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41 Cards in this Set
- Front
- Back
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2 Reasons why cell diveide rather than grow indefinatly?
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-there are more demands on DNA
-problems with moving nutrients around |
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What determines the rate at which food and oxygen are used up
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-Cells volume
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Does cell volume grown more rapidley than suface area?
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yes
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Cell Division
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process by whcih cells divide and reproduce
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How does cell division solve the problem of increading in size?
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reduces cell volume
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How can you obtian a cells ratio of surface area to volume?
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Dive surface area by volume
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Chromosomes are not visibel in most cells except during cell division
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true
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When chromosomes become visible at the beginning of cell dvisiion, whjat does each chromosome consist of>
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Two identical sister chromatin
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Each pair of chromatids is attached at an area called the
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centro mere
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The period of growth in between cell divsion is called
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interphase
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What is the cell cycle?
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the series of events in which cells go through-life of a cell
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The division of the cell nucleus during the M phase of the cell cycle is called
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mitosis
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Interphase is divided into what three phases?
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G-1 S and G-2
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What happens during the G-1 phase?
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cells do most of their growing
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What happens during the S phase
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chromosomes are replicated
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What are the four phases of Mitosis?
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prophase, metaphase, anapahase, telaphase
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Centrioles
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two tiny structures located int eh cytoplasm near the nuclear envelope at the beginning of prophase
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What is the spindle
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a fan like micro tubular structure to help seperate chromosomes
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Prophase
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The chromosomes become visible and the centriols take up positions on opposite sides of the nucleus
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Metaphase
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The chromosomes line up across the center of the cell
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Anaphase
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The chromosomes move until they form two groupls near the poles of the spindle
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Telophase
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The nucleolus becomes visible in each doaughter nucleus and a nuclear envelope re-forms around each cluster of chromosomes
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Cytokinesis
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division of cytoplasm
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How does cytokinesis occur in most animal cells?
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pinching off of two big cells
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What forms midway between the divided nuclus during cytokinesis in plant cells?
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Cell plate
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Chromatid
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one of two identical "sister" parts of a duplicated chromosome
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Chromatin
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granular material visible within the nucleus, consists of DNA tightly coiled around proteins
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Chromosome
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threadlike structure within the nucleus containing the genetic information that is passed form one generation of cells to the next
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Cyclins
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regulate the timing of the cell cycle in eukaryotic cells
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Centrioles
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two tiny structures loacted in
the cytoplasm near the nuclear envelope |
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How do prokaryotic cells reproduce?
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Fission
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What are cells that result from cell division called?
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daughter cells
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Plant cell compared with an animal cell
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Plant Cell- no centrioles and cell plates cut cells in half
Animal Cell- furrow divides cell in half |
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Internal Regulators
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proteins that control events with in cell to ensure correct sequence
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External Regulators
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proteins respond to events outside the cell-speed up slow down cell cycles- growth regulators
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Gene p53
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halts cell cycle until chromosomes are properly replicated-defect in gene is cancer
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G-0 phase
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just prior to the S phase- time out phase- cells divide which course to fallow
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Somatic Cell
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body cell
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What dictates how many times a cell divides
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telomeres-
exception is sperm, cancer, egg, bone marrow |
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Chemical Factors that influence cell growth
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cyclins, hormones, local growth factor
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Telomerase
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an enzyme that keeps telomers long in same cell
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