The document is a science presentation about reproduction in animals. It discusses various topics like what is reproduction, the importance of reproduction, types of reproduction including asexual and sexual reproduction. It describes the male and female reproductive organs and gametes. It explains the process of fertilization, development of the embryo, viviparous and oviparous animals. It provides examples of asexual reproduction and discusses metamorphosis.

1. SCIENCE PPT
Name-Samba Ghosh
Class -08
Roll No. – 31
Topic – Reproduction in
Animal
Subject - Science

3. WHAT IS REPRODUCTION?
THE PRODUCTION OF NEW ORGANISM FROM THE EXISTING
ORGANISM OF THE SAME SPECIES IS KNOWN AS REPRODUCTION.
REPRODUCTION IS ESSSNTIAL FOR THE SURVIVAL OF A SPECIES
ON THIS EARTH.
REPRODUCTION BY HUMANBEINGS ENSURES THAT THE HUMAN
SPECIES WILL CONTINUE TO EXIST ON THIS EARTH FPR ALL THE
TIME TO COME.
REPRODUCTION GIVE RISE TO MORE ORGANISM WITH THE SAME
BASIC CHARACTERISTICS AS THEIR PARENTS .
THE NEWLY BORN ANIMAL ( OR NEWLY HATCHED ANIMALS )IS
CALLED YOUNG ONES .
TOPIC :- REPRODUCTION IN ANIMALS

4. • TOPIC :- REPRODUCTION IN ANIMALS
• WHAY IS REPRODUCTION?
• THE PRODUCTION OF NEW ORGANISM FROM THE EXISTING
ORGANISM OF THE SAME SPECIES IS KNOWN AS REPRODUCTION
• REPRODUCTION IS ESSSNTIAL FOR THE SURVIVAL OF A SPECIES ON
THIS EARTH.
• REPRODUCTION BY HUMANBEINGS ENSURES THAT THE HUMAN
SPECIES WILL CONTINUE TO EXIST ON THIS EARTH FPR ALL THE
TIME TO COME.
• REPRODUCTION GIVE RISE TO MORE ORGANISM WITH THE SAME
BASIC CHARACTERISTICS AS THEIR PARENTS .
• THE NEWLY BORN ANIMAL ( OR NEWLY HATCHED ANIMALS )IS
CALLED YOUNGONES .
METHODS OF REPRODUCTION
THERE ARE TWO TYPES OF REPRODUCTION:-
1. ASEXUAL ROPRODUCTION
2. SEXUAL REPRODUCTION
1. ASEXUAL REPRODUCTION:- THE
PRODUCTION OF A NEW ORGANISM
FROM A SINGLE PARENTS WITHOUT THE
INVOLVEMENT OF SEX CELL( OR GAMETS
) IS CALLED SEXUAL REPRODUCTION .
E.G:-BINARY FISSION IN AMOEBA
2. SEXUAL REPRODUCTION:- THE
PRODUCTION OF A NEW ORGANISM
FROM RWO PARENTS BY MAKING USE
OF THEIR SEX CELL (OR GAMETS)IS
CALLED SEXUAL REPRODUCTION .
E.G:- HUMAN, FISH, FROG.

5. MALE AND FEMALE
AN ANIMAL HAVING MALE SEX CELL CALLED SPERMS IN ITS
BODY IS CALLED MALE.
AN ANIMAL HAVING FEMALE SEX CELL CALLED EGGS
(OR OVA) IN ITS BODY IS CALLED FEMALE GAMETS.
THE CELL INVOLVE IN SEXUAL REPRRODUCTION IS CALLED GAMETS
1. THE MALE GAMETS IN ANIMALS IS CALLED SPERMS.
2. THE FEMALE GAMETS IN ANIMALS IS CALLED EGG OR OVA.
SPERMS :- THE SPERM IS THE MALE GAMETS. IT IS A SINGLE CELL WITH THE
USUAL CELL COMPONENT LIKE NUCLEUS CELL MEMBRANE IS CALLED SPERM.
EGG (OR OVA) :- THE EGG IS A FEMALE GAMETS . IT IS A SINGLE CELL. THE
HUMAN EGG IS ROUND IN SHAPEAND ABOUT 0.15mm IN DIAMETRE.
ZYGOTE
THE NEW CELL WHICH IS FORMED BY THE FUSION OF A MALE GAMET AND A
FEMALE GAMET IS CALLED ZYGOTE . ZYGOTE IS A AINGLE CELL.

6. FERTILISATION
THE FUSION OF A MALE GAMETE
WITH A FEMALE GAMETE TO FORM A
ZYGOTTE DURING SEXUAL
REPRODUCTION IS CALLED
FERTILISATION. ZYGOTE IS
ACTUALLY A FERTILISED EGG. IT IS
OF TWO TYPES.THESE ARE AS
FOLLOWS:
1. ITERNAL FERTILISATION
2. EXTERNAL FERTILISATION

8. SEXUAL REPRODUCTION IN ANIMAL
THE WHOLE PROCESS OF SEXUAL REPRODUCTIONIN ANIMALS INVOLVESTHE
FORMATION OF SPERS AND EGGS, JOINING TPGETHER OF SPERMS AND EGG TO FORM
A FERTILISHDE EGG (ZYGOTE) AND GROWTH AND DEVELOPMENT OF TOFORMA BABY
ANIMAL .IT IS THE PROCESS OF SEXUAL REPRODUTION IN ANIMAL.
i. THE MALE PARENTS PRODUCES MALE GAMETS CALLED SPERMS.
ii. THE FEMALE PARENTS PRODUCE FEMALE GAMETS CALLED OVA.
iii. THE SPERMS ENTER INTO THE EGG . THE NECLEUS OF SPERMS FUSESWITH THE
NUCLEUS OF EGG CELL TO FORM A NEW CELL CALLED ZYGOTE.
iv. THE ZYGOTE DIVIDED REPETEDLLY TO FORM A HOLLOW BALLOF HUNDREADES OF
CELLS WHICH IS CALLED EMBRYO.
v. EMBRYO GROWS AND BECOMES A FOETUS .
vi. FOETUS GROWSAND DEVELOPES A NEW BABY ANIMAL.

