List of practice Questions

The order of genes present in a chromosome is as follows.

Which rearrangement represents a paracentric inversion?

Wires W$_1$ and W$_2$ are made of same material having the breaking stress of 1.25$\times$10$^9$ N/m$^2$. W$_1$ and W$_2$ have cross-sectional area of 8$\times$10$^{-7}$ m$^2$ and 4$\times$10$^{-7}$ m$^2$, respectively. Masses of 20 kg and 10 kg hang from them as shown in the figure. The maximum mass that can be placed in the pan without breaking the wires is _________ kg. (Use g = 10 m/s$^2$)

A bullet of 10 g, moving with velocity v, collides head-on with the stationary bob of a pendulum and recoils with velocity 100 m/s. The length of the pendulum is 0.5 m and mass of the bob is 1 kg. The minimum value of v = _________ m/s so that the pendulum describes a circle. (Assume the string to be inextensible and g = 10 m/s$^2$)

A bacterium produces acetic acid from ethanol as per the following reaction $2 CH_3CH_2OH + 2O_2 \rightarrow 2CH_3COOH + 2H_2O$.
The maximum thermodynamic yield of acetic acid from ethanol in g g$^{-1}$ (rounded to two decimals) is $\underline{\hspace{1cm}}$.

In a random mating population, the frequency of Y allele is 0.70. The frequency of Yy heterozygotes is $\underline{\hspace{1cm}}$.

A batch cultivation of E. coli follows zeroth order Monod kinetics. Growth stops when dissolved oxygen reaches 10% of saturation. The oxygen mass transfer coefficient is $k_La = 80\ \text{h}^{-1}$. Saturation dissolved oxygen = 0.007 kg m$^{-3}$. If maximum specific growth rate = 0.2 h$^{-1}$ and yield coefficient $Y_{X/O_2} = 1.5\ (\text{kg cells})(\text{kg O}_2)^{-1$, then the final biomass concentration (kg m$^{-3}$) is $\underline{\hspace{1cm}}$.}

Milk flowing through a stainless steel inner tube (40 mm inner diameter) of a double tube-type heater is heated from 10$^\circ$C to 85$^\circ$C by steam condensing at 120$^\circ$C. Total heat transferred is 146200 kcal h$^{-1}$, and overall heat transfer coefficient is 750 kcal h$^{-1}$ m$^{-2}$ $^\circ$C$^{-1}$. The total length of the heating tube in m (rounded to one decimal place) is $\underline{\hspace{1cm}}$.

A DNA solution of 50 $\mu$g mL$^{-1}$ gives absorbance of 1.0 at 260 nm. A 20 $\mu$L aliquot from a 50 $\mu$L purified plasmid solution is diluted to 1000 $\mu$L. The diluted solution gives absorbance 0.550 at 260 nm. The purified plasmid concentration in $\mu$g $\mu$L$^{-1}$ (rounded to two decimals) is $\underline{\hspace{1cm}}$.

The possible number of SalI restriction sites in a 9 kb double-stranded DNA with equal base proportion (nearest integer) is $\underline{\hspace{1cm}}$.

A 0.1 mL aliquot of a bacteriophage stock having a concentration of $4 \times 10^9$ phages mL$^{-1}$ is added to 0.5 mL of E. coli culture having $2 \times 10^8$ cells mL$^{-1}$. The multiplicity of infection is $\underline{\hspace{1cm}}$.

If the area of a triangle with vertices $(k, 0)$, $(2, 0)$ and $(0, -2)$ is 2 square units, the value of $k$ is $\underline{\hspace{1cm}}$.

In a chemostat with dilution rate 0.8 h$^{-1}$, biomass concentration = 8 mol m$^{-3}$, and specific product formation rate = 0.2 (mol product)(mol biomass)$^{-1}$ h$^{-1}$, the steady-state product concentration (mol m$^{-3}$) is $\underline{\hspace{1cm}}$.

If the values of random variables $X,Y$ are (121,360), (242,364), (363,362), the correlation coefficient (rounded to one decimal place) is $\underline{\hspace{1cm}}$.

It is desired to scale-up a fermentation from 1 L to 1000 L vessel by maintaining a constant power-to-volume ratio. The small fermenter is operated at an agitator speed of 300 rpm. If the value of scale-up factor is 10, agitator speed in rpm (rounded off to the nearest integer) for the large fermenter is $\underline{\hspace{1cm}}$.

The specific growth rate of a mold is 0.15 h$^{-1}$. If the cell concentration at 30 h is 33 g L$^{-1}$, the concentration at 24 h (rounded to nearest integer) is $\underline{\hspace{1cm}}$.