1. Unit 7 Review Questions

2. Describe the claim that Watson and Crick examined and how they proved this claim. Describe the claim that Hersey and Chase researched and what evidence they corrected to prove this claim. If a DNA molecule has 40% cytosine, how much adenine does this molecule have? Who performed the first such test? What claim did they test with this? Describe what evidence Meselson and Stahl collected to support the claim that DNA replication is semiconservative. Provide a reasoning to connect the evidence from the previous question with the claim.

3. Determine the chromosome numbers if the diploid number of the organism is 50: – Number of chromosomes in haploid cells: – Number of chromatids in a haploid cell during metaphase: – Number of chromatids during metaphase I, meiosis: – Number of chromosomes at the end of metaphase II List three processes that can result in genetic variety Describe the structure of DNA

4. Describe the structure of chromosomes: Compare and contrast mitosis in plants and animals Give 5 differences between mitosis and meiosis Why does the cell cycle need to be regulated? Describe the process of regulating the cell cycle by cyclins and cdk’s Differentiate between DNA replication on the leading and lagging strand. Describe how the Hershey and Chase experiment contributed to the discovery of DNA.

5. Haplopappus is an annual flowering plant that grows in deserts. It has a 2n number of only four. – This means that the cells in the vegetative parts of the plant that are not undergoing mitosis have how many DNA molecules? – During metaphase of mitosis, how many DNA molecules would be in the nucleus? What phase of the cell cycle are most body cells in? List and describe the external environmental factors that influence the cell cycle.

6. A horticulturalist breeds orchids, trying to obtain a plant with a unique combination of desirable traits. After many years she finally succeeds. To produce more plants like this one, should she cross-breed it with another plant or clone it? Why? Each sperm cell of a pea plant contains seven chromosomes. What are the haploid and diploid numbers of this plant?

7. Identify the stage and type of cell division you see on the picture. Determine the haploid and diploid number of this cell. Label the chromosomes (duplicated or not duplicated ?), centromere, nonsister chromatids, homologous chromosomes, chiasmata, sister chromatids, spindle fibers, centrioles