Questions without answers in Microbiology

To determine the viable cell count of a bacterial culture, you have plated $50 ~\mu \mathrm{~L}$ of a $100$ -fold diluted sample of the culture on a nutrient agar plate a...

Match the type of bacteria in Group I with their respective growth properties in Group II.Group IGroup IIP. Halophile1. Grows optimally between $20^{\circ} \mathrm{C}$ an...

Match the virus in Group I with the type of genome it contains in Group II.Group IGroup IIP. T4 bacteriophage1. dsRNAQ. SARS-CoV-22. ssDNAR. Pseudomonas phage $\phi 6$3. ...

Which of the following statement(s) is(are) TRUE about fluoroquinolone drugs?They contain quinolone ring(s)They inhibit RNA polymeraseThey bind to bacterial topoisomerase...

In binomial nomenclature, the name of a bacterial strain is written with the first letter of __________ word(s) being capitalized.firstsecondneitherfirst and second

Which of the following is(are) $\text{COMMON}$ feature(s) for both aerobic and anaerobic bacterial cultures?Glycolysis$\text{NAD}^{+}$ is the oxidising agentOxidative pho...

Emerging viruses such as $\text{SARS-Co V2}$ cause epidemics. Which of the following process(es) contribute to the rise of such viruses?Mutation of existing virusJumping ...

A bacterial strain is grown in nutrient medium at $37^{\circ}\text{C}$ under aerobic conditions. The medium is inoculated with $10^{2}$ cells from a seed culture. If the ...

Coronavirus genome consists ofdouble-stranded $\text{DNA}$double-stranded $\text{RNA}$negative-sense single-stranded $\text{RNA}$positive-sense single-stranded $\text{RNA...

Which one of the following is $\text{CORRECT}$ about microbial growth medium?Luria-Bertani broth is a synthetic mediumNutrient broth is a defined mediumSabouraud dextrose...

Decimal reduction time of a bacterial strain is $20 \textit{ min}$. Specific death rate constant in $\textit{min}^{-1}$ (rounded off to two decimal places) is ___________

Which of the following antimicrobial agent(s) is/are growth factor analog(s)?$5$-FluorouracilIsoniazidSulfanilamideTetracycline

A $0.1 \textit{ mL}$ aliquot of a bacteriophage stock having a concentration of $4 \times 10^9 \textit{ phages mL}^{-1}$ is added to $0.5 \textit{ mL}$ of $\textit{E. col...

Carl Woese used the gene sequence of which one of the following for phylogenetic taxonomy of prokaryotes?A ribosomal $RNA$ of large ribosomal subunitA ribosomal $RNA$ of...

A list of pathogens $(Group\; I)$ and a list of anti-microbial agents $(Group\; II)$ used to treat their infections are given below. Match the pathogens with the correspo...

Tetracycline inhibits theinteraction between $tRNA$ and $mRNA$translocation of $mRNA$ through ribosomepeptidyl transferase activitybinding of amino-acyl $tRNA$ to ribosom...

Match the human diseases in $Group\; I$ with the causative agents in $Group\; II$.$$\begin{array}&&\textbf{Group I} & \textbf{Group II} \\ &\text{P. Amoebiasis} & \text{...

Which of the following processes can increase genetic diversity of bacteria in nature?ConjugationTransformationTransductionTransfection$P$ only$P$ and $Q$ only$P, Q$ and ...

Bacteria with two or more flagella at one or both ends are calledamphitrichousperitrichouslophotrichousatrichous

Which family of viruses has single stranded DNA?HerpesviridaePoxviridaeRetroviridaeParvoviridae

Which of the following are TRUE for Treponema pallidum?It is the causative agent of syphilisIt is a spirocheteIt is a non-motile bacteriumIt is generally susceptible to p...

Which combination of the following statements is CORRECT for cyanobacteria?They can perform oxygenic photosynthesisUsually filamentous forms are involved in nitrogen fixa...

Which of the following events occur during the stationary phase of bacterial growth?Rise in cell number stopsSpore formation in some Gram-positive bacteria such as Bacill...

Which one of the following organisms is an indicator of fecal contamination?$\textit{Escherichia coli}$$\textit{Streptococcus lactis}$$\textit{Bacillus subtilis}$$\textit...

Assertion [a]: Gram negative bacteria show staining with saffranin.Reason [r]: Gram negative bacteria have an outer membrane with lipopolysaccharides.Both [a] and [r] are...

A bacterium has a genome of size $6$ million base pairs. If the average rate of DNA synthesis is $1000$ base pairs/second, the time taken (in minutes) for replication of ...

One hunderd E.coli cells are each infected by a single $\lambda$ phage particle. The ratio of the number of phage particles committing to lysogeny to those committing to ...

Which one of the following organisms is used for the determination of phenol coefficient of a disinfectant?Salmonella typhiEscherichia coliCandida albicansBacillus psychr...

Which one of the following is NOT a product of denitrification in Pseuadomonas?$N_2$$N_2O$$NO_2^-$$NH_4^+$

Match the antibiotics in $\text{Group I}$ with their modes of action in $\text{Group II}$.$\begin{array}{|l|l|l|l|} \hline & \text{Group I} && \text{Group II} \\ \hline ...

Samples of bacterial culture taken at $5$ PM and then the next day at $5$ AM were found to have $10^4$ and $10^7$ cells.mL${-1}$, respectively. Assuming that both the sam...

The most plausible explanation for a sudden increase of the respiratory quotient $(RQ)$ of a microbial culture is thatcells are dyingyield of biomass is increasingthe fer...

Gram-positive bacteria are generally resistant to complement-mediated lysis becausethick peptidoglycan layer prevents insertion of membrane attack complex into the irmer ...

A bacterium belonging to cocci group has a diameter of $2\:\mu m.$ The numerical value of the ratio of its surface area to volume (in $\mu m^{-1}$) is _______.

Which of the following essential element(s) is/are required as major supplement to enhance the bioremediation of oil spills by the resident bacteria?SulfurNitrogen and ph...

Lysine is being produced in a lab-scale reactor by a threonine auxotroph. After 2 weeks of operation it was observed that the concentration of lysine in the reactor was g...

Match the cell structures in $\text{Group I}$ with the organisms in $\text{Group II}$.$\begin{array}{|l|l|l|l|} \hline & \text{Group I} && \text{Group II} \\ \hline P. & ...

Match the commercial microbial sources in $\text{Group I}$ with the products in $\text{Group II}$.$\begin{array}{|l|l|l|l|} \hline & \text{Group I} & & \text{Group II} \...

A bacterial culture ($200 \: \mu l$ containing $1.8 \times 10^9$ cells) was treated with an antibiotic $Z$ ($50 \: \mu g$ per $ml$) for $4$ h at $37^\circ C$. After this ...

Match the entries in $\text{Group I}$ with the methods of sterilization in $\text{Group II}$$\begin{array}{|l|l|l|l|} \hline & \textbf{Group I} && \text{Group II} \\ \h...