Scribe Post 1/5/12

Today in class we watched part of a Bill Nye video, then took notes on gametogenesis, and ended class with the mammalian gametes lab (p. 35-38).

Homework:

1. Finish Lab (p. 35-58)


2. Pages 15-18 in UP
3. Study for test
4. Study for final

NOTES

Reproduction and Development

Gametogenesis (p. 5-8)

This section was mostly about how we make gametes

• Gametogenesis is the production of gametes


• Gametes are half of a diploid cell(haploid) that is developed by meiosis

We took notes on female gametogenesis first.

• OOGENESIS is the development of eggs within the ovaries


• AT BIRTH a follicle contains a primary (1 degree) oocybe which is dormant
• OOCYBE is a diploid cell that pauses it meiosis prophase 1
• FSH (follicle simulating hormone) triggers the devlopment of the follicle
• Eventually the follicle completes meiosis 1 and moves on to meiosis 2
• Only 1 secondary(2 degree) oocyte receives most of the cytoplasm
• Polar Body is the cell that gets little cytoplasm
• Ovulation starts when the pituitary gland has secreted luteinizing hormone
• Meiosis 2 is completed only if a sperm fuses with the 2 degree oocyte
• A second polar body is formed due to meiosis 2

Male Gametogenesis

• Spermatogenesis is the formation of the sperm cell
• Formed in seminiferous tubules
• Mitosis is used so that the testes does not run out of sperm to copy
• Meiosis produces 2 secondary spermatocytes
• Then 4 spermatids are created in meiosis 2
• Sperm fully mature(grow int their shape) at the epididymis and then stored until ejaculation

• 

These are the differences between male and female gametogenesis

• FEMALE
• Ovaries
• produces until metapause
• 1 gamete from parent cell
• Large
• Nonmotile and full of nutrients
• Completed by stimulation of sperm cell
• MALE
• Testes
• Produced everyday until death
• 4gametes from parent cell
• Small
• Motile and little nutrients
• Completed before sperm leaves the testes

Thanks, Michael

Next Scribe: Helen