Lysozyme that is present in perspiration, saliva and tears, destroys:
(a) certain fungi
(b) certain types of bacteria
(c) all viruses
(d) most virus-infected cells
Select the wrong statement from the following:
(a) both chloroplasts and mitochondria contain an inner and an outer membrane
(b) both chloroplasts and mitochondria have an internal compartment, the thylakoid space bounded by the thylakoid membrane
(c) both chloroplasts and mitochondria contain DNA
(d) the chloroplasts are generally much larger than mitochondria
Which of the following statements regarding mitochondrial membrane is not correct?
(a) The outer membrane is permeable to all kinds of molecules
(b) The enzymes of the electron transfer chain are embedded in the outer membrane
(c) The inner membrane is highly convoluted forming a series of infoldings
(d) The outer membrane resembles a sieve
A major breakthrough in the studies of cells came with the development of electron microscope. This is because :
(a) the resolution power of the electron microscope is much higher than that of the light microscope
(b) the resolving power of the electron microscope is 200 - 350 nm as compared to 0.1 - 0.2 nm for the light microscope
(c) electron beam can pass through thick materials, whereas light microscopy requires thin sections
(d) 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
Which of the following statements regarding cilia is not correct ?
(a) The organized beating of cilia is controlled by fluxes of Ca2+ across the membrane
(b) Cilia are hair-like cellular appendages
(c) Microtubules of cilia are composed of tubulin
(d) Cilia contain an outer ring of nine doublet microtubules surrounding two single microtubules
Which one of the following phenomena is commonly referred as 'cell drinking?
If a chloroplast of plant is isolated and studied in a test tube the investigation is described as
(a) in vivo
(b) in vitro
(c) in situ
(d) none of these.
An organelle present in plant cells but absent from those of animals is
(d) Both a and c
Primary cell wall consists of a loose network of cellulose microfibrils impregnated with a matrix of
(a) glycoprotein and flavoprotein
(b) hemicellulose and flavoprotein
(c) hemicellulose and pectin
(d) flavoprotein and pectin.