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15 Cards in this Set
- Front
- Back
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Cell Division |
cells divide because they GET TOO BIG
the volume of a cell increases FASTER than is surface area
Diffusion is too slow
DNA limitations: proteins cannot be made FAST ENOUGH |
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The Cell Cycle |
the cycle of GROWTH and DIVISION of a cell
INTERPHASE (growth) MITOSIS (division)
Cells spend most of their time doing their cell job (interphase) vs. reproducing (mitosis) |
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Interphase |
-the growth period of a cell -1st and LONGESTTTTTTT step -The cell grows and carries on metabolism (gets rid of waste, energy production, making proteins, cell repair) G1 -Chromosomes duplicated (DNA COPIED) S -Cell parts needed for division are assembled G2
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Chromosomes |
condensed clumps of CHROMATIN
appear right BEFORE cell division |
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Mitosis |
the cell undergoes division -occurs when the cell size is at its maximum -occurs in most cells of your body -4 phases -DNA is divided equally b/w 2 daughter cells (daughter cells are identical to parent EXCEPT for SIZE)
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Prophase |
1st and LONGESSSST phase of MITOSIS -chromosomes coil up and are invisible
sister chromatid - each half of a doubled chromosome -they are exact copies of each other and each is a strand of DNA connected by a centromere!
nucleus/nucleolus dissolve and are no longer visible within the cell
by late prophase, centrioles migrate toward opposite ends of the cell
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Centrioles |
structures made up of microtubules that aid in separation of sister chromatids |
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Spindle |
many microtubules branching out from the centrioles
created to PULL APART sister chromatids
MOST plants just have spindle without the help of centrioles |
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Metaphase |
chromosomes line up in the middle of the cell
centromeres become attached to spindle fibers
each centromere has 1 spindle fiber on each side
fibers come from CHROMATIDS |
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Anaphase |
sister chromatids separate
centromeres split and sister chromatids are PULLED APART -chromatids are pulled by the spindle fibers toward the centrioles at the poles of the cell
spindle fibers contract |
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Telophase |
chromatids at poles -cleavage furrow -cell begins to split its cytoplasm into 2 distinct daughter cells -chromosomes begin to unwind
nuclear envelope FORMS AGAIN around DNA(chromosomes) |
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Cytokinesis |
Cytoplasm of cell divides
STARTS: late anaphase ENDS: telophase ends
in a plant cell, a cell plate is laid down to separate the contents of the 2 cells |
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Control of the Cell Cycle |
a series of enzymes monitor a cell's progress from phase to phase
enzyme production is directed by GENES
a (disrupted cell cycle) can result in excessive cell division, or CANCER (out of control cells)
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Causes of Cancer |
environmental factors: -smoking (breast, mouth, lung, pancreatic, liver, etc.) -exposure to sunlight (UV radiation) (basal cell, malignant melanoma) -diet Genetic factors: -faculty genes -viral infections
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Skin Cancers
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Basal Cell Carcinoma
-most common type!! -affects deepest layer cells of the epidermis Squamous Cell Carcinoma -2nd most common type Malignant Melanoma - most DANGEROUS type!! -arises from pigmented areas -increased w/ young people |