9. THE MALE REPRODUCTIVE SYSTEM
THE MALE REPRODUCTIVE ORGANE CONSIST OF THE
FOLLOWING ORGANS
i. TESTES
ii. SCROTAL SACS
iii. EPIDIDYMIS
iv. SPERM DUCT
v. SEMINAL VESICLES
vi. PENIS
 TESTES ARE THE REAL REEPRODUCTIVE ORGANE
IN MALE
 TESTES MAKE MALE GAMETES CALLED SPERMS
 TESTES PASSES THE SPERMS FROM THE MALE
BODY TO THE FEMALE BODYT THAT CAUSES
FUSION.

10. FEMALE REPRODUCTIVE ORGAN:-
THE FEMALE REPRODUCTIVE SYSTEM CONSIST OF THE FOLLOWING:-
i. OVARIES
ii. OVIDUCTS
iii. UTERUS
iv. VAGINA
OVARIES ARE THE REAL REPRODUCTIVE ORGANES IN THE FEMALE .
 OVARIES MAKE THWE FEMALE GAMETS CALLED EGG (OR OVA).
 IN HUMAN BEINGS ,OBE MATURE EGGIS RELEASED INTO
OVIDUCT EVERY MONTHBY ONE OF THE OVARIES
 THE FERTILISATION OF EGG BY A SPERMTAKES PLACEIN THE
OVIDUCT.

12. Fertilization:
The first step in the process of reproduction is the fusion of a sperm and an ovum. When
sperms come in contact with an egg, one of the sperms may fuse with the egg. Such fusion of
the egg and the sperm is called fertilization. During fertilization, the nuclei of the sperm and
the egg fuse to form a single nucleus. This results in the formation of a fertilized egg or zygote.
The process of fertilization is the meeting of an egg cell from the mother and a sperm cell from
the father. So, the new individual inherits some characteristics from the mother and some
from the father.
Fertilization which takes place inside the female body is called internal fertilization. Internal
fertilization occurs in many animals including humans, cows, dogs and hens.
In many animals fertilization takes place outside the body of the female. In these animals,
fertilization takes place in water.
During spring or rainy season, frogs and toads move to ponds and slow flowing streams. When
the male and female come together in water, the female lays hundreds of eggs. Unlike hen’s
egg, frog’s egg is not covered by a shell and it is comparatively very delicate. A layer of jelly
holds the eggs together and provides protection to the eggs.
As the eggs are laid, the male deposits sperms over them. Each sperm swims randomly in
water with the help of its long tail. The sperms come in contact with the eggs. This results in
fertilization. This type of fertilization in which the fusion of a male and a female gamete takes
place outside the body of the female is called external fertilization. It is very common in
aquatic animals such as fish, starfish, etc

13. FERTILIZATION

14. Development of Embryo
Fertilization results in the formation of zygote which begins to
develop into an embryo. The zygote divides repeatedly to give rise to
a ball of cells. The cells then begin to form groups that develop into
different tissues and organs of the body. This developing structure is
termed an embryo. The embryo gets embedded in the wall of the
uterus for further development.
The embryo continues to develop in the uterus. It gradually develops
the body parts such as hands, legs, head, eyes, ears, etc. The stage of
the embryo in which all the body parts can be identified is called a
foetus. When the development of the foetus is complete, the mother
gives birth to the baby.
In animals which undergo external fertilization, development of the
embryo takes place outside the female body. The embryos continue
to grow within their egg coverings. After the embryos develop, the
eggs hatch.

16. Viviparous and Oviparous Animals
Some animals give birth to young ones while
some animals lay eggs which later develop into
young ones. The animals which give birth to
young ones are called viviparous animals. Those
animals which lay eggs are called oviparous
animals.

18. Metamorphosis is a biological process by which an
animal physically develops after birth or hatching,
involving a conspicuous and relatively abrupt
change in the animal's body structure through cell
growth and differentiation.

20. Asexual Reproduction
This type of reproduction in which only a single parent is involved is called
asexual reproduction.
In each hydra, there may be one or more bulges. These bulges are the
developing new individuals and they are called buds. In hydra too the new
individuals develop as outgrowths from a single parent. Since new individuals
develop from the buds in hydra, this type of asexual reproduction is called
budding.
Another method of asexual reproduction is observed in the microscopic
organism, amoeba. Amoeba is a single-celled organisms. It begins the process
of reproduction by the division of its nucleus into two nuclei. This is followed by
division of its body into two, each part receiving a nucleus. Finally, two
amoebae are produced from one parent amoeba. This type of asexual
reproduction in which an animal reproduces by dividing into two individuals is
called binary fission.

21. EXAMPLES OF ASEXUAL REPRODUCTION

22. . What is test-tube baby?
Answer: Oviducts of some women are blocked due to which
these women are not be able to bear babies. In these type of
cases IVF or in vitro fertilization is done in which freshly
released egg and sperms are kept them together for a few
hours.
Zygote is allowed to develop for about a week and then it
placed in the mother’s uterus and the baby is born and this
technique is called as test-tube babies.
Q. What is implantation?
Answer: The close attachment of the embryo with the walls of
uterus is called implantation.