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Sexual reproduction
1.
2.
Sexual reproduction is theproduction of new offsprings from
two parents.
Sexual reproduction is the
combination of one set of genetic
material from two organisms of the
same species, but opposite sex,
resulting in a new organism with new
gene combination.
3.
GAMETES•Sexual reproduction occurs by
means of gametes.
•They are produced in reproductive
organs by means of meiotic cell
division
Gametes have n number of
chromosome.
4.
5. Organs which produce gametes are called Gonads.
•Organs which producegametes are called Gonads.
•Male gonad is called testes
that produce sperm .
Female Gonad is called ovary
that produce egg.
6. Production of Gametes
Production of male or femalegametes are called
Gametogenesis.
Especially production of sperm
is called Spermatogenesis.
Production of egg is called
oogenesis.
7. FERTILIZATION
The union of egg and sperm iscalled FERTILIZATION.
The cell that is formed from union
of an egg and sperm is called
ZYGOTE.
Gametes have n number of
chromosome and zygote has 2n
number of chromosome.
8. Steps of Sexual Reproduction
testisovary
Meiosis
sperms
Meiosis
fertilization
zygote
embryo
foetus
baby
eggs (ova)
9. POLLINATION
10.
•Trаnsfer of pollen from antherto stigma is called pollination.
• Pollination occurs by means of
wind,water, insects and other
animals
11.
12. After pollination;
A pollen tube grows down throughthe stigma and stylus into the
ovary.
The tube nucleus controls the
formation of pollen tube.
Then pollen tube enters the ovule
through the microphyle
The tube nucleus and generative
nucleus pass from pollen grain to
13. FERTILIZATION
The generative nucleus is divided intotwo sperm nuclei in the pollen tube.
2 Sperm nuclei enter the embryo sac.
One sperm fertilizes to egg cell to form
ZYGOTE.
Other sperm fuses with pollar nüclei to
form triploid (3n) ENDOSPERM.
This type of fertilization is called
Double Fertilization.
14.
15. SEED AND FRUITS
After the fertilization, eachovule develops to seed.
The ovary develops to fruit.