Cell : The Unit Of Life
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A complex of ribosomes attached to a single strand of RNA is known as
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Polymer
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Polypeptide
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Okazaki's fragment
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Polysome
D.
Polysome
A chain of ribosomes attaches to a single mRNA is called polysome or polyribosomes.
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A major breakthrough in the studies of cells came with the development of electron microscope. This is because
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the resolution power of the electron microscope is much higher than that of the light microscope
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the resolving power of the electron microscope is 200 – 350 nm as compared to 0.1 – 0.2 nm for the light microscope
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electron beam can pass through thick materials, whereas light microscopy requires thin sections
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the electron microscope is more powerful than the light microscope as it uses a beam of electrons which has wavelength much longer than that of photons
A.
the resolution power of the electron microscope is much higher than that of the light microscope
A major break through in the studies of cell came with the development of electron microscope because the resolution power of the electron microscope is much higher than that of the light microscope.
As an average the resolving power of a light microscope is 
while of electron microscope, is 
though theoretically, it is 
. The magnification range of light microscope is 2000 - 4000 while of electron microscope is 1,00,000 - 3,00,000.
A major site for synthesis of lipids is
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RER
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SER
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symplast
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nucleoplasm
B.
SER
The Smooth Endoplasmic Reticulum (SER) is the major site for synthesis of lipids. RER is actively involved in protein synthesis and secretion. Nucleoplasm is the site for active ribosomal RNA synthesis. Symplast is the system of interconnected protoplast through, which water movement occurs.
A phosphoglyceride is always made up of
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only a saturated fatty acid esterified to a glycerol molecule to which a phosphate group is also attached
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only an unsaturated fatty acid esterified to glycerol molecule to which a phosphate group is also attached
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a saturated or unsaturated fatty acid esterified to a glycerol molecule to which a phosphate group is also attached
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a saturated or unsaturated fatty acid esterified to a phosphate group, which is also attached to a glycerol molecule
C.
a saturated or unsaturated fatty acid esterified to a glycerol molecule to which a phosphate group is also attached
A fat is formed of two kinds of smaller molecules, i.e., glycerol and fatty acids. In making a fat three fatty acid molecules each join to glycerol by an ester linkage. A fatty acid has a long carbon skeleton, usually 16 or 18 carbon atom in length. It there is no double bonds between carbon atoms composing the chain, then as many hydrogen atoms as possible are bonded to the carbon skeleton.
An elaborate network of filamentous proteinaceous structures present in the cytoplasm which helps in the maintenance of cell shape is called
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thylakoid
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endoplasmic reticulum
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plasmalemma
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cytoskeleton
D.
cytoskeleton
The cytoplasm of all eukaryotic cells is crisscrossed by a network of protein fibres that support the shape of the cell and anchor organelles to fixed locations. This network is called cytoskeleton. It consists of three types of cytoskeletal filaments namely act filaments or microfilaments (formed of globular protein actin), microtubules (formed of tubulin protein) and intermediate filaments (formed of a variety of proteins like vimentin, keratin, desmin, peripherin, lamin etc).
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