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NCERT Solution for Class 8 Science Chapter 6 Reproduction in Animals

Last Updated : 29 May, 2023
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NCERT Solutions for class 8 Chapter- 6 Reproduction in Animals: The chapter on Reproduction in animals is important for students approaching the exams. This article introduces NCERT solutions designed to help students explain the concepts of further learning and how to write to get good grades on exams. The solutions are presented in very simple language for ease of understanding.

Solutions of NCERT CBSE Science Chapter 6 Reproduction in Animals of Class 8 explains the role of reproduction in animals and how it is important for humans. Revise the basic concepts of Reproduction in animals for quick revision and class notes.

Q1: Explain the Importance of Reproduction in Organisms.

Answer:

Reproduction is important for the continuation of species and it keeps the species from becoming extinct. It also plays an important role in the evolution and increases in the number of species in an ecosystem.

Q2: Describe the Process of Fertilisation in Human beings.

Answer:

Fertilisation is the process in which the male gamete fuses with the female gamete. In human beings, the male gamete is sperm and the female gamete is the ovum both are fuses and form zygotes.

Q3: Choose the most appropriate answer.

  1. (a) Internal fertilization occurs 
    1. (i) in the female body. 
    2. ii) outside the female body. 
    3. (iii) in the male body. 
    4. (iv) outside male body.
  2. (b) A tadpole develops into an adult frog by the process of 
    1. (i) fertilization 
    2. (ii) metamorphosis 
    3. (iii) embedding 
    4. (iv) budding
  3. (c) The number of nuclei present in a zygote is 
    1. (i) none 
    2. (ii) one 
    3. (iii) two 
    4. (iv) four

Answer:

  1. (a) Internal fertilization is the process in which male gamete sperm enters the female body and fuses with the female gamete. So, option (ⅰ) is correct.
  2. (b) Metamorphosis is a process in which an immature form is transformed into an adult form in two or more different stages. 
    Example: Tadpole develops into an adult frog. So, (ⅱ) is the correct option.
  3. (c) Zygote is uni-nucleate. Hence, option (ⅱ) is correct.

Q4: Indicate whether the following statements are True (T) or False (F).

  • (a) Oviparous animals give birth to young ones.
  • (b) Each sperm is a single cell.
  • (c) External fertilization takes place in frogs.
  • (d) A new human individual develops from a cell called a gamete.
  • (e) Egg laid after fertilization is made up of a single cell.
  • (f) Amoeba reproduces by budding.
  • (g) Fertilisation is necessary even in asexual reproduction.
  • (h) Binary fission is a method of asexual reproduction.
  • (i) A zygote is formed as a result of fertilization.
  • (j) An embryo is made up of a single cell.

Answer:

  • (a) Oviparous animals lay eggs while viviparous animals give birth to young ones. So, the given option is false.
  • (b) Each sperm is a haploid cell. So, the given option is true.
  • (c) During external fertilization, the fusion between male and female gamete occurs outside the female body. Example: Aquatic animals like frogs. So, the given statement is True.
  • (d) Gamete is a haploid cell that fuses with another cell and forms a diploid zygote. so, the given statement is False.
  • (e) During fertilization male gamete fuses with the female gamete and forms a single cell i.e. called a zygote. So the given statement is True.
  • (f) In amoeba reproduction takes place through binary fission. So, the given statement is false.
  • (g)In asexual reproduction the fusion of male and female gamete does not occur while in fertilization fusion of male and female gamete occurs. So, the given statement is false.
  • (h) Binary fission is a method of asexual reproduction. So, the given statement is true.
  • (i) During fertilization male gamete fuses with the female gamete and forms a single cell i.e. called a zygote. So, the given statement is True.
  • (j) The first step of embryo formation is the formation of a zygote which is single-celled. So, the given statement is true.

Q5: Give two differences between a Zygote and a Fetus.

Answer:

Zygote

Fetus

Zygote is formed after the fertilization process.

Foetus is the stage of the embryo in which body parts could be recognizable.

Organs are not well developed.

Several organs are well-developed.

Q6: Define Asexual Reproduction. Describe Two Methods of Asexual Reproduction in Animals.

Answer:

In the asexual mode of reproduction, only a single parent is involved to reproduce offspring. In this mode of reproduction, the offspring is the exact copy of their parents. Different methods that occur in asexual reproduction are Binary fission, Budding, etc.

Binary Fission

 

  • Binary fission: In this method a single cell divides into two daughter cells. Example: Amoeba.
  • Budding: In this method, small outgrowth develops on the parent body i.e. called bud and this bud enlarges then detaches from the parent body and develops into a new individual. Example; Hydra and bacteria.
Budding

 

Q7: In which Female Reproductive Organ does the embryo get embedded?

Answer:

The embryo gets embedded in the uterus because the uterine wall is present. In the uterus, the embryo continues to grow into a foetus during the gestation period.

Q8: What is Metamorphosis? Give examples.

Answer:

Metamorphosis is a process in which an immature form is transformed into an adult form in two or more different stages. 
Example: Frogs, Butterflies etc.

Q9: Differentiate between Internal Fertilisation and External Fertilisation.

Answer:

Internal Fertilisation.

External Fertilisation

It occurs in the female body.

It occurs outside the female body.

E.g. Reptiles, birds, mammals etc.

E.g. Amphibians, Fish etc.

Q10: Complete the crossword puzzle using the hints given below.

Puzzle Q-10

 

Across

  • 1. The process of the fusion of the gametes.
  • 6. The type of fertilization in the hen.
  • 7. The term used for bulges observed on the sides of the body of a hydra.
  • 8. Eggs are produced here.

Down

  • 2. Sperms are produced in these male reproductive organs.
  • 3. Another term for in vitro fertilization.
  • 4. These animals lay eggs.
  • 5. A type of fission in amoeba.

Answer:

Puzzle Q-10 Solution



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