How do organisms, whether reproduced asexually or sexually maintain a constant chromosome number through several generations? Explain with the help of suitable example.
CBSE DELHI - SET 1 2016
Download our app for free and get startedPlay store
In both sexual and asexual reproduction, there is great importance of maintaining a constant number of chromosomes. But the process mechanism is dissimilar in both the type of reproductions.
  1. In case of asexual reproduction, the entire set of chromosomes is replicated and transferred to the next generation. DNA copying is accompanied by the creation of an additional cellular material, after which the DNA copies separate, each with its own cellular apparatus. Effectively, a cell divides to give rise to two cells. Thus, chromosome number remains unchanged.
For example: Replica of Amoeba by binary fission.
  1. In case of sexual reproduction, the chromosome number is halved to form gametes. Then these gametes combine to restore the original chromosome number.
For example: In the case of human beings they have 46 chromosomes present in a cell, during reproduction gametes are generated which include half the number i.e. 23. Now, when female gamete containing 23 chromosomes is combined with male gamete with 23 chromosomes, the number is restored to original 46 (23 + 23).
art

Download our app
and get started for free

Experience the future of education. Simply download our apps or reach out to us for more information. Let's shape the future of learning together!No signup needed.*

Similar Questions

  • 1
    What are the three types of methods used for birth control (or regulating child birth)? Give one example of each type.
    View Solution
  • 2
    List and explain in brief three methods of contraception.
    View Solution
  • 3
    What happens when:
    1. Accidently, Planaria gets cut into many pieces?
    2. Bryophyllum leaf falls on the wet soil?
    3. On maturation sporangia of Rhizopus bursts?
    View Solution
  • 4
    Define the term pollination. Differentiate between self pollination and cross pollination. What is the significance of pollination?
    View Solution
  • 5
    In the context of reproduction of species state the main difference between fission and fragmentation. Also give one example of each.
    View Solution
  • 6
    State the changes that take place in the uterus when:
    1. Implantation of embryo has occurred.
    2. Female gamete/ egg is not fertilised.
    View Solution
  • 7
    Explain the term "Regeneration" as used in relation to reproduction of organisms. Describe briefly how regeneration is carried out in multicellular organisms like Hydra.
    View Solution
  • 8
    1. Mention the role of the following organs of human male reproductive system:
    1. Testis.
    2. Scrotum.
    3. Vas deferens.
    4. Prostate glands.
    1. What are the two roles of testosterone?
    View Solution
  • 9
    List any four methods of contraception used by humans. How does their use have direct effect on the health and prosperity of a family?
    View Solution
  • 10
    Write one difference between asexual and sexual mode of reproduction. Which species is likely to have better chances of survival – the one reproducing asexually or the one reproducing sexually? Justify your answer.
    View Solution