Cell-The Unit of Life
- Angstrom (Å) is equal to
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Angstrom Å = 0.0001 µm 1Å
= 10–10 m
= 10–8 cm
= 10–7 mm
= 10–4 mmCorrect Option: C
Angstrom Å = 0.0001 µm 1Å
= 10–10 m
= 10–8 cm
= 10–7 mm
= 10–4 mm
- Which is correct about cell theory in view of current status of our knowledge about cell structure
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The exceptions to cell theory are viruses which do not possess a cellular machinery. They consists of DNA or RNA core surrounded by a protein sheath and lack cellular organisation.
Correct Option: C
The exceptions to cell theory are viruses which do not possess a cellular machinery. They consists of DNA or RNA core surrounded by a protein sheath and lack cellular organisation.
- Names of Schleiden and Schwann are associated with
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Cell theory was proposed by Schleiden and Schwann (1839) according to which “All living organisms are composed of cells.” Cell theory is also known as cell principle, cell doctrine etc.
Correct Option: B
Cell theory was proposed by Schleiden and Schwann (1839) according to which “All living organisms are composed of cells.” Cell theory is also known as cell principle, cell doctrine etc.
- A student wishes to study the cell structure under a light microscope having 10X eyepice and 45X objective. He should illuminate the object by which one of the following colours of light so as to get the best possible resolution?
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Resolving power or limit of resolution is the ability of the eye to distinguish two close objects as separate. Its value is calculated by Abbe’s equation,
Lm = 0.6λ NA
where λ is the wavelength of light.
NA or numerical apperture is multiple of refractive index and sine of angle subtended by optical axis and outer ray covered by objective (sina).Correct Option: A
Resolving power or limit of resolution is the ability of the eye to distinguish two close objects as separate. Its value is calculated by Abbe’s equation,
Lm = 0.6λ NA
where λ is the wavelength of light.
NA or numerical apperture is multiple of refractive index and sine of angle subtended by optical axis and outer ray covered by objective (sina).
- A major break through in the studies of cells came with the development of electron microscope. This is because
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A major break through in cell studies came with the development of EM having great resolution power due to which we can see the ultrastructures of cell organelles.
Correct Option: D
A major break through in cell studies came with the development of EM having great resolution power due to which we can see the ultrastructures of cell organelles.
