Reading assignments are from 'Biology', Seventh Edition by Campbell and Reece.               

Review the structure of nucleic acids on p. 87-88.  Also refer to Dr. Hamilton's handout on Organic Molecules.

1. Give a very brief description of the double helix structure of DNA (use Fig. 5.27on p. 88 and Fig. 16.7a on p. 297). 
   It is not necessary to give the structure of the sugar-phosphate backbone.  Why are the 2 polynucleotide strands which make up a DNA molecule called 'complementary'?
2. Before cell division these 2 strands separate and each directs the formation of a new complementary strand.  How does this occur and why is each original strand called a 'template'?

• what a checkpoint is.
• that fluctuating activities and quantities of regulatory molecules (proteins) are the master controls of the cell cycle.
• that both internal (inside the cell) and external signals also affect the cell cycle.

3. Are human somatic cells haploid or diploid?  How many chromosomes are in each of these cells?  Answer these questions for human gametes also.  What is an organism's genome?
4. What is chromatin?  What is the difference between chromatin and chromosomes?
5. A non-replicated chromosome is made up of 2 polynucleotide strands.  How many 'strands' are in a replicated chromosome?  How many 'strands' are in one sister chromatid?
6. Interphase and the mitotic phase are 2 parts of the cell cycle.  What are the subphases of interphase and briefly describe what occurs in each subphase.
7. The mitotic phase of the cell cycle is a 'continuum of change'. What does this mean and why do we need to divide mitosis into phases?  What are the phases of mitosis?
8. What is the mitotic spindle made up of and where and when does it begin to form?
9. What are the functions of the mitotic spindle?
10. What is a centromere?  What is a kinetochore? How many kinetochores are present in a replicated chromosome? 
11. What is the metaphase plate (is it a physical structure?)?  Explain the mechanism by which the kinetochores help align the chromosomes along the metaphase plate.
12. Briefly describe cytokinesis in an animal cell and in a plant cell.
13. Are most of the cells in the human body actively dividing?  What is the phase name of this non-dividing state?
14. Help!  I'm confused!  Please recap the differences between:
• chromatin
• a chromosome
• a replicated chromosome
• a non-replicated chromosome
• a chromatid