Recent questions tagged microbiology

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^+$

Which one of the following relations holds true for the specific growth rate $(\mu)$ of a microorganism in the death phase?$\mu=0$$\mu<0$$\mu=\mu_{\text{max}}$$0<\mu<\mu_...

Match the microorganism in $\text{Group I}$ with their fermentation products in $\text{Group II}$.$\begin{array}{|l|l|l|l|} \hline & \textbf{Group I} && \textbf{Group II}...

$\textit{Saccharomyces cerevisiae}$ produces ethanol by fermentation. The theoretical yield of ethanol from $2.5$ g of glucose is _________ g.

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 ...

Cytoplasmic extract from the wild type strain of a bacterium has the ability to convert a colorless substrate $(S)$ to a colored product $(P)$ via three colorless interme...

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...

The growth medium for mammalian cells contains serum. One of the major functions of serum is to stimulate cell growth and attachment. However, it must be filter sterilize...

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 antibiotics in $\text{Group I}$ wiith the targets in $\text{Group II}$.$\begin{array}{|l|l|l|l|} \hline & \text{Group I} & & \text{Group II} \\ \hline P. & \t...

In nature, $\text{Agrobacterium tumefaciens}$ mediated infection of plant cells leads toP. crown gall disease in plantsQ. hairy root disease in plantsR. transfer of $\tex...

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} \...

Phylum proteobacteria is subdivided into $\alpha-, \beta-, \gamma-, \delta-$ and $\epsilon-$ proteobacteria based on$G+C$ content$23S\; rRNA$ sequences$tRNA$ sequences$16...

In nature, the horizontal gene transfer across bacteria is mediated bygene cloning followed by transformationconjugation and transformationconjugation onlytransformation ...

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...

Match the organisms in Group I with the entries in Group II.$\begin{array}{|l|l|l|l|} \hline & \textbf{Group I}. && \textbf{Group II} \\ \hline P. & \textit{Clostridium...

Determine the correctness or otherwise of the following $Assertion$ (a) and $Reason$ (r).$Assertion:$ Cell mass yield of a methylotrophic yeast is more on methanol compar...

In an exponentially growing batch culture of $\text{Saccharormyces cerevisiae}$, the cell density is 20 ${gl^{-1}}$ (DCW), the specific growth rate ($\mu$) is 0.4 ${h^{-1...

In transmission electron microscopy, electron opacity is greatly enhanced by treating the specimen withferrous ammonium sulfateuranium acetatesodium chloridebasic fuchsin

Mammalian cells in active growth phase were seeded at a density of $1 \times 10^5$ cells/ml. After $72$ hours, $1 \times 10^6$ cells/ml were obtained. The population doub...

Match the industrial products mentioned in Group I with their producer organisms in Group II$\begin{array}{|l|l|l|l|} \hline & \textbf{Group I} && \textbf{Group II} \\ \h...

Which of the following are true about bacterial superoxide dismutase?Present in obligate aerobesPresent in facultative anaerobesPresent in aerotolerant anaerobesAbsent in...

Which of the following are true with regard to anaerobic respiration in bacteria?The final electron acceptor is an inorganic substance other than molecular oxygenThe numb...