Recent questions without answers

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...

Yeast converts glucose to ethanol and carbon dioxide by glycolysis as per the following reaction: $$C_6H_{12}O_6 \to 2C_2H_5OH + 2CO_2$$Assuming complete conversion, the ...

First order deactivation rate constants for soluble and immobilized amyloglucosidase enzyme are $0.03 \text{ min}^{-1}$ and $0.005 \text{ min}^{-1}$, respectively. The ra...

Consider a simple uni-substrate enzyme that follows Michaelis-Menten kinetics. When the enzyme catalyzed reaction was carried out in the presence of $10$ nM concentration...

The product of complete digestion of the plasmid shown below with EcoRI and HaeIII was purified and used as a template in a reaction containing Klenow fragment of DNA pol...

A rod shaped bacterium has a length of $2 \: \mu m$, diameter of $1 \mu m$ and density the same as that of water. If proteins constitute $15 \%$ of the cell mass and the ...

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...

$5'$ capping of mRNA transcripts in eukaryotes involves the following events:Addition of GMP on the $5'$ endRemoval of $\gamma$-phosphate of the triphosphate on first bas...

Calculate the following integral (up to two decimal places)$$\displaystyle \int_0^1 (x + 3)(x + 1)dx = \text{ ___________}$$

The probability distribution for a discrete random variable $X$ is given below. $$\begin{array}{|c|c|c|c|c|} \hline X & 1 & 2 & 3 & 4 \\ \hline P(X) & 0.3 & 0.4 & 0.2 & 0...

If $1+r + r^2+ r^3 +\dots \infty = 1.5$, then, $1 + 2r + 3r^2 + 4r^3 + \dots \infty = $ (up to two dcimal places) ________

Moist heat sterilization of spores at $121 ^\circ C$ follows first order kinetics as per the expression: $$\dfrac{dN}{dt}=-k_dN$$ where, $N$ is the number of viable spore...

An aqueous solution containing $6.8$ mg/L of an antibiotic is extracted with amyl acetate. If the partition coefficient of the antibiotic is $170$ and the ratio of water ...

A microbial strain is cultured in a $100$ L stirred fermenter for secondary metabolite production. If the specific rate of oxygen uptake is $0.4 \: h^{-1}$ and the oxygen...

Match the classes of RNA molecules in $\text{Group I}$ with their functions in $\text{Group II}$.$\begin{array}{|l|l|l|l|} \hline & \text{Group I} && \text{Group II} \\ ...

Which one of the following amino acids is catalyzed by activated macrophages to produce reactive nitrogen species?ArginineAsparagineCysteineHistidine

Determine the correctness or otherwise of the following Assertion [a] and the Reason [r]:Assertion: The association constant in water for the G-C base pair is three times...

Which one of the combinations of the following statements is true about antibody structure?Limited proteolysis of rabbit IgG with the enzyme pepsin generates two antigen-...

Which one of the following statements is true with regard to processing and presentation of protein antigens?In the class II MHC pathway, protein antigens in the cytosol ...

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...

Shear stress versus shear rate behavior of four different types of fluids (I, II, III and IV) are shown in the figure below.Which one of the following options is correct?...

Which one of the following is the solution for $\cos^2 x + 2 \cos x + 1 = 0$, for values of $x$ in the range of $0^\circ < x < 360^\circ$$45^\circ$$90^\circ$$180^\circ$$2...

Which one of the following plant secondary metabolites is a natural insecticide?DigitoxinPyrethrinSalicylic acidAvenacin A-$1$

The variable $z$ has a standard normal distribution. If $P(0 \leq z \leq 1)= 0.34$ then $P(z^2 1)$ is equal to (up to two decimal places) ____________

The absorbance of a solution of tryptophan measured at $280$ nm in a cuvette of $2.0$ cm path length is $0.56$ at pH $7$. The molar extinction coefficient $(\varepsilon)$...

A single stem cell undergoes $10$ asymmetric cell divisions. The number of stem cells at the end is _________

Genomic DNA isolated from a bacterium was digested with a restriction enzyme that recognizes a $6$-base pair (bp) sequence. Assuming random distribution of bases, the ave...

In leguminous plants, both the rhizobium genes and the plant genes influence nodulation and nitrogen fixation. Which one of the following functions is NOT encoded by the ...

Which of the following cytokines are endogenous pylogens?Tumor necrosis factor-$\alpha$Interleukin-$1$Transforming growth factor-$\beta$Interleukin-$10$P and Q onlyP and ...

Which one of the following metabolic processes in mammalian cells does NOT occur in the mitochondria?Citric acid cycleOxidative phosphorylationFatty acid $\beta$-oxidatio...

Which one of the following is NOT a principal component of innate immunity?Mucosal epitheliaDendritic cellsComplement systemMemory B-cells

Which of the following technique(s) can be used to study conformational changes in myoglobin?Mass spectrometryFluorescence spectroscopyCircular dichroism spectroscopyLigh...

Which one of the following bioreactor configurations is the basis for a trickling biological filter?Stirred tankPacked bedAir liftFluidized bed

Cell type A secretes molecule X into the culture medium. Cell type B in the same culture responds to the molecule X by expressing protein Y. Which one of the following mo...

Which one of the following statements is true for actin?Actin filament is structurally polarized and the two ends are not identicalDe novo actin polymerization is a singl...

Standard error isthe probability of a type I error in a statistical testthe error in estimating a sample standard deviationthe standard deviation of a variable that follo...

Which one of the following techniques is used to monitor RNA transcripts, both temporally and spatially?Northern blottingIn situ hybridizationSouthern blottingWestern blo...

Consider an unfair coin. The probability of getting heads is $0.6$. If you toss this coin twice, what is the probability that the fast or the second toss is heads?$0.56$$...

If serum is removed from the growth medium of human embryonic kidney cell line (HEK), then the cells willproliferate fasterproliferate normallyundergo cell cycle arrestun...