UNIT 7 REPRODUCTION

UNIT 7 REPRODUCTION

7.1 Reproduction

Living things can produce offspring through asexual and sexual reproduction.

Asexual reproduction require one parent. The young produced a clone of the parent.

Several asexual reproduction method in animals: Budding, formation of internal buds, fragmentation, regeneration.

Sexual reproduction require two organism: a male and a female.

Mature male organism produce reproductive cell called sperm cell. Mature female produce egg.

Sperm cell and egg fuse and develop into the young.

7.2 How human life begins

Sperm cell meets an egg and fuse. The fusion between male and female reproductive cells is called fertilization. Many sperm cells reach the egg, but only one sperm cell can fertilize the egg. The fertilized egg starts to form more cells. It attaches to the wall of mother womb and continue to develop and grow. The developing baby draws nutrients from mother’s blood through the umbilical cord. About nine months after fertilization the baby is born.

7.3 Fertilized egg

External fertilization

The eggs fertilized outside the body of the female. The lays its egg and the male releases its sperms on the egg. Example: frog, fish.

Note:  External fertilization reduce the chances survival of the developing eggs.

Internal fertilization.

The egg fertilized inside the body of the female. Example: Human being, leopard and insects.

 Note:  Internal fertilization increase the chances of successful sexual reproduction.