Lakhmir Singh Manjit Kaur Class 8 Science 9th Chapter Reproduction In Amimals

Lakhmir Singh and Manjit Kaur Science solution: Reproduction In Animals Chapter 9. Here you get easy solutions of Lakhmir Singh and Manjit Kaur Science solution Chapter 9. Here we give Chapter 9 all solution of Class 8. Its help you to complete your homework.

Board – CBSE

Text Book – SCIENCE

Class – 8

Chapter – 9

VERY SHORT ANSWER TYPE QUESTIONS Answer   

(1) Reproduction.

(2) A> Sexual reproduction b> asexual reproduction.

(3) a> Dog, Cat. b> amoeba, hydra.

(4) Sexual method.

(5) a> Sexual. b> Asexual.

(6) Zygote

(7) Fertilization.

(8) No.

(9) Gamete.

(10) Ovaries, Testis.

(11) a> Sperm. b> testis.

(12) a> Egg b> Ovaries.

(13) (a) testis.

(14) Ovaries.

(15) Sperm.

(16) Eggs.

(17) Penis.

(18) Uterus.

(20) IVF

(21) In Vitro Fertilization.

(22) 30 to 40 %

(23) Internal.

(24) Metamorphous.

(25) Silkworm

(26) Bug

(27) Binary fission.

(28) a> Amoeba, b> Hydra

(29) a> Budding, b> Binary fission.

(30) Cloning.

(31) Female.

(32) Clone

(33) Asexual and sexual

(34) a> true, b> false c> True d> True e>True f> false g>false h> True, i> False j> False k> True l> false m> false

(35) a> Reproduction, b> Gamets, C> Zygote d> fertilisation, e> ovum. f> Smaller g> Month. h> Oviparous. i> Viviparous ; oviparous, j> Metamorphosis. k> tadpole, l> Binary fission; budding. m> Cloning.

Short Answer Type Questions Answers

(36) (a) The basic difference between Asexual and Sexual Reproduction are:-

(i) In asexual reproduction only one parent is needed whoever in sexual reproduction two parent are needed.

(ii) In asexual reproduction sex cells (gametes) are n’t involved whoever in sexual reproduction gamets are involved.

(b)

  • Amoeba : Asexual method
  • Cats : Sexual Method
  • Humans : Sexual method
  • Hydra : Asexual method
  • Birds : Sexual method

(37) The fertilization which takes place inside the female body is called internal fertilization. For example : A man puts his sperms inside a women body , these sperms fertilize the egg inside the woman’s body.

The fertilization which takes place outside the female body is called external fertilization. For example : the males and females of frogs and fishes release their sperms and eggs in water in which they live.

(38)

a> In the human body an egg fertilize in Ovary.

b>  A fertilized egg develop into a baby in the human body is blastocyst.

(39)

a> Cow: Internal fertilization.

b> Frog: External fertilization.

c> Humans: Internal fertilization.

d> Fish: External fertilization.

e> Hen: Internal fertilization.

(40)  Female frogs lay hundred of eggs because all the eggs don’t get fertilised and hence don’t develop into net frogs.

(41) An unborn baby or an early stage of development is called Embryo.

No, we can not identify the body features in an embryo.

(42) When male gametes meets with female gametes then they both fuses with the nucleus of egg cell to form a new cell called zygote

But Zygote divides repeatedly to form a hollow ball of hundreds of cells which is called embryo.

But embryo grows and becomes a foetus and foetus grow and develops to form a new born baby.

(43) The various steps of sexual reproduction in  a animal are given below :

  • The male parent produces male gametes called sperms.
  • The female parents produces female gametes called eggs.
  • The sperm enters into the egg. The nucleus of sperm fuses with the nucleus of egg cells which is called embryo.
  • Embryo grows and becomes a foetus.
  • Foetus grows and develops to form a new baby animal.

(44)

(45) An unborn baby in the uterus at the stage when all the body parts can be identified is called a foetus.

It takes 38 weeks to development a human embryo to become a foetus.

(46) The process of transformation from an immature from of an animal in two or more distinct stages is called metamorphosis.

Two examples of metamorphosis are frogs and insects.

(47)

Viviparous

Oviparous

(i) Vivi = alive + Parous = bearing

(i) Ovi = relating to eggs + Parous = bearing

(ii) Those animals which give birth to young ones are called Viviparous animals.

(ii) Those animals which lay eggs from which younger’s are hatched later on are called Oviparous animals.

(iii) The human give birth to young ones so they are Viviparous animals.

(iii) The hen lays eggs from which young one hatched later on so the hen is an oviparous animals.


