Nature

Nature

วันจันทร์ที่ 19 กันยายน พ.ศ. 2554

Reproductive organs

3.9a - Male reproductive organ
Structure and uses:

  • Bladder - Store Urine 
  • Tesis - Meisosis Germinate sperm cells 
  • Epididymis - Store Sperm cells 
  • Vas deferens - Sends Sperm cells to the penis 
  • Prostate - 30% semen 
  • Seminal Vesicles - 70% semen 
  • Uretha - Common tube, takes semen ou of the penis 
  • Penis - Carry sperm cells into the vagina 
3.9b Female reproductive organ 
Structure and uses: 
  • Ovary - Meiosis/ produces eggs
  • Oviducts - Carries eggs 
  • Uterus - wall of uterus made of muscle (stretch for pregenancy)
  • Lining of the Uterus - development of embryo/egg
  • Uterus Space - Embryo developes here 
  •  Cervix - Where sperm cells enter
  • Vagina -allows sperm cells to come in  

วันพฤหัสบดีที่ 1 กันยายน พ.ศ. 2554

3.24c Stages of Mitosis

First the cell starts of in the inter phase where the chrmosones begin to replicate thier DNA.
This causes a pair of Chromosomes that are held together by a centremere this is called a Chromatids.




At this point their are 46 pairs of Chromatids in all, which means 92 individual Chromosomes
Then Begins the Prophase where the Nucleus starts to deteriorate revealing the Chromosomes
The late Prophase is when strands of protien start to from, these are called swindle cords
The Chromatids then get attached to the swindle cords through the centermere and they start to shift towards the equator of the cell, this is the Metaphase
The the Anaphase begins and the cells begin to expand and the swindle cords slowly pull the chromatids apart.
After this is the Telaphase where nucleus start to from around the different sets of chromosones and creates two nucleus




Then there is Cyto-Kinesis which is when the two nucleus split out of the cell and create to identical cells