Which one of the following is correct for the transmembrane proteins in lipid bilayer of plasma membrane?
(1) They are absent in animal cells.
(2) They act as channel proteins.
(3) They are absent in plant cells.
(4) They are only externally located
Identify the accurate explanation of mesosome.
(1) a specialised structure of prokaryotic cell formed by extension of plasma membrane into the cytoplasm
(2) the middle layer of the prokaryotic cell wall
(3) the organelle of eukaryotic cell which helps in lipid synthesis
(4) the middle layer of eukaryotic cell wall.
Mitochondria and chloroplast are believed to be bacterial endosymbiont because
I. they have self nucleic acid i.e., circular ds, DNA and RNAs
II. 70s ribosomes
III. their membrane resembles that of bacteria
IV. ETS and ATP forming machinery is present.
(1) I and II
(2) I, II and III
(3) All of these
(4) I and IV
If a biochemical analysis of mitochondria has to be done, the best procedure would be
(1) select cells which have a larger number of mitochondria
(2) plasmolyse the cell and filter out the mixture and take the debris
(3) grind the cells and filter out the mixture and take the debris
(4) subject the cell to cell fractionation (centrifuge) and obtain mitochondria
Which one of the following structure is an organelle within an organelle?
SER and RER can be distinguished with its presence in
(1) protein synthesising cells
(2) protein and fat synthesising cells
(3) carbohydrates and fat synthesising cells
(4) lipid and protein synthesising cells
Fluid mosaic model of plasma membrane was given by
(2) Robert Hooke
(3) Singer and Nicholson
(4) Gorter and Grendel
The percentage of cell surface that is impenetrable for ions is
(1) 1 %
(2) 99.9 %
(3) 90 %
(4) 73 %
The property of semipermeability belongs to
(1) cell wall
(2) plasma membrane
(3) mitochondria only
(4) None of the above
Microtubules are absent in
(3) spindle fibres