biology chapter 9 – Flashcards
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Cancer cells require many nutrients, which are supplied by blood vessels. The growth of new blood vessels to cancerous tissue is called:
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angiogenesis
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Virtually all specialized cells of multicellular organisms
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have the same amount of DNA and the same number of chromosomes as all other cells of the organism and develop from the same basic stem cells.
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If a parent cell has 48 chromosomes, how many chromosomes will each daughter cell have after mitosis and cytokinesis occurs?
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48 chromosomes
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Eukaryotic chromosomes
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may occur as chromatin, consist of both DNA and protein, contain histones responsible for packaging DNA to fit into a small space.
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The enzymes that bring about apoptosis are: called caspases.
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true
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The enzymes that bring about apoptosis are: are ordinarily held in check by inhibitors.
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true
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The enzymes that bring about apoptosis are: can be unleashed by internal or external signals.
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true
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Which is NOT true about the chromosomes of a multicellular organism?
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Each chromosome separates into two daughter chromosomes by binary fission.
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The function of mitosis is:
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asexual reproduction in some species, growth of the organism and tissue repair, and to ensure that each new cell receives a complete set of genetic information.
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The haploid (n) number of chromosomes for a human being is
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23
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Below the skin are "stem cells" that divide, with some cells continuing the stem cell line and others being pushed toward the surface to flatten and die and be sloughed off. In the bone marrow other stem cells produce erythrocytes that lose their nucleus and function for a few months in the bloodstream before they too die. Such "dead end" cells that reproduce no further
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leave the cell cycle in a G0 phase, which immediately follows telophase.
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During which stage of the cell cycle is cell growth and replication of organelles most significant?
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G1 phase
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Which stage is most associated with a cell that is unable to divide again, such as a muscle or nerve cell?
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Go phase
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In some organisms, mitosis occurs without cytokinesis. This results in:
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a multinucleated cell
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What occurs in anaphase?
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Chromosomes move to opposite poles.
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Cytokinesis in plant cells differs from this process in animal cells because
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the Golgi apparatus produces vesicles that migrate along microtubules and fuse to become a cell plate.
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Oncogenes are all of the following EXCEPT:
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tumor suppressor genes
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Which is NOT correctly associated with cancer?
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The disorganized mass of cells is encapsulated and does not invade adjacent tissue
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Generally, complex organisms do require more genes to control their synthesis and organization than do primitive organisms. However, the numbers of chromosomes vary from ants with 2, molds with 8-14, humans with 46, potatoes with 100 and the crayfish with 200! Some birds and insects have chromosomes that dwindle in size into obscurity, so it is not possible to establish a diploid number. How do you explain this situation?
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the number of genes per chromosome may vary among organisms, preventing a simple relationship between chromosome number and complexity.
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The event that signals the start of anaphase is
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division of the centromeres to separate sister chromatids.
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Viruses and chemical exposure can cause mutations in proto-oncogenes which can lead to cancer.
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true
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Which statement below best describes the difference between mitosis and cytokinesis?
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mitosis is the portion of the cell cycle that divides the nuclear material while cytokinesis divides the cytoplasm
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Which statement below lists the correct steps for binary fission?
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1. attachment of chromosome to the plasma membrane, 2. enlargement of cell volume, 3. DNA replication occurs, 4. a new cell wall and plasma membrane divide the cell in half, 5. cell elongates and chromosomes are pulled apart
