Basic Principles of Biotechnology MCQs

Question 1

Which of the following is a prime example of a ribonucleoprotein enzyme, the catalytic activity of which (under non-physiological conditions), resides solely in its RNA component

Accepted Answer

RNase P

Answer

Reverse transcriptase

Answer

Cytochrome c

Answer

Bacterial RNA polymerase

Question 2

Main functions of baffles in a bioreactor are P. To prevent a vortex. Q. To increase aeration. R. To reduce interfacial area of oxygen transfer. S. To reduce aeration rate.

Accepted Answer

P, Q

Answer

Q, R

Answer

R, S

Answer

P, S

Question 3

All the following may be methods for the inhibition of microbial growth by antibiotics except

Accepted Answer

Antibiotics prevent the release of energy from ATP

Answer

Antibiotics disrupt cell wall synthesis

Answer

Antibiotics interfere with cell membrane function

Answer

Antibiotics inhibit the synthesis of protein

Question 4

A feature common to almost all transmembrane proteins is

Accepted Answer

An alpha-helical region of about 20 to 25 hydrophobic amino acids

Answer

A phosphorylated exterior domain

Answer

A structure consisting almost exclusively of beta-sheets

Answer

An amino acid sequence rich in acidic residues

Question 5

The distribution of transmembrane protein in the palne of a cell membrane can best be visualized by which of the following:

Accepted Answer

Freeze-fracture electron microscopy

Answer

Thin-section electron microscopy

Answer

Scanning electron microscopy

Answer

SDS gel electrophoresis

Question 6

Broker, Chow, Roberts and P. Sharp hybridized mRNA from adenovirus to denatured adenovirus DNA and examined the resultant duplex molecules by electron microscopy. Which of the following did they observe?

Accepted Answer

On one strand there were looped out regions of single-stranded DNA

Answer

mRNA and DNA formed a continuous duplex throughout the length of the RNA

Answer

mRNA and DNA formed a continuous duplex throughout the length of DNA

Answer

On one strand there were looped out regions of single-stranded RNA

Question 7

If a mutation occurred in the phosphorylation site in the CTD domain of RNA polymerase II, which of the following outcomes would be observed?

Accepted Answer

Transcription of mRNA would not occur

Answer

Transcription of tRNA would occur normally

Answer

Transcription of precursor rRNA would not occur

Answer

All of the above

Question 8

A microorganism when viewed under a compound microscope with objective of 40X and eye piece of 10X magnification measured 400μ in length. The same microorganism when viewed under a dissecting microscope with 10X lens, would measure

Accepted Answer

10μ

Answer

100μ

Answer

40μ

Answer

400μ

Question 9

Which of the following technique is used to inactivate a gene by altering the DNA encoding it?

Accepted Answer

Homologous recombination

Answer

Antisense nucleic acid blocks

Answer

Antibody microinjection

Answer

Introduction of dominant inhibitory mutants