Important Questions for Class 10 Science Chapter 8 – How do Organisms Reproduce?

Important Questions for Class 10 Science Chapter 8 – How do Organisms Reproduce?

Below are some important questions for class 10 science chapter 8 – How do Organisms Reproduce? students must study thoroughly.Reproduction is a biological process where an organism reproduces biologically similar offspring. It is an essential life process that aids in the multiplication of an organism and the expansion of its population. Reproduction in organisms usually occurs in two different ways – Asexual reproduction and Sexual reproduction. Bacteria, amoeba, hydra, and other microorganisms reproduce asexually, where the offspring is produced by a single parent. Sexual reproduction is the reproductive process of creating new organisms by combining the genetic information of two parents of different sexes.

Some of the important questions topics for class 10 science chapter 8 – How do Organisms Reproduce? are:

  • Different unicellular and multicellular organisms’ reproduction
  • Different reproductive structures
  • Modes of reproduction

Below are some of the important questions for class 10 science chapter 8 – How do Organisms Reproduce? from an examination point of view.

Class 10 Science Important Questions Chapter 8 – How do Organisms Reproduce?

Q1. Reproduction is one of the most important characteristic ‘of living beings. Give three reasons in support of the statement.


Reproduction is one of the most important characteristics of living beings because :

  • it is essential for existence and continuity of a species.
  • it helps to pass genetic information to next generation.
  • it brings variations in next generation which is the basis for evolution.

Q2. Define reproduction. How does it helps in providing stability to the population of species? 


The production of new organisms by the existing organisms of the same species is known as reproduction. It is linked to the stability of population of a species. DNA replication during reproduction ensures transfer of specific characters or body design features that is essential for an individual of a population to live and use that particular niche. Some variations present in a few individuals of population caused due to reproduction which also helps in their survival at changing niches.

Q3. What is the effect of DNA copying, which is not perfectly accurate, on the reproduction process? How does the amount of DNA remain constant through each new generation is a combination of DNA copies of two individuals?


In the process of reproduction, if DNA copying is not perfectly accurate, variation occurs. These in turn may allow few individuals of a population to survive in an altered niche and becomes the basis of evolution and over time. Such variations are useful for the survival of species.

The combination of DNA copies of two individuals, (male and female) occurs during sexual reproduction. Reduction division (meiosis) during gamete formation halves the chromosome number in both male and female gametes. Since these two gametes fuse during fertilisation, the original number of chromosomes (as in the parent) is restored in the offspring. By this way the amount of DNA remains constant in each new generation.

Q4. What are sexually transmitted diseases? Write two examples each of sexually transmitted diseases caused by (i) virus, (ii) bacteria. Explain how the transmission of such diseases is prevented?


Diseases which are transmitted from an infected person to a healthy person due to sexual contract are called Sexually Transmitted Diseases (STD).

Sexually transmitted diseases caused by

(i) Virus:

AIDS (Acquired Immuno Deficiency Syndrome)

Genital warts

(ii) Bacteria:



Transmission of such diseases can be prevented in the following ways:

  • Screening tests for blood donors
  • Mutually faithful monogamous relationships
  • Educating people in high-risk groups
  • Using condoms etc.

Q5. Name the blueprint responsible for making all basic body designs.


DNA (Deoxyribonucleic acid) is considered as the blueprint for making all basic design of an organism.

The DNA is present in the nucleus of a cell in the form of a condensed structure called chromosome.

Q6. What is the significance of body design in determining the habitat of an organism?


Body design/ morphology of an organism defines the way how much he is fitted or suitable for a specific habitat. E.g.- a bacteria doesn’t need big houses or area to survive and also it’s nutritional requirements are very less but humans, on the other hand, need much larger space and have complex nutrition system. A fish can survive under water because of gills but a bird or human cannot.

Q7. Why do spores remain viable during unfavorable conditions?


Sporulation occurs under an unfavorable environment like high temperature, ph., etc. Where a normal cell cannot survive. So bacteria and fungi can convert their cells into a spore. These spores have all the nutrition required for growth but have very less water content which makes it hard and unreactive to the harsh environment. Also, some spores have an extra protective covering of lipids, polysaccharides or some proteinaceous substance that makes it withstand the harsh environment.

Q8. List two advantages of growing grapes or banana plants through vegetative propagation.  


Two advantages of growing grapes or banana plant through vegetative propagation:

  • The fruit trees grown through vegetative propagation bear fruits much earlier.
  • Banana and grapes produce either very few seeds or do not produce viable seeds. Therefore their plants are grown by vegetative propagation.

Q9. List four advantages of vegetative propagation.


Advantages of vegetative propagation:

  • Plants grown by vegetative propagation grow much faster than those grown from seeds.
  • A large number of plants can be produced by the method of vegetative propagation.
  • The plants grown by vegetative propagation usually need less attention in their early years than the plants grown from seeds.
  • Seedless plants can also be grown from this method.

Q10. What does HIV stand for? Is AIDS an infectious disease? List any four modes of spreading AIDS. 


HIV. Human Immuno Deficiency Virus

This virus causes AIDS which is an infectious disease.

Modes of spreading AIDS:

  • The AIDS disease usually spreads through unprotected sexual contact with an infected person carrying AIDS virus.
  • The AIDS disease also spreads through the transfusion of blood contaminated with AIDS virus.
  • The AIDS disease also spreads through the use of infected needles for injections.
  • An AIDS infected mother can transmit the virus to her child during pregnancy or during birth.