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15 Cards in this Set
- Front
- Back
What is interphase?
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Interphase = phase where growth & DNA synthesis occurs
90% of cell cycle is spent in interphase (20 hours) G0 = time when cells are at rest & not dividing (muscle & nerve cells) Interphase has 3 stages: G1 = Growth S = DNA Synthesis (copy 2 meters of DNA per cell) G2 = Protein synthesis |
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What happens at each of the mitotic phases?
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M (Mitotic) Stage = phase where nucleus & cytoplasm divide
Approximately 2 hours long Important in cell growth, development & repair Mitotic Stage (1 hour) = cell division mitosis = nuclear division cytokinesis = cytoplasm division |
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What are the products of mitosis?
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Nuclear Division and making copies of cells.
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What is a diploid number?
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2n
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What is a haploid number?
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1n
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What do the numbers mean that are involved with diploids and haploids?
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Diploid (2n) = 2 of each chromosome
Body (somatic) cells contain 2n = 46 chromosomes Haploid (1n) =1 of each chromosome Sperm and egg (gametes) have 1n = 23 chromosomes |
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What does ‘n’ refer to with diploids and haploids?
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n = numbers of chomosomes.
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What is the structure of a chromosome?
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Chromosomes = condensed or tightly coiled chromatin
Chromatid = single strand of chromosome Sister chromatids = 2 strands of genetically identical chromosomes Attached at centromere |
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What two macromolecules make up chromosomes?
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Proteins and Nucleic Acids
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How do plant and animal cell division differ?
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Mitosis: permits growth & repair
Meristematic plant tissue (root & shoot tips) retains ability to grow & divide throughout plant’s life Plants DO NOT have centrioles or asters Plants DO have centrosome & spindle Cleavage furrows and Contactile rings happen only in animal cells because of the plant cell's cell wall. |
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What is binary fission?
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Prokaryotic Cell Division = Binary Fission
Prokaryotes contain a single chromosome with only a few proteins (nucleoid) DO NOT have spindle apparatus Asexual Reproduction (yeast, Paramecium, Euglena) Binary fission: division that produces 2 daughter cells genetically identical to the parent = clones Division requires from 20 minutes (E. coli) to 24 hours to occur |
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What happens to a cell during binary fission?
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1. Attachment of the chromosome to a special site indicates tha tthis bacterium is about to divide.
2. The cell is preparing for binary fission by enlarging its cell wall, plasma membrane, and overall volume. 3. DNA replication has produced two chromosomes. Cell wall and plasma membrane begin to grow inward. 4. As the cell elongates the chromosomes are pulled apart. Cytoplasm is being distributed evenly. 5. New cell wall and plasma membrane has divided the daughter cells. |
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What is apoptosis?
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Apoptosis = Programmed Cell Death
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What happens when cells fail to undergo apoptosis?
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The cells might be considered cancerous.
Series of events that cause cell to self-destruct Capsases = enzymes that trigger apoptosis Mitosis increases apoptosis decreases the # of somatic (body) cells Occurs during development (webbed toes fingers) |
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What are some of the characteristics of cancer cells and normal cells?
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Cancer Cells:
Uncontrolled growth No Contact Inhibition Disorganized, multilayered Nondifferential cells Abnormal Nuclei Do not undergo apoptosis Normal Cells: Controlled Growth Contact Inhibition One organized layer Differential cells Normal Nuclei Undergo apoptosis Cancer = uncontrolled cell growth that results from the mutation of genes regulating the cell cycle Carcinogenesis = gradual development of cancer |