised.
(c) Carbon is getting oxidised.
(d) Lead oxide is getting reduced.

       (i) (a) and (b)
       (ii) (a) and (c)
       (iii) (a), (b) and c
       (iv) all

Which of the following property of a proton can change while it moves freely in a magnetic field? (There may be more than one correct answer.)

  (a) mass                  (b) speed
  (c) velocity               (d) momentum

What is the role of the split ring in an electric motor?

What is the difference between displacement and double displacement reactions? Write equations for these reactions.