The Process of Cell Division Key

Name Key Class Dato Report 38 Save University, Acadia University Course: BIOL 2663 | Marine Biology Academic year: 2024 Views: 131 Pages: 4 Author: pigman pig Description Show description 10.2 The Process of Cell Division Lesson Objectives Describe the role of chromosomes in cell division. Name the main events of the cell cycle. Describe what happens during the four phases of mitosis, Describe the process of cytokinesis. Lesson Summary Chromosomes Packages of DNA called chromosomes hold a cell's genetic information. Prokaryotic chromosomes consist of a single, circular strand of DNA. Eukaryotic chromosomes are highly organized structures. The DNA winds around histone proteins, forming chromatia. Chromosomes make the precise separation of DNA possible during cell division. The Cell Cycle The cell eyele is the series of events in the growth and division of a cell. In the prokaryotic cell cycle, the cell grows, duplicates its DNA, and divides by pinching in the cell membrane. The eukaryotic cell cycle has four stages (the first three of which are referred to as interphase): In the G phase, the cell grows. In the S phase, the cell replicates its DNA. In the Go phase, the cell produces organelles and materials for division. In the M phase, the cell divides in two stages mitosis, the division of the nucleus, and cytokinesis, the division of the cytoplasm. Mitosis The division of the nucleus, mitosis, occurs in four stages: Prophase: a cell's genetic material condenses, a spindle starts to form, and the nuclear envelope breaks down. Metaphase: the duplicated chromosomes line up and spindle fibers connect to the centromeres Anaphase: sister ehromatids separate and move toward the centrioles, Telophase: the chromosomes begin to unwind and a nuclear envelope reforms. Cytokinesis Division of the cytoplasm differs in plant cells and animal cells. In animal cells, the cell membrane draws in and pinches off. In plant cells, a cell plate forms, followed by a new cell membrane, and finally a new cell wall forms. Nama Class Date Chromosomes For Questions 1-5, complete each statement by writing the correct word or words. 1. Cells carry genetic information in molecules of DNA called chromosomes 2. Chromosomes condense and become visible during prophase 3. To make it more compact, DNA wrapped is around protein molecules. 4. Spindle fibe precisely separate the DNA during cell division. 5. Human cells have 40 chromosomes. The Cell Cycle 6. What are three reasons why cells divide? Reproduction; Growth and development; and tissue renewal & repair 7. What happens during each of the three parts of interphase? G-growth, call functioning, S-DNA replication; G₂- preparation for mitosis 8. Complete the cell cycle diagram by writing the correct name of a phase on each line. G M interphase S G 9. In eukaryotic cells, what happens in the G: phase that differs from the G₂ phase? Growth 10. In eukaryotic cells, what are the two main stages of cell division? Mitosis and cytokinesis Mitosis Sisten Chroma 11. During prophase, when/coll chromosomes become visible, what are the duplicated strands of DNA called? Chromosome 12. How can a cell with 46 chromosomes divide, yet have two daughter cells that each have 46 chromosomes? When the sister chromatids separate during anaphase, each becomes its own chromosome. For Questions 13-16, match the description of the event with the phase of mitosis in which it occurs. Each phase may be used more than once. Event D 13. The chromosomes separate and begin to move to opposite sides of the cell. B 14. The chromosomes become visible. The centrioles take up positions on opposite sides of the nucleus. A 15. A nuclear envelope re-forms around each cluster of chromosomes. The nucleolus becomes visible in each daughter nucleus. 16. The chromosomes line up across the center of the cell. Phase of Mitosis A. Telophase B. Prophase C. Metaphase D. Anaphase 17 THINK VISUALLY The four circles below represent the nucleus of a cell going through mitosis. Draw four chromosomes as they go through each phase. Label each phase and describe what is happening to the DNA. Xx Xx Chromosomes Condensing Chromosomes the up at all equator 3 Chromosomes sput nach chro artid is now a Chromosome, bring Pulled to opposite end of cell as its formur sisth chromatic Chroreesomes relax (opposit of condense) Prophase Metaphase Anaphase Telophase 148.