Question

The inner membrane of mitochondria bears folding/finger like projections, these
A. Increase surface area
B. Increase thickness of mitochondria
C. Keep all the substance away
D. Increase protein oxidation

Answer 1

Mitochondria are the membrane bound organelles which have two membranes i.e., inner and outer membranes. Inner membrane has finger-like projects which function to accommodate more area for ATP generation.

Complete answer:
First of all, you should know what mitochondria is. Mitochondria are membrane bound organelles which generate chemical energy which is then stored in the form of ATP molecules and it is also called power house of the cell since it generates energy.
There are two membranes of mitochondria- Inner membrane and Outer membrane.
Inner membrane beards finger like projections which are called cristae and these folds provide an increase in the surface area which then let mitochondria to generate more ATP molecules.
Outer membrane is smooth and this membrane acts as a selective barrier to molecules from the cytoplasm.
Let's look at options now, option A is Increase surface area. It is the correct option since the folding present on the inner membrane of mitochondria increases the surface area for it to produce more molecules of ATP. Hence, it is the correct option.
Moving to option B which is Increase the thickness of mitochondria. Due to the presence of folding, it increases surface area but not the thickness of mitochondria and therefore this option is incorrect and it gets eliminated.
Moving to option C which is Keep all the substance away. This option is also incorrect since the folding of the inner membrane does not function to keep all the substance away but to increase the surface area. Therefore this option is also incorrect and it gets eliminated.
Last option D is Increase protein oxidation. This option is also incorrect if folding of the inner membrane does not function to increase the protein oxidation but to increase the surface area. Therefore this option is also incorrect and it gets eliminated.

Thus, the correct answer is option A which is Increase the surface area.

Note: Since there are two membranes of mitochondria, the inner one has finger-like projections which functions to increase the surface area and due to its presence it helps the mitochondria in order to generate more chemical energy and this chemical energy is stored in the form of ATP molecules.