BIO 143 Chapter Notes - Chapter 9: Microtubule, Karyotype, Sister Chromatids
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Fall 2010—BIO143 STUDY GUIDE: Chapter 9
Chapter 9: The Continuity of Life: Cellular Reproduction
I. Why do cells divide?
A. Cell division transmits hereditary information to each daughter cell
1. What is the hereditary information in all living cells?
a. What is DNA composed of?
b. DNA is replicated into two identical copies before cell division
B. Cell division is required for growth and development
1. After cell division, daughter cells may differentiate, becoming specialized
2. Most multicellular organisms have three categories of cells. What are
C. Cell division is required for sexual and asexual reproduction
1. Sexual reproduction in eukaryotic organisms occurs when offspring are
produced by the fusion of sperm and egg from two adults
2. Asexual reproduction is when offspring are produced from a single adult
a. Producing offspring that are genetically identical to the parent
3. Both prokaryotic and eukaryotic cells have cell cycles (know and
understand the steps of prokaryotic and eukaryotic cell cycles)
II. What occurs during the prokaryotic cell cycle?
A. The DNA of a prokaryotic cell is contained in a circular chromosome; List all
five steps that occur during the cell cycle of prokaryotic organisms
1. Prokaryotic cells can divide as often as every 20 minutes
III. How is the DNA in eukaryotic chromosomes organized
A. Eukaryotic chromosomes are separated from the cytoplasm in a membrane-bound
1. The eukaryotic cells always have multiple chromosomes
B. The eukaryotic chromosome consists of a linear DNA double helix bound to
1. DNA is very long and totals about 6 feet in each human cell
2. The lenear DNA molecule is bound to packaging proteins called
a. Why are these proteins required?
b. DNA becomes folded into a dense structure during cell division
C. What are genes?
1. What are the three major regions of a chromosome?
a. Each gene occupies a specific place on a chromosome called a
b. Long stretches of repeated nucleotide sequences at the tips of
chromosomes are _____________? What is the main function of
this region of the chromosome?
c. Another structure on the chromosome which has two functions: