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Previous Year Questions

TLS Online TPP Program

QUESTION ID:1

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

QUESTION ID:2

Which family of viruses has single stranded DNA?

QUESTION ID:3

What will be the binding status of regulatory proteins in lac operon when concentrations of both lactose and glucose are very low in the culture medium?

QUESTION ID:4

Which of the following are TRUE for Treponema pallidum?
P. It is the causative agent of syphilis
Q. It is a spirochete
R. It is a non-motile bacterium
S. It is generally susceptible to penicillin
Choose the correct combination.

QUESTION ID:5

In a typical mitotic cell division cycle in eukaryotes, M phase occurs immediately after the

QUESTION ID:6

Which one of the following is NOT a therapeutic agent based on nucleic acid for the treatment of genetic disorders?

QUESTION ID:7

ATP biosynthesis takes place utilizing the H+ gradient in mitochondria and chloroplasts. Identify the correct sites of H+ gradient formation.

QUESTION ID:8

Which one of the following is NOT an algorithm for building phylogenetic trees?

QUESTION ID:9

Cesium chloride density gradient centrifugation is commonly used for the separation of DNA molecules. The buoyant density, ρ, of a double stranded Cs+DNA is given by the equation
ρ = 1.66 + 0.098XG+C
where X G+C denotes

QUESTION ID:10

Disaccharide molecules that contain glycosidic linkage are

QUESTION ID:11

Junctional diversity of antibody molecules results from

QUESTION ID:12

Which one of the following is NOT used for the measurement of cell viability in animal cell culture?

QUESTION ID:13

Which one of the following techniques relies on the spin angular momentum of a photon?

QUESTION ID:14

Which one of the following statements is NOT true?

QUESTION ID:15

Based on their function, find the ODD one out.

QUESTION ID:16

Prandtl number is the ratio of

QUESTION ID:17

Fed batch cultivation is suitable for which of the following?
P. Processes with substrate inhibition
Q. Processes with product inhibition
R. High cell density cultivation

QUESTION ID:18

A biological process is involved in the ________ treatment of industrial effluent.

QUESTION ID:19

In dead-end filtration, rate of filtration is

QUESTION ID:20

The power required for agitation of non-aerated medium in fermentation is ________ kW. Operating conditions are as follows:
Fermentor diameter = 3 m
Number of impellers = 1
Mixing speed = 300 rpm
Diameter of the Rushton turbine = 1 m
Viscosity of the broth = 0.001 Pa.s
Density of the broth = 1000 kg.m-3
Power number = 5

QUESTION ID:21

Which one of the following is the most suitable type of impeller for mixing high viscosity (viscosity > 10^5 cP) fluids?

QUESTION ID:22

Runs scored by a batsman in five one-day matches are 55, 75, 67, 88 and 15. The standard deviation is __________________.

QUESTION ID:23

The positive Eigen value of the following matrix is ______________.

QUESTION ID:24

The Laplace transform F(s) of the function f(t) = cos (at), where a is constant, is _____________.

QUESTION ID:25

The value of the integral
  _____________________.

QUESTION ID:26

Which combination of the following statements is CORRECT for cyanobacteria?
P. They can perform oxygenic photosynthesis
Q. Usually filamentous forms are involved in nitrogen fixation
R. Nitrogen fixation occurs in heterocysts
S. They cannot grow in a mineral medium exposed to light and air

QUESTION ID:27

Which set of the following events occurs during the elongation step of translation?
P. Attachment of mRNA with the smaller subunit of ribosome
Q. Loading of correct aminoacyl-tRNA into the A site
R. Formation of a peptide bond between the amino acyl-tRNA in the A site and the peptide
chain that is attached to the peptidyl-tRNA in the P site
S. Dissociation of the ribosomal subunits
T. Translocation of peptidyl-tRNA from the A site to the P site of the ribosome

QUESTION ID:28

A DNA sequence, 5’-ATGGACGTGCTTCCCAAAGCATCGGGC-3’, is mutated to obtain
P. 5’-ATGGACGTGCTTCaCAAAGCATCGGGC-3’
Q. 5’-ATGGACGTGCTTCCCgAAAGCATCGGGC-3’
R. 5’-ATGGACGTGCTTCC-AAAGCATCGGGC-3’
S. 5’-ATGGACGTGCTTCCCAAtGCATCGGGC-3’
T. 5’-ATGGACGaGCTTCCCAAAGCATCGGGC-3’
Which of the above mutant sequences DO NOT have frame-shift?

QUESTION ID:29

Which of the following events occur during the stationary phase of bacterial growth?
P. Rise in cell number stops
Q. Spore formation in some Gram-positive bacteria such as Bacillus subtilis
R. Cell size increases in some Gram-negative bacteria such as Escherichia coli
S. Growth rate of bacterial cells nearly equals their death rate
T. Decrease in peptidoglycan crosslinking

QUESTION ID:30

Select the CORRECT combination of genetic components that are essential for the transfer of TDNA segment from Agrobacterium tumefaciens to plant cells.

QUESTION ID:31

Match the secondary metabolites (Column-I) with the corresponding plant species (Column-II).


QUESTION ID:32

A variety of genetic elements are used in the transgenic plant research. Match the genetic elements (Column-I) with their corresponding source (Column-II).

