Class 10 Science - Chapter Control and Coordination NCERT Solutions | How does phototropism occur in plants?

Draw the structure of a neuron and explain its function.

Which signals will get disrupted in case of a spinal cord injury?

How does chemical coordination take place in animals?

Compare and contrast nervous and hormonal mechanisms for control and coordination in animals.

Why is the use of iodised salt advisable?

The brain is responsible for

(a) thinking.
(b) regulating the heart beat.
(c) balancing the body.
(d) all of the above.

How do we detect the smell of an agarbatti (incense stick)?

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

Which part of the brain maintains posture and equilibrium of the body?

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

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 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 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 are the differences between aerobic and anaerobic respiration? Name some organisms that use the anaerobic mode of respiration.

You are given a hammer, a battery, a bulb, wires and a switch.

(a) How could you use them to distinguish between samples of metals and non-metals?
(b) Assess the usefulness of these tests in distinguishing between metals and non-metals.

Can any source of energy be pollution-free? Why or why not?

Identify the substances that are oxidised and the substance that are reduced in the following reactions.

    (i)    4Na(s)   +   O₂(g)    →    2Na₂O(s)
    (ii)   CuO(s)   +   H₂(g)    →    Cu(s)   +   H₂O(l)

An element reacts with oxygen to give a compound with a high melting point. This compound is also soluble in water. The element is likely to be

(a) calcium
(b) carbon
(c) silicon
(d) iron.

A hot plate of an electric oven connected to a 220 V line has two resistance coils A and B, each of 24 Ω resistance, which may be used separately, in series, or in parallel. What are the currents in the three cases?

Why do acids not show acidic behaviour in the absence of water?

What processes would you consider essential for maintaining life?

What do you mean by a precipitation reaction? Explain by giving examples.

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