Science In Everyday Life Solutions for Class 8 Science Chapter 9 Reproduction are provided here with simple step-by-step explanations. These solutions for Reproduction are extremely popular among class 8 students for Science Reproduction Solutions come handy for quickly completing your homework and preparing for exams. All questions and answers from the Science In Everyday Life Book of class 8 Science Chapter 9 are provided here for you for free. You will also love the ad-free experience on Meritnation’s Science In Everyday Life Solutions. All Science In Everyday Life Solutions for class 8 Science are prepared by experts and are 100% accurate.

Page No 135:

Question 1:

What do you understand by reproduction? What are the two kinds of reproduction?

Answer:

The process by which living organisms produce offspring or young ones of their own kind is called reproduction. The two types of reproduction are asexual reproduction and sexual reproduction.

Page No 135:

Question 2:

Differentiate between asexual and sexual reproduction.

Answer:

Asexual reproduction Sexual reprodcution
A new individual is formed from the cell of a single parent. New organism is formed from the reproductive cells of two parents.
E.g. Binary fission as in amoeba and budding as in hydra. E.g. Most plant, mammals and human beings.

Page No 135:

Question 3:

Name the male and female gametes.

Answer:

The male gamete is sperm and the female gamete is the ovum.

Page No 135:

Question 1:

Write one word for the following.

1. Reproductive cells ....................
2. Male gamete ....................
3. Female gamete ....................
4. Process that results in fusion of two gametes ....................
5. Thread-like structures inside the nucleus that carry information in the form of genes ....................
6. Baby during the first eight weeks after fertilization ....................
7. A series of drastic changes that transform a larva into an adult ....................
8. Technique used for killing of girl foetus ....................

Answer:

  1. Gametes
  2. Sperm
  3. Ovum
  4. Fertilization
  5. Chromosomes
  6. Embryo
  7. Metamorphosis
  8. Abortion

Page No 135:

Question 2:

Write two examples for each of the following.

1. Organisms that reproduce asexually .................... ....................
2. Types of fertilization .................... ....................
3. Hormones that control metamorphosis .................... ....................

Answer:

  1. Amoeba, Hydra
  2. Internal, external
  3. Thyroxine, ecdysone

Page No 135:

Question 1:

Sperm and ovum fuse to form a
(a) foetus
(b) embryo
(c) zygote
(d) sperm

Answer:

(c) Zygote
Sperm and ovum fuse during fertilization and form a zygote.

Page No 135:

Question 2:

.................... produce/s male sex hormone.
(a) Testes
(b) Vas deferens
(c) Penis
(d) Ovary

Answer:

(a) Testes
The testes produce male sex hormones.

Page No 135:

Question 3:

Ovum is fertilized in the
(a) ovary
(b) oviduct
(c) cervix
(d) vagina

Answer:

(b) Oviduct
The sperm fuses with the ovum in the oviduct or fallopian tube.

Page No 135:

Question 4:

After fertilization, the ovum implants itself in the
(a) ovary
(b) uterus wall
(c) vagina
(d) vas deferens

Answer:

(b) Uterus wall
The fertilized ovum is implanted into the uterus wall.

Page No 135:

Question 5:

The two types of sex chromosomes are
(a) X and Y
(b) Y and Z
(c) A and B
(d) A and X

Answer:

(a) X and Y
X and Y are the two types of sex chromosomes.

Page No 135:

Question 1:

Match the following.

Column A Column B
Sperm Cat
Internal fertilization Frog
External fertilization Female
Cervix Male

Answer:

Column A Column B
Sperm Male
Internal fertilization Cat
External fertilization Frog
Cervix Female



Page No 136:

Question 4:

List the male and female reproductive organs of the human body.

Answer:

  1. The reproductive organs in males are testes, sperm duct, penis and urethra.
  2. The reproductive organs in females are uterus, ovaries, oviducts and vagina.

Page No 136:

Question 5:

What is fertilization? Differentiate between internal and external fertilization.

Answer:

Fertilization is the fusion of male and female gametes to produce a new organism. 
 

Internal fertilization External fertilization
Fusion of male and female gametes occur inside the female’s body. Fusion of male and female gametes occur outside.
E.g. Mammals like cats, dogs and humans. E.g. Frog, starfish and fish.

Page No 136:

Question 6:

How does the baby grow inside the womb?

Answer:

A baby grows as an embryo in the womb till eight weeks after fertilization. Then, the foetus grows in the womb till around 40 weeks until it fully develops after which the mother gives birth to the baby. 