QUESTION ID:33

Match the type of chromosomal inheritance (Column-I) with the corresponding genetic disease or trait (Column-II).

QUESTION ID:34

A crossing was performed between the genotypes DdEeFfgg and ddEeFfGg. Assuming that the allelic pairs of all genes assort independently, the proportion of progeny having the genotype ddeeffgg is expected to be ______________%.

QUESTION ID:35

The equilibrium potential of a biological membrane for Na+ is 55 mV at 37 ⁰C. Concentration of Na+ inside the cell is 20 mM. Assuming the membrane is permeable to Na^+ only, the Na^+ concentration outside the membrane will be ______________ mM. (Faraday constant: 23062 cal.V-1.mol^-1, Gas constant: 1.98 cal.mol-1.K^-1)

QUESTION ID:36

A 1.2 kb DNA fragment was cloned into BamHI and EcoRI sites located on a 2.8 kb cloning vector. The BamHI and EcoRI sites are adjacent to each other on the vector backbone. The vector contains an XhoI site located 300 bp upstream of the BamHI site. An internal XhoI site is present in the gene sequence as shown in the figure. The resultant recombinant plasmid is digested with EcoRI and XhoI and analyzed through 1% agarose gel electrophoresis. Assuming complete digestion with EcoRI and XhoI, the DNA fragments (in base pairs) visible on the agarose gel will correspond to:

QUESTION ID:37

Find the INCORRECT combination.

QUESTION ID:38

Which of the following statement(s) is/are CORRECT for antigen activated effector T cells?
P. CD4+ cells make contact with macrophages and stimulate their microbicidal activity
Q. CD4+ cells make contact with B cells and stimulate them to differentiate into plasma cells
R. CD8+ cells make contact with B cells and stimulate them to differentiate into plasma cells
S. CD8+ cells make contact with virus infected cells and kill them

QUESTION ID:39

Which one of the following statements regarding G proteins is INCORRECT?

QUESTION ID:40

In animal cell culture, a CO2 enriched atmosphere in the incubator chamber is used to maintain the culture pH between 6.9 and 7.4. Which one of the following statements is CORRECT?

QUESTION ID:41

Choose the CORRECT combination of True (T) and False (F) statements about microcarriers used in animal cell culture.
P. Higher cell densities can be achieved using microcarriers
Q. Microcarriers increase the surface area for cell growth
R. Microcarriers are used for both anchorage- and nonanchorage-dependent cells
S. Absence of surface charge on microcarriers enhances attachment of cells

QUESTION ID:42

In an assay of the type II dehydroquinase of molecular mass 18 kDa, it is found that the Vmax of the enzyme is 0.0134 μmol.min^-1 when 1.8 μg enzyme is added to the assay mixture. If the Km for the substrate is 25 μM, the kcat/Km ratio will be ___________________×104 M^-1.^s-1.

QUESTION ID:43

The molar extinction coefficients of Trp and Tyr at 280 nm are 5690 and 1280 M-1.cm-1, respectively. The polypeptide chain of yeast alcohol dehydrogenase (37 kDa) contains 5 Trp and 14 Tyr residues. The absorbance at 280 nm of a 0.32 mg.mL-1 solution of yeast alcohol dehydrogenase measured in a cuvette of 1 cm pathlength will be ________________.
(Assume that the molar extinction coefficient values for Trp and Tyr apply to these amino acids in the yeast alcohol dehydrogenase).

QUESTION ID:44

The activity of lactate dehydrogenase can be measured by monitoring the following reaction:


The molar extinction coefficient of NADH at 340 nm is 6220 M^-1.cm^-1. NAD+ does not absorb at this wavelength. In an assay, 25 μL of a sample of enzyme  (containing 5 μg protein per mL) was added to a mixture of pyruvate and NADH to give a total volume of 3 mL in a cuvette of 1 cm pathlength. The rate of decrease in absorbance at 340 nm was 0.14 min^-1. The specific activity of the enzyme will be _______________ μmol.min^-1.mg^-1.

QUESTION ID:45

Analysis of a hexapeptide using enzymatic cleavage reveals the following result:
 Amino acid composition of the peptide is: 2R, A,V, S, Y
Trypsin digestion yields two fragments and the compositions are: (R, A, V) and (R, S, Y)
 Chymotrypsin digestion yields two fragments and the compositions are: (A, R, V, Y) and (R, S)
 Digestion with carboxypeptidase A yields no cleavage product.
Given: Trypsin cleaves at carboxyl side of R. Chymotrypsin cleaves at carboxyl side of Y. Carboxypeptidase A cleaves at amino side of the C-terminal amino acid (except R and K) of the peptide.
The correct amino acid sequence of the peptide is:

QUESTION ID:46

The empirical formula for biomass of an unknown organism is . To grow this organism, ethanol (C2H5OH) and ammonia are used as carbon and nitrogen sources, respectively. Assume no product formation other than biomass. To produce 1 mole of biomass from 1 mole of ethanol, the number of moles of oxygen required will be _______________.

QUESTION ID:47

Saccharomyces cerevisiae is cultured in a chemostat (continuous fermentation) at a dilution rate of 0.5 h^-1. The feed substrate concentration is 10 g.L^-1. The biomass concentration in the chemostat at