Chapter Eight: The Cellular Basis of Reproduction and Inheritance

Questions:

1. Why is binary fission classified as asexual reproduction?

  A: Because the genetically identical offspring inherit their DNA from a single parent.

2. Contrast cytokinesis in animals with cytokinesis in plants?

  A: In animals, cytokinesis involves a cleavage furrow in which contracting microfilaments pinch the cell in two. In plants, it involves formation of a cell plate, a fusion of vesicles that forms new membrane and walls between the cells.

3.  What is metastasis?

  A: Metastasis is the spread of cancer cells via the circulatory system from their original site of formation to sites in the body.


Five Main Facts From The Reading:

1. Cells arise only from preexisting cells.
2. Prokaryotes reproduce by binary fission.
3. Chromosomes of eukaryotes duplicate with each cell division.
4. Anchorage, cell density, and chemical growth factors affect cell division.
5. Cancer is caused by non-regulation growth in the cells.

This image shows the cell in the final stage of reproduction: cytokinesis, or seperation.





What is Leukemia? http://www.youtube.com/watch?v=JNh1u7P7Ql8


Ten Key Terms:

Asexual Reproduction - the creation of genetically identical offspring by a single parent without the use of sperm or egg.
Chromosomes - the structures that contain most of the organism's DNA.
Sexual Reproduction - offspring that generally resemble their parents more closely than they resemble unrelated individuals of the same species, produced by two parents with the use of sperm and egg.
Chromatin - chromosomes existing as a diffuse mass of long, thing fibers.
Sister Chromatids - identical copies of the DNA molecule.
Centromere - a small "ball" that joins the two chromatids together.
Cell Cycle - an ordered sequence of events that extends from the time a cell is first formed until it's own division into two cells.
Mitotic spindle - a football shaped structure of microtubules that guides the seperation of the two sets of daughter chromosomes.
Centrosomes - clouds of cytoplasmic material that in animal cells contain centrioles.
Anchorage Dependence - most animal cells exhibit this, they must be in contact with a solid surface to divide.


This chapter took us through two cell cycles, Mitosis and Meiosis.. both related to cell division. It explored the steps that lead to cell division: Interphase, Prophase, (Prometaphase) Metaphase, Anaphase, Telophase and Cytokinesis. It explained the differences between Meiosis and Mitosis and well as the differences of cell division in plant and animal cells.