Page No 136:

Question 7:

Differentiate between viviparous and oviparous animals.

Answer:

Viviparous animals Oviparous animals
They give birth to living offspring. They lay eggs that hatch into offspring.
E.g. Mammals like horses, cats and humans E.g. Birds, frogs, egg laying snakes

Page No 136:

Question 8:

What is metamorphosis? Name the three stages in the life cycle of a frog.

Answer:

Metamorphosis is the maturation of larva into an adult through a series of drastic physical and physiological changes.

The stages in a life cycle of a frog are egg, larva or tadpole and adult.

Page No 136:

Question 9:

Name the main stages in the life cycle of a butterfly.

Answer:

The main stages in the life cycle of a butterfly are
(i) egg,
(ii) larva or caterpillar,
(iii) pupa and
(iv) adult.

Page No 136:

Question 10:

List some problems associated with adolescent pregnancy.

Answer:

Adolescent pregnancy is dangerous to life of the mother and the baby as the mother is not mentally and physically prepared for this role. Along with health problems, it may also cause educational restrictions and overall social growth.

Page No 136:

Question 11:

How is the government of India trying to control female infanticide?

Answer:

To stop the practice of female infanticide, the Indian government has made it illegal to determine the sex of the foetus by any technique.

Page No 136:

Question 1:

With the help of diagrams, explain how an Amoeba and a Hydra multiply.

Answer:

Amoeba and Hydra undergo asexual reproduction, which is a simplest form of reproduction. In this mode of reproduction, cell from only one parent is used.

  • Amoeba multiplies by binary fission. In this form of asexual reproduction, the nucleus divides into two which is then followed by the division of the cell body into two parts with each part having a nucleus. Thus, two separate daughter amoebae are formed.

 
  • Hydra multiplies by budding, in which a bulge called bud is formed. The bud grows and forms a baby hydra, which then separates from the parent hydra. 

Page No 136:

Question 2:

Describe the different stages of reproduction in human beings.

Answer:

The different stages of human reproduction are:

  • Fertilization- during which the male gamete or sperm fuses with the female gamete or ovum to form a zygote, inside the female’s body.
  • Zygote implants itself into wall of uterus and divides into large number of cells
  • Embryo – Zygote develops to form an embryo.
  • This development continues till the embryo grows and a baby is born. 

Page No 136:

Question 3:

Describe the structures and functions of the different male and female reproductive organs.

Answer:

The male reproductive organs are:

  • Testis – Males have two testes, which is an endocrine gland made up of coiled tubes that produce sperms. They produce male sex hormone, testosterone.
  • Sperm duct – A narrow tube that transports sperms produced in testes and secrete fluids that mix with sperms to form semen.
  • Penis – It transfers sperms filled semen into a female’s body.
  • Urethra – A tube inside penis that allows urine and semen to flow out.
The female reproductive organs are:
  • Ovary – It is an almond shaped endocrine gland and females have two ovaries. It secretes female sex hormone oestrogen.
  • Uterus – It is the womb where a zygote matures and an embryo develops grows till birth.
  • Vagina – It receives the penis during sexual intercourse.  
 

Page No 136:

Question 4:

Explain in detail the main stages of fertilization in human beings.

Answer:

The main stages of fertilization in human beings are

  • During ovulation a matured ovum is released from the ovaries, once in a month.
  • This ovum moves into the oviduct.
  • When sexual intercourse occurs and sperms are transferred into the vagina through the penis, the sperms travel through an opening called cervix and reach the oviduct.
  • Fertilization takes place when a single sperm fuses with the ovum in the oviduct. The fertilized ovum or the zygote, travels down the oviduct and reaches uterus.
  • The zygote gets implanted into the uterus wall and develops to form a human embryo.

Page No 136:

Question 5:

Explain with an example, how sex of a baby can be determined with the help of chromosomes.

Answer:

Chromosomes carry information in the form of genes and are responsible for determining the sex. Females have XX pair of sex chromosomes, while males have XY pair. Gametes have only one member of this pair. Ovum has the X chromosome, while sperm cell has either X or Y chromosomes. When the gametes fuses, these single members (X and X or X and Y) also unite to form a new pair of chromosomes, which determines the sex of the baby. E.g., The X chromosome from the ovum unites with the X chromosome of the sperm cell; the resulting zygote has XX pair of chromosome. This is determined as a female.



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