Male and Female reproductive systems of mammals

advertisement
Male and Female
Reproductive Systems of
Mammals
1. Male reproductive
system
• The two testes- The sexual glands
where sperm cells and a male
hormone are produced.
• The two sperm ducts- The pathways
for the sperm cells from the testicles
to the urethra.
• The seminal glands- Produce liquid
called semen. It is rich in nutrients
important for the sperm cells to move
and survive.
• The urethra- The tube that carries
urine and sperm to the outside of the
body.
• The penis- The organ of copulation
2. Female reproductive
system
• The ovaries -The sexual
glands where ova and the
female hormones are
produced.
• The oviducts- The pathway for
the ova from the ovary to the
uterus and site of fertilization.
• The uterus- The site of the
fetus development.
• The vagina- The female organ
of copulation.
3. The reproductive cells (gametes)
a/ The male gametes:
Sperm cells
b/ The female gametes:
Egg cells (ova)
4. Fertilization
• a/ What is fertilization?- Fertilization is the union of an egg and sperm,
usually occurring in the oviduct. The result of this union is the production of a
zygote.
• b/ Steps of the formation of the zygote
- The sperm cell penetrates the egg cell by dissolving part of its envelope.
- The nucleus of the sperm cell mixes with the nucleus of the egg cell.
- The zygote is formed.
7. Kinds of fertilization
• a/ External fertilization (in frogs)
- Clasping by the male, stimulates the female to lay 500 to 5000 eggs.
- The male fertilizes the eggs by releasing semen in water.
• b/ Internal fertilization (in mammals)
- The male covers the female.
- The male’s penis penetrates the female’s vagina. In this way, the
sperm cells are directly introduced into the uterus.
- Fertilization takes place in the oviduct.
8. Kinds of animals according to the eggs
development
• a/ Oviparous animals: They lay eggs. These eggs develop outside the
female body. The oviparous eggs are very big and rich in nutrients
important for the development of the embryo.
The oviparous females do not have uterus.
Examples: Birds, reptiles, fish
• b/ Viviparous animals: In these animals the fertilized egg develops
inside the mother’s uterus. Their eggs are very small and poor
in nutrients because the mother provides all the necessary
nutrients to the embryo.
Examples: All mammals
• c/ Ovoviviparous animals: They produce eggs rich in nutrients. But the
development of the youngsters occurs inside the mothers body, in the
oviduct. The ovoviviparous animals do not have uterus.
• Example: The viper
Download
Related flashcards
Create Flashcards