Reproductive Systems3-D male reproductive System 3-D female reproductive

System

Testes TissueSperm production occurs

in seminiferous

tubules

See Fig. 46.12

Testes TissueSperm production occurs

in seminiferous

tubules

At puberty, testosterone

production begins

in interstitial cells

See Fig. 46.12

Testes TissueSperm production occurs

in seminiferous

tubules

Sertoli cells regulate

sperm production &

nourish developing

sperm

See Fig. 46.12

Testes TissueSperm production occurs

in seminiferous

tubules

Spermatozoa are

produced by

spermatogonia

See Fig. 46.12

Fig. 46.11

http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter28/animation__spermatogenesis__quiz_1_.html

Animation: Spermatogenesis

http://media.pearsoncmg.com/bc/bc_campbell_biology_7/media/interactivemedia/activities/load.html?46&A

Spermatogenesisproduction of sperms occurs in the

testes in seminiferous tubulesfirst stage of spermatogenesis mitotic

cell divisions of primordial germ cells to produce spermatogonial cells

spermatogonial cells then undergo a period of growth to form primary spermatocytes

each primary spermatocyte then undergo two meiotic cell divisions: meiosis I to produce secondary

spermatocyte & meiosis II to produce spermatids

spermatid cells then undergoes differentiation to form sperm cells

Sperm cells are nourished by Sertoli cells

each primary spermatocyte produce 4 sperm cells with haploid number of chromosomes i.e. 23 chromosomes

Structure of the sperm

Animation: Oogenesis

Oogenesis oogenesis is process by which female gametes (egg cells) are produced in the ovary

it begins during fetal development when oogonia are formed from primordial germ cells by mitosis

Oogonia undergoes growth to form primary oocytes

primary oocyte begin first meiotic division but stop in Prophase I until on set of puberty

at puberty some follicles develop each month in response to FSH produced by pituitary gland

primary oocyte completes first meiotic division to forms two cells of different sizes due to unequal distribution of cytoplasm

the one with less cytoplasm become the first polar body which eventually degenerates

the larger cell becomes secondary oocyte and proceeds to meiosis II & stops at prophase II

meiosis II is completed if cell is fertilized forming an ovum and second polar body

structure of the ovum

Animation: Comparison of Spermatogenesis and Oogenesis

Comparison Between spermatogenesis & oogenesis

spermatogenesis oogenesismillions sperms produced

per dayfour sperms of equal

division of the cytoplasm & no polar bodies

begins at puberty i.e. at sexual maturity

occurs throughout adult life

sperms are produced continuously & released during ejaculation

occurs in the testesspermatogenesis involves

meiotic cell divisionproduce haploid cells

one ovum per 28 day menstrual cycle

one ovum, unequal division of the cytoplasm, 2 polar bodies

begins during foetal development

ends at menopauseovum released during

ovulation in the middle of the menstrual cycle

occurs in the ovaries oogenesis involves

meiotic cell divisionproduce haploid cells

http://bcs.whfreeman.com/thelifewire/content/chp43/4302001.html

Fertilisation sperm cell approach the egg in oviduct

Acrosome of sperm cell releases hydrolytic enzymes which digest jelly layer (zona pellucida) of the egg

sperm cell head (acrosomal process) extends through jelly to vitelline membrane (egg’s plasma membrane)

binding proteins on surface of acrosome attach to receptors on vitelline membrane

sperm plasma membrane fuses with egg plasma membrane

fusion of plasma membranes causes depolarization of egg plasma membrane i.e. cortical reaction which bars other sperm cells from fusing with membrane

sperm nucleus enters egg (secondary oocyte) after dissolution of nuclear membranes resulting in combination of genetic material

Revision QuestionsDraw a labelled diagram of the

adult female reproductive system. [4]

Draw a labelled diagram of an adult male reproductive system. [6 ]

Explain the processes involved in oogenesis in humans. [9]

Draw the structure of a mature human egg. [4]

Explain the role of hormones in the regulation of the menstrual cycle in human females. [8]

Draw a labelled diagram of a mature sperm. [5]

Outline the process of spermatogenesis in humans. [5]

Compare the process of spermatogenesis and oogenesis. [7]

Describe the process of fertilization in humans. [8]

Describe the development of the early human embryo. [5]

Outline the regulation of pregnancy by two named hormones. [4]