2nd year

1. • Reproduction is the biological process by
which new individual organisms are produced.
• Reproduction is a fundamental feature of all
known life; each individual organism exists as
the result of reproduction.
• It is the process by which new organisms are
generated. It is the mechanism of species
continuation.

2. • Asexual reproduction is a primitive method of reproduction
without participation of a mate, gamete or fertilization.
• The common types of asexual reproduction in animals are:
1. Fission (ex: Amoeba, Plasmodium)
2. Budding (ex: Hydra, Sponges, Corals)
3. Regeneration (ex: Worms, Echinoderms)
4. Fragmentation (ex: Sponges)
5. Parthenogenesis (Honey bees, Ants, Wasps)
6. Cloning ( artificial method)

3. • Sexual reproduction is more common in unstable or
unfavorable circumstances.
• Significance
1. It is important to avoid genetic monotony.
2. It creates variations in species.
3. New species facilitate evolution of organisms.
• Necessities
1. Gametogenesis (Formation of gametes)
2. Mating or copulation (Contribution of gametes)
3. Fertilization (Fusion of gametes)

4. • A pair of testes Cowpers
gland
• Epididymis
• Vas deference
• Urethra
• Penis
• Three types of accessory
glands
1. Seminal vesicles
2. Prostate gland
3. Cowper’s gland

5. Structure of Testes
Testes (testicles):
• These are small, solid, oval bodies packed with tightly coiled
Seminiferous tubules which produce sperms and androgens
(male sex hormones).
• The most common androgen is called testosterone. Androgens
cause males to develop male secondary sexual characteristics at
puberty.
Scrotum:
• Before birth, testes descend down in a pouch like structure that
hangs behind the penis.
• It holds and protects the testes and allows the development of
sperms at low temperature than body temperature.
• It also contains numerous nerves and blood vessels.
• The penis and scrotum makes the external genetalia.

6. • The testes consist of a mass of coiled tubes called
semeniferous tubules in which the sperms are formed
by meiosis. Cells lying between the semeniferous
tubules produce the male sex hormone
• When the sperm are produced they are stored in an
about 6m long, thin tube, the where they
become mature and motile before moving to
the .
• The two sperm ducts join the just below the
bladder, which passes through the and transports
both sperm and urine.

7. Accessory Glands
• Three different glands may be involved in producing the
secretions which mixes with sperm and make male genital
fluid semen or seminal fluid.
:When present they produce secretions
that make up much of the volume of the semen, and
transport and provide nutrients for the sperm.
2. P :It produces an alkaline secretion that
neutralizes the acidity of the male urethra and female
vagina.
It has various functions in different
species. Its secretions may lubricate and neutralizes the
acidity of urethra caused by the passage of urine.

9. Spermatogenesis

10. Structure of a Sperm
A Sperm consists of three parts:
a head consisting mainly of the nucleus,
a midpiece containing many mitochondria
to provide the energy and a tail that
provides propulsion.
tail

11. • A pair of ovaries
• Fallopian funnel
• Uterus
• Cervix
• Vagina

13. • The ovaries are a pair of oval or almond-shaped
structures which lie on either side of the uterus and just
below the opening to the fallopian tubes.
• In addition to producing eggs or "ova," the ovaries
produce female sex hormones called estrogen and
progesterone.
• The ovaries, unlike the testes, does not manufacture the
sex cells rather 200,000 oocytes are present in each
ovary at the time of birth which are contained in sac-like
depressions in the ovaries.

14. • The fallopian tube extends from the uterus to the
ovary. This tube carries eggs and sperm and is where
fertilization of the egg, or "ovum" takes place.
• The fallopian tubes lie in the pelvic portion of the
abdominal cavity and each tube reaches from an ovary
to become the upper part of the uterus.
• This funnel-shaped tube is about three inches in length.
The larger end of the funnel is divided into feathery,
finger-like projections which lie close to the ovary.
• Their beating projections, along with muscle
contractions, force the ovum down the funnel's small
end, which opens into the uterus.

15. The Uterus
• The uterus is a hollow, pear-shaped organ
that is the home to a developing fetus.
• The uterus is divided into two parts: the
, which is the lower part that opens
into the vagina, and the main body of the
uterus, called the
• The lower one-third of the uterus is the
tubular "cervix," which extends downward
into the upper portion of the vagina.

16. • The vagina is a muscular passage which forms
a part of the female sex organs and which
connects the neck of the uterus called cervix
with the external genitals.
• The vagina has three functions:
1. as a reception for the sperms
2. as outlet for blood during menstruation
3. as a passageway for the delivery of feotus
at birth.

17. Oogenesis