Class 10 Science - Chapter How do Organism Reproduce? NCERT Solutions | Why does menstruation occur?

Why is variation beneficial to the species but not necessarily for the individual?

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

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

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

Asexual reproduction takes place through budding in

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

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

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

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

What is the importance of DNA copying in reproduction?

What are the advantages of sexual reproduction over asexual reproduction?

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?

(i) Write the electron-dot structures for sodium, oxygen and magnesium.

(ii) Show the formation of Na₂O and MgO by the transfer of electrons.

(iii) What are the ions present in these compounds?

What would you observe when zinc is added to a solution of iron(II) sulphate? Write the chemical reaction that takes place.

A ray of light travelling in air enters obliquely into water. Does the light ray bend towards the normal or away from the normal? Why?

What is meant by power of accommodation of the eye?

How many 176 Ω resistors (in parallel) are required to carry 5 A on a 220 V line?

Why is the use of iodised salt advisable?

Which of the following pairs will give displacement reactions?

(a) NaCl solution and copper metal
(b) MgCl₂ solution and aluminium metal
(c) FeSO₄ solution and silver metal
(d) AgNO₃ solution and copper metal.

You must have seen tarnished copper vessels being cleaned with lemon or tamarind juice. Explain why these sour substances are effective in cleaning the vessels.

How would these advantages differ from the advantages of using a long-term perspective in managing our resources?

What are fossils? What do they tell us about the process of evolution?