Chapter 10 Study guide Open Stax Biology 2e PDF

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Download Chapter 10 Study guide Open Stax Biology 2e PDF

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Chapter 10 Study Guide – OpenStax Biology 2e Reading Assignment: Read Chapter 10: For this chapter you should read all of sections 10.1 and 10.2. In section 10.3 you need to read the introduction and the section called “regulation at internal checkpoints”. Be sure you know the G1, G2, and M checkpoints. Read all of section 10.4. You can skip or skim section 10.5 (won’t be quizzed or tested on it!)

Terms to know and understand: Anaphase Cell cycle Cell cycle checkpoint Cell plate Centriole Centromere Chromatid Cleavage furrow Cytokinesis diploid G0 phase G1 phase

G2 phase gamete gene genome haploid histone homologous chromosome interphase kinetochore locus metaphase metaphase plate

mitosis mitotic spindle oncogene p53 prometaphase prophase proto-oncogene S phase Telophase Tumor Suppressor gene

Chapter Review Questions: 1. Write the following terms in order from the smallest to the largest structure (in terms of size and complexity). DNA wrapped around histones, DNA molecule/ double helix, a single chromosome, duplicated chromosome DNA molecule/double helix, DNA wrapped around histones, a single chromosome, duplicated chromosome

2. Our human body cells all have 2 copies of every chromosome. We got one copy from each of our parents. This is called diploid/haploid (select one).

3. An egg or a sperm cell is called haploid. In what way do the chromosomes of an egg or a sperm cell differ from the chromosomes of our body cells? The cells in our body contain two copies of every chromosome and is called diploid, while an egg or sperm only has a single set of chromosomes and is called haploid.

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4. In your own words, summarize what is meant by the term “the Cell cycle”. You don’t need all the details here – you will write those in the next question. The cell cycle is the cycles where a cell forms, grows, develops a normal function and where it divides.

5. Now, draw or fully describe the detailed steps of the cell cycle. Your answer should include all of the listed terms AND, for each term, you should indicate what is occurring during that part of the cell cycle. •

Terms to include: Interphase, G1, G2, G0, S, Mitotic phase, Mitois, Cytokinesis. The cell cycle consists of interphase and the mitotic phase. During interphase which is divided into three stages G1, G2, G0, and S, the cell grows and the nuclear DNA is duplicated. Interphase is followed by the mitotic phase. During the mitotic phase which is in two parts mitosis and cytokinesis , the duplicated chromosomes are segregated and distributed into daughter nuclei. The cytoplasm is usually divided as well, resulting in two daughter cells.

6. During the S phase (a part of interphase) the DNA is replicated. We will learn about DNA replication in a later chapter. For now you need to know that each of the 46 individual chromosomes that existed in the human cell are copied and the copy becomes attached to the original chromosome at the centromere (centromeric region) of the chromosome. Whenever you see a drawing of chromosomes that looks like a long “X” shape (see figure 10.7 for an example) you are seeing ONE chromosome with is exact copy attached. •

This chromosome with its copy attached is called a pair of chromatids _________________ .

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How many pairs of sister chromatids would you find in a human cell right after S-phase has completed? _46____

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Draw a pair of sister chromatids and label the centromere, kinetochore, and mitotic spindle. *attached document* 2!

7. Describe the events that are occurring during each stage of mitosis AND draw a sketch showing what is happening to the cell and its chromosomes during each phase. • Prophase: During prophase the nuclear envelope breaks up into small vesicles, and the microtubules begin to form and push the centrosomes to opposite ends of the cell

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Prometaphase: During prometaphase chromosomes become more condensed and easy to see, and microtubules attach to the kinetochores of each sister chromatid.

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Metaphase: During metaphase the mircortubules that are attached to the kinetochores spindle lengthen and shorten in order to pull the pairs of sister chromatids and line them up along the metaphase plate and by the end of metaphase the chromosomes are lined up end to end along the cells equator

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Anaphase: During anaphase the sister chromatids are separated and the motor proteins in kinetochores pull sister chromatids apart using the microtubules and the chromatids are rapidly pulled to opposite centrosomes on either side of the cell.

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Telophase: During telophase the spindle microtubules break apart and the nuclear membrane forms around two groups of chromosomes to form 2 new nuclei.

8. Cytokinesis is the second part of the mitotic phase (mitosis was the first part). Describe what happens in an animal cell during cytokinesis. 3!

Durning cytokinesis in animal cells the equator of the cell is pulled inward forming a cleavage furrow, and the furrow deepens until the membrane is cleaved in two and two separate cells are now formed ! 9. How is cytokinesis in a plant cell different then in an animal cell? Describe or draw this. During cytokinesis in plant cells the stiff cell walls form the cleavage furrow instead of the cell being pulled inward that formed the cleavage furrow in animal cells. 10. Review the three cell checkpoints of the cell cycle. Why is it important that the cell has these checkpoints (what would be the result if there were no checkpoints?!). The three checkpoints are G1 (interphase), G2 (interphase), and M (metaphase). If there were no checkpoints that our DNA could be very corrupt and could be prone to cancer.

11. List and summarize the three checkpoints of the cell cycle. During G1 the DNA is checked to make sure it’s intact and ready to be replicated and if the cell is prepared to proceed to division, then during G2 the DNA is checked to see if it’s been properly duplicated and finally during M the chromosomes are checked to see if there attached to the spindle and that there lined up properly.

12. What is the basic mechanism that is the cause of all types of cancer? (see introduction paragraph to section 10.4). A mutation in a gene that is not stopped by normal controls can become a cancer cell

13. Mutated p53 genes have been found in more than half of all human tumor cells. Re-read the section about p53 tumor suppressor genes and then describe why a normally functioning p53 gene helps prevent cancer cells from developing. A p53 gene can help prevent cancer cells from developing because its a tumor suppressor gene and it prevents cell division from occurring, and if a damage is detected the p53 gene triggers a repair mechanism. 4!

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