Chapter 8: How Cells Reproduce
We intuitively consider the fusion of two gametes to create a single, fertilized, zygote as
the beginning of an organism's life cycle. The cell must go through several (maybe
several hundred) rounds of cell division to produce the large population of cells needed to
construct the body of a multicellular organism. Throughout this process of cell division
the genetic material must be replicated, condensed and partitioned faithfully into daughter
cells. This type of cell division is called "mitosis".
For sexually reproducing organisms, the gametes mentioned above are created in gonads
by a specialized type of cell division that must reduce the amount of genetic material by
half. This is "meiosis". Our body (somatic) cells are diploid, our gametes are haploid.
*figure 8.5 and 8.13
1. What is the ultimate purpose of mitosis?
2. In animals, all of the following processes are the result of mitosis except
A. growth of the young organism.
B. asexual reproduction (in some cases).
C . repair of injured tissue.
D. production of the gametes.
3. Think about the following statement carefully as you complete the blanks.
During the _____ phase of _____________ of the cell cycle, the chromosomes
undergo replication, so that after this phase each chromosome is now composed
of two ______________ joined at the ________________.
4. During what stage(s) does synapsis and crossing-over take place in meiosis?
5. What is the earliest stage at which the daughter cells are haploid?
6. At what stage can independent ( random) assortment first be seen? Explain