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22 Cards in this Set
- Front
- Back
prokaryote |
microscopic single-celled organism which has neither a distinct nucleus with a membrane nor other specialised organelles, including bacteria |
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What makes prokaryotes simpler than eukaryotes? |
prokaryotes have no distinct nucleus and no specialised organelles |
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What is the cell wall of bacteria made of? |
peptidoglycan |
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How big are the ribosomes of bacteria? |
small |
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What kind of DNA do bacteria cells have? |
circular |
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Define eukaryote. |
organism consisting of a cell or cells in which the genetic material is DNA in the from of chromosomes contained in a distinct nucleus |
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How large are the ribosomes of animal cells? |
larger than bacteria cells |
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Name 2 membrane-bound organelles involved in the processing of proteins in animal cells. |
endoplasmic reticulum golgi |
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What are the 3 extra organelles that plant cells have compared to animal cells? |
cell wall, large vacuole, chloroplasts |
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length of specimen = |
length of image / magnification |
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What is the magnification of a light microscope based on? |
the combination of the magnification of the objective lens and the eye piece (magnifications multiplied together) |
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1cm =__ mm |
10 mm |
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1mm =__ µm |
1000 µm |
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1 µm =__ nm |
1000nm |
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Define resolution. |
a measure of how easy it is to distinguish between two points that are close together |
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Define diffusion |
the passive overall movement of particles from an area of high concentration to an area of low concentration |
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Why is facilitated diffusion necessary for some molecules? |
molecules too large to diffuse across cell membranes need to be helped |
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How are large molecules diffused across cell membranes? |
they are helped by carrier proteins which change shape to pass molecules through cell membranes |
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Does facilitated diffusion require energy? |
no |
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How is facilitated diffusion specific? |
each molecule has its own carrier proteins that allows it through the cell membrane |
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Define osmosis |
diffusion of water molecules from high to low concentration across a partially permeable membrane |
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Define active transport |
using energy to transport substances from low to high concentration |