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31 Cards in this Set
- Front
- Back
How does a prokaryotic cell divide?
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Binary fission
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How many replication origins are there in the prokaryotic DNA loop?
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One
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In which direction does replication go from the prokaryotic replication origin?
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Both directions
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All eukaryotic cells store genetic information in __________.
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Chromosomes (most have between 10 and 50)
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How many chromosomes do humans have?
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Forty-six (Twenty-three pairs)
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Which tends to have the most chromosomes: fungi, insects, animals or plants?
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Plants (The Adder's Tongue Fern has 1,262 chromosomes)
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Chromosomes are composed of _________, a DNA-protein complex.
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Chromatin (40% DNA, 60% Protein)
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What is the difference between heterochromatin and euchromatin?
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Heterochromatin is not expressed. Euchromatin is.
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Every 200 nucleotides, the DNA in a chromosome coils around a histone protein forming a ____________.
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Nucleosome
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What is a karyotype?
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An Individual's Set of Chromosomes
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What is a diploid cell? What is a haploid cell?
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A diploid cell is a cell with two copies of each chromosome (one from each parent). A haploid cell is a cell containing only one copy of each chromosome (example: gametes).
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What are homologous chromosomes?
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The two corresponding copies of the same chromosome present in a diploid cell.
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The sister chromatids in mitosis are joined by a ___________.
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Centromere
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What are the 5 phases of the cell cycle and what occurs in them?
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G1(primary growth), S(genome replication), G2(secondary growth), M(mitosis), C(cytokinesis)
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What are G1, S, and G2 collectively called?
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Interphase
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What is the kinetochore?
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The protein disk in the centromere where microtubules attach.
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What are the stages of Mitosis?
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Prophase, Metaphase, Anaphase, Telophase
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What happens in Prophase?
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The spindle apparatus is assembled, the microtubules attach to the kinetochores, and the nuclear envelope breaks apart.
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What happens in Metaphase?
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The chromosomes align themselves in the cell's center. This forms the metaphase plate.
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What happens in Anaphase?
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The chromatids are pulled toward the poles.
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What happens in Telophase?
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The spindle structure breaks down and a new nuclear envelope forms around the groups of chromatids.
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What is cytokinesis?
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The cleavage of the cell into two.
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How does it occur differently in animals, plants, fungi, and protists?
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In animals, a belt of actin filaments pinches the cell into two. In plants, a cell plate forms, forming two new cells. In fungi and protists, mitosis occurs in the nucleus.
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How is cell division controlled? What two parts of the cell cycle are irreversible?
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Checkpoints. Genetic replication and chromatid separation.
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What are the three cell checkpoints?
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G1/S (primary division decision point), G2M (commitment to mitosis), Spindle Checkpoint (decides whether mitosis was accurate enough to justify division)
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What signal do cells receive to cause them to grow?
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Growth factors
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What does gene p53 have to do with cancer?
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It is the gene that would normally delay cell division if damaged DNA is detected. Absent in many cancer cells.
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What are oncogenes?
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Genes that can create a cancerous cell if introduced to a normal cell.
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What are proto-oncogenes?
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Natural genes that can become oncogenes when mutated.
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What are tumor-suppressor genes?
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Genes that normally inhibit division of a cell. Recessive to proto-oncogenes.
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Who made these flashcards?
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Robert Fromm
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