Friday, July 3, 2009

Chapter 4 Reproduction and Growth

Types of Reproduction

(1) Sexual reproduction
- using sex cells,which are called gametes
-involved male and female or two individuals
-humans,mammals,birds,reptiles,amphibians and fish

(2) Asexual reproduction
-without any gametes
e.g.-
binary fission
-spore formation
-budding

-vegetative reproduction
-Regeneration

In humans,the male gametes, called sperm or spermatozoa,produced by reproductive organs called testes.

Females = ova

The production of the two gamets calle dmeiosis.

Process of meiosis produces haploid gametes which are genetically not the same with the parental cells.

Spermatogenesis
Germinal epithelial cells (2n)
(through repeated mitosis)

Spermatogonia (2n)
(mitotsis)

Primary spermatocytes (2n)
(meiosis I)
http://science.tjc.edu/images/reproduction/spermatogenesis.jpg


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