Guided Reading on Mitosis and Cancer (Chapter 8)1.) Cells divide in both prokaryotes and eukaryotes. Explain why cell division is important in both a prokaryote and a eukaryote.Binary fission (Prokaryotes) and Mitosis, Meiosis (Eukaryotes), both must have cell division in order to replace cells and create offspring2.) As a polymer, DNA is far too long when stretched out to fit into the nucleus of a cell, yet we know that all of our DNA resides in the nucleus! How can this be?Double helix3.) Your grandmother asks you, “What is a chromosome?” How might you explain what chromosome is? A threadlike structure of nucleic acids and protein found in the nucleus of most living cells, carrying genetic information in the form of genes.a. Are chromosomes present in all your cells all of the time?4.) Compare and contrast chromosomes and sister chromatids. (Things to think about: What makes them similar? What makes them different? When would you finda cell with chromosomes? When would you find a cell with chromatids?) Every cell has chromosomes, but a cell only has chromatids if it’s going through cell division5.) What is the cell cycle? When does the cell cycle start and when does it end? Cell cycle: an ordered sequence of events that extends from the time a cell is firtst formed from a dividing parent cell until its own division into two cells6.) What are the two main stages of the cell cycle and what happens in each? Interphase (G1, S, G2) and Mitotic Phase (Mitosis and Cytokinesis)a.) At what point in the cell cycle does the cell perform its assigned function?It performs it assigned function once the cell cycle control system triggers the next step in the cycle, giving it a go-ahead signal7.) Draw a cell in each of the 5 stages of mitosis (interphase, prophase, metaphase, anaphase, telophase). Label the chromosomes, sister chomatids, centromeres, centrosomes and write a one-sentence description of what is happening at each stage.Interphase: the period of cell growth, when the cell synthesizes new molecules and organellesProphase: changes occur within both the nucleus and the cytoplasmMetaphase: the mitotic spindle is fully formed, with its poles at opposite ends of the cellAnaphase: begins with two centromeres of each chromosome come apart, separating the sister chromatidsTelophase: the cell elongation that started in anaphase continuesCytokinesis: the division of the cytoplasm8.) Describe three different ways in which you could get cells to divide.Binary fission (dividing in half), mitosis (the nucleus and its content divide and are evenly distributed, forming two daughter nuclei), meiosis (produces haploid gametes in diploid organisms)9.) What is a cell cycle check point?Cell cycle checkpoints are control mechanisms that ensure the fidelity of cell divisionin eukaryotic cells. These checkpoints verify whether the processes at each phase of the cell cycle have been accurately completed before progression into the next phase. Multiple checkpoints have been identified, though some of them are less understood than others.10.) How do growth factors promote cell division?A growth factor is a protein secreted by certain body cells that stimulates other cells to divide11.) Define the following:Tumor: a swelling of a part of the body, generally without inflammation, caused by an abnormal growth of tissue, whether benign or malignant.Benign tumor: a tumor that is not cancerousMalignant tumor: a tumor that is malignant and tends to spread to other parts of the bodyMetastasis: the development of secondary malignant growths at a distance from a primary site of cancer.Carcinomas: a cancer arising in the epithelial tissue of the skin or of the liningof the internal organs.Sarcoma: a malignant tumor of connective or other nonepithelial tissueLymphoma: cancer of the lymph
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