(48)

  • Frog : Oviparous
  • Human being : viviparous
  • Sparrow : oviparous.
  • Lizard : Oviparous.
  • Cow : viviparous
  • Dog : viviparous
  • Hen : Oviparous
  • Fish : Oviparous
  • Butterfly : oviparous
  • Cat : viviparous

(49)

a> Inside the mother : Human, Cat, Dog, Cow, Goat

b> Inside eggs which the mother lays : Frog, hen, lizard, sparrow, Duck

(50) The following steps how chicks are born :

  • After fertilization takes place inside the body of the hen, the fertilized egg divides repeatedly to form embryo which travels down the oviduct
  • As it travels down the oviduct, many protective layers are formed around the embryo. The hard shell that we see in a hen’s egg is the outermost protective layer.
  • After the hard egg shell is formed around the developing embryo, the hen finally lays the egg.
  • The hen then sits on the eggs to provide sufficient warmth to the eggs for the development of the chicks.
  • After the chick is completely developed, the egg shell breaks open automatically and the chicks comes out of it

It needs 21 days to develop embryo present in hen’s egg takes into a chick

(51)

  • Cow : Inside the mother’s body.
  • Ostrich :. In the egg laid by mother
  • Frog : In the egg laid by mother
  • Lizard : In the egg laid by mother
  • Deer : Inside the mother’s body
  • Cat : Inside the mother’s body
  • Snake : In the egg laid by mother
  • Tiger : Inside the mother’s body
  • Dog : Inside the mother’s body
  • Hen : In the egg laid by mother

(52)  Two animals which undergo Metamorphosis are : frogs and insects

Two animals which do not undergo Metamorphosis are : Hen, Dog

(53)

  • Cow : don’t undergo metamorphosis.
  • Butterfly : Undergo Metamorphosis.
  • Silk moth : Undergo Metamorphosis.
  • Humans : don’t undergo metamorphosis
  • Frog : Undergo Metamorphosis.
  • Housefly : Undergo Metamorphosis.
  • Sparrow : don’t undergo metamorphosis.
  • Hen : don’t undergo metamorphosis.
  • Mosquito : Undergo Metamorphosis.
  • Monkey : don’t undergo metamorphosis.

(54) (a) The cells involved in sexual reproduction are called gametes.

(b) sexual reproduction.

(c) zygote

(d) Fertilization

(55) 1>D  2>A 3>B  4>C

(56) The difference between internal and external fertilization are :

The fertilization which takes place inside the female body is called internal fertilization. For example : A man puts his sperms inside a women body , these sperms fertilize the egg inside the woman’s body.

The fertilization which takes place outside the female body is called external fertilization. For example : the males and females of frogs and fishes release their sperms and eggs in water in which they live.

(57) Cloning is the production of an exact copy of an animal by means of asexual reproduction.

Yes, gamets are involved in cloning. The nucleus os a normal body cell of the os the animal is transfered into an empty egg cell. The newly formed egg cell is allowed to develop normally. An exact copy of the animal is produced.

The two animals are sheep and cow which have been produced by cloning.

(58) The production of new organisms from the existing organisms of the same species is known as reproduction.

Reproduction is essential for the survival of a species on this earth.

(59) The production of a new organisms from a single parent without the involvement of sex cells is called asexual production.

Two methods of asexual reproduction are : Binary fusion and budding.

Binary fusion are Amoeba and budding is Hydra.

(60) An animal which is genetically identical to its parent is called a clone.

The famous clone is a sheep which name is Dolly.

LONG ANSWER TYPE QUESTIONS Answers         

(61) Fertilization is the action or process of fertilizing an egg or a female animal involving the fusion of male and female gametes to form a zygote.

When the sperms made  in the testes of man are introduced by penis into the women  body through vagina. The sperms enter into vagina, pass through the uterus and then go into the oviducts. The tail of sperms helps them in moving and reach the oviducts. One of the sperms enters the egg. The fusion of sperm with egg is called fertilization.

b>    

(62) (a) The couples who can produce sperms and eggs are helped to have babies by the IVF technique.

(b) The IVF technique in human beings are given bellow:

  • The eggs are removed from the ovary of women by laproscopy. In this operation, a small cut is made in the side of woman’s abdomen and an optical fibre tube is inserted into her body so that the doctor can see the ovary and take out the tiny eggs.
  • The woman’s husband provides the sperms and then mix with eggs in a glass dish to carry out fertilization. The fertilized eggs develop into embryos.
  • After about a week, one or more embryos are placed in the woman’s uterus . if the embryo gets implanted in the uterus successfully, then normal pregnancy occurs and a baby is born after about nine months.

(63)  a> Those animals which give birth to young ones are called viviparous animals.

Two Viviparous animals are Cow and Dog

b> Those animals which lay eggs from which young ones are hatched later on are called Oviparous animals.

(64) Amoeba reproduces with binary fission. In this reproduce system, they dividing its body into two parts. This happens as follows :

  • When the amoeba cell has reached its maximum size of growth, then first the nucleus of amoeba lenghthens and divides into two parts.
  • After that the cytoplasm of Amoeba divides into two parts, one parts around each nucleus.
  • Amoeba takes about an hour to divide into two daughter Amoebae
  • Two daughter amoebae produced here grow to their full size by eating food and then divide again.
  • Then daughter amoebae produced by the process of binary fission are identical to the parent amoeba

The labeled diagram of an amoeba reproduce are given below :

(65) Hydra is a multicellular animal.  The process of Budding in Hydra are given below :

  • First a small outgrowth called ‘bud’ is formed on the side of its body by the repeated divisions if its cells.
  • This bud then grows gradually to form a small hydra by developing a mouth and tentacles.
  • Finally the tiny new hydra detaches itself from the body of parent Hydra and lives as a separate organisms.
  • In this way the parent hydra has produced a new hydra.

The labeled diagram of a Hydra reproduce are given below

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  1. Very good
    It is very easy to learn by net explanations
    I was weak in science but now I am the 3 topper of the class

    1. Pandit…Rocket…

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