Class 10 Science - Chapter How do Organism Reproduce? NCERT Solutions | Why is variation beneficial to the speci

Draw a labelled diagram of the longitudinal section of a flower.

What are the functions performed by the testis in human beings?

Why does menstruation occur?

How will an organism be benefited if it reproduces through spores?

Can you think of reasons why more complex organisms cannot give rise to new individuals through regeneration?

Asexual reproduction takes place through budding in

(a) amoeba.
(b) yeast.
(c) plasmodium.
(d) leishmania.

How does the embryo get nourishment inside the mother’s body?

What are the advantages of sexual reproduction over asexual reproduction?

What is the importance of DNA copying in reproduction?

How does reproduction help in providing stability to populations of species?

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 difference between a reflex action and walking?

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?

Will geographical isolation be a major factor in the speciation of an organism that reproduces asexually? Why or why not?

Outline a project which aims to find the dominant coat colour in dogs.

(a)  What property do all elements in the same column of the Periodic Table as boron have in common?
(b)  What property do all elements in the same column of the Periodic Table as fluorine have in common?

Write the balanced chemical equations for the following reactions.

(a) Calcium hydroxide + Carbon dioxide → Calcium carbonate + Water
(b) Zinc + Silver nitrate → Zinc nitrate + Silver
(c) Aluminium + Copper chloride → Aluminium chloride + Copper
(d) Barium chloride + Potassium sulphate → Barium sulphate + Potassium chloride

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

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

Give any two ways in which non-biodegradable substances would affect the environment.

Let the resistance of an electrical component remains constant while the potential difference across the two ends of the component decreases to half of its former value. What change will occur in the current through it?

Name two energy sources that you would consider to be renewable. Give reasons for your choices.

How is food transported in plants?