Saturday, March 15, 2008
Fri-Day 1
Bio- we further discussed meiosis by showing the details of the first primary sex cell division (meiosis I), which changes the number of chromosomes per cell from the diploid number (2n, or 46 in humans) to the haploid number (n, or 23 in humans). After meiosis I, the chromosomes in the two daughter cells are double stranded BUT not identical due to the crossing over that occurred in prophase I. In meiosis II, these two cells divide again without any chromosome replication; the double stranded chromosomes each become two separate chromosomes, which are equally divided into the two daughter/gamete cells. Overall, four gametes are made from the one primary sex cell. In males, each gamete gets an equal quantity of cytoplasm from each division (cytokinesis) so that the four sperm cells are equal size. However, in females, both cell division in meiosis I and II respectively, have extremely unequal cytoplasm division so that only ONE egg/ovum forms along with three "polar bodies". The egg and three polar bodies do have the haploid/monoploid number of chromosomes.
We then saw a video from NOVA on PBS that provided thorough detail on human reproduction and fetal development from gamete formation through delivery of a baby.
Chem 7- we completed several more stoichiometry problems involving decomposition, single replacement and double replacement.
Chem 8/9- we completed several more stoichiometry problems involving decomposition, single replacement and double replacement. We also finished the writeup of our hydrate lab and finished the weighing procedure from our stoichiometry/conservation of mass lab.
We then saw a video from NOVA on PBS that provided thorough detail on human reproduction and fetal development from gamete formation through delivery of a baby.
Chem 7- we completed several more stoichiometry problems involving decomposition, single replacement and double replacement.
Chem 8/9- we completed several more stoichiometry problems involving decomposition, single replacement and double replacement. We also finished the writeup of our hydrate lab and finished the weighing procedure from our stoichiometry/conservation of mass lab.
# posted by C @ 5:23 PM 
