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Page 1

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Cells, Exchange and Transport
(a) state the resolution and magnification that can be achieved by a light microscope, a transmission electron
microscope and a scanning electron microscope;
Resolution Magnification
Light microscope 200nm x1,500
Transmission Electron Microscope 0.1nm x500,000
Scanning Electron Microscope 0.1nm X100,000

(b) explain the difference between magnification…

Page 2

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Cells, Exchange and Transport
(f) outline the functions of the structures listed in (e);
Houses all of the cell's genetic material in the form of DNA, which contains the instructions for protein synthesis.
Makes ribosomes and RNA which pass into the cytoplasm and are used in protein synthesis…

Page 3

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Cells, Exchange and Transport
(h) compare and contrast, with the aid of diagrams and electron micrographs, the structure of prokaryotic cells and
eukaryotic cells;
Prokaryotic cells do not have a nucleus. They are bacteria and are much smaller than Eukaryotic cells.
They have:
· One membrane
· No membrane-bound organelles…

Page 4

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Cells, Exchange and Transport
Cell Membranes
(a) outline the roles of membranes within cells and at the surface of cells;
· Separate cell contents from the outside environment
· Separate cell components from the outside environment
· Cell recognition and signalling
· Holding the components of some metabolic pathways in…

Page 5

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Cells, Exchange and Transport

ALM June 10

Page 6

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Cells, Exchange and Transport
Cell Division, Cell Diversity and Cellular Organisation
(a) state that mitosis occupies only a small percentage of the cell cycle and that the remaining percentage includes
the copying and checking of genetic information;
(b) describe, with the aid of diagrams and photographs, the main stages of…

Page 7

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Cells, Exchange and Transport
(i) describe and explain, with the aid of diagrams and photographs, how cells of multicellular organisms are specialised
for particular functions, with reference to
erythrocytes (red blood cells),
Biconclave disc shape to maximise surface area
No nucleus = more room for haemoglobin
Flexible shape to…

Page 8

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Cells, Exchange and Transport
Ciliated epithelial tissue
· Column- shaped
· Exposed surface covered with cilia
· Move in synchronised waves
· Found on surface of tubes (e.g. bronchi, oviduct)
· Waft mucus in lungs, egg in oviduct
· Composed of xylem vessel cells and parenchyma cells
· Parenchyma…

Page 9

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Cells, Exchange and Transport
Exchange Surfaces and Breathing
(a) explain, in terms of surface area:volume ratio, why multicellular organisms need specialised exchange surfaces and
single-celled organisms do not;
Organisms need to absorb certain substances, (e.g. oxygen, glucose, proteins, fats, water and minerals) from
the surrounding environment and remove waste products…

Page 10

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Cells, Exchange and Transport
(e) describe the functions of
Holds the trachea and bronchi open
Prevents collapse when the air pressure is low during inhalation
Move in a synchronised pattern to waft mucus up the airway to the back of the throat. Once there, the mucus


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