Biological Sciences Interview Preparation Guide Download PDF
Biological Sciences frequently Asked Questions by expert members with experience in Biological Sciences. So get preparation for the Biological Sciences job interview
12 Biological Sciences Questions and Answers:
1 :: What is the difference between Gram positive & Gram negative bacteria based on its cell contents?
main difference is the peptidoglycan layey present in gram positive and absent in gram negetive.This is the reason y most drugs designed to lyse the cell wall of bacteria do not show effect on gram negetive bacteria
2 :: What percentage of agarose is required to load 2kb dna?
it is 2 percent agarose concentration used for 2 kb DNA
3 :: Explain apoptosis?
The programmed death of a cell. This type of cell death
occurs by fragmentation of membranes that are then
eliminated.
Cellular suicide or programmed cell death. HIV may induce
apoptosis in both infected and uninfected immune system
cells. Normally when CD4 cells mature in the thymus gland,
a small proportion of these cells are unable to distinguish
self from nonself. Because these cells would otherwise
attack the body's own tissues, they receive a biochemical
signal from other cells that results in apoptosis
occurs by fragmentation of membranes that are then
eliminated.
Cellular suicide or programmed cell death. HIV may induce
apoptosis in both infected and uninfected immune system
cells. Normally when CD4 cells mature in the thymus gland,
a small proportion of these cells are unable to distinguish
self from nonself. Because these cells would otherwise
attack the body's own tissues, they receive a biochemical
signal from other cells that results in apoptosis
4 :: what are Therapeutic proteins?
proteins which can be used for therapeutic purposes
6 :: How does every cell(prokariots and Eukariots) know, this is the time of divison?
external factors
7 :: Why does separation not occurs in stacking gel in gel electrophoresis and why does separation done in separating gel?
Stacking gel has a much larger pore size,and is merely used for stacking (arranging one over other) the samples so that they can be resolved in the separating gel easily. Since the separating gel has an optimal pore size so the samples separate by molecular sieving effect of the resolving gel which is absent in case of Stacking gel.
9 :: What is the difference between food infection and food?
Food infection- when the disease causing pathogenic organism are trasmitted via food it is called food infection.
Food poisioning- the toxin produced by cetain microorganism in food which leads to some undesirable change is called food poisoning.
Food poisioning- the toxin produced by cetain microorganism in food which leads to some undesirable change is called food poisoning.
10 :: What is the ph range of most bacteria and most fungai?
Bacteria generally require ph neutral or slightly alkaline i e for 7-8
fungai including both yeast and mould need acidic ph for their growth ph range for 4-6
fungai including both yeast and mould need acidic ph for their growth ph range for 4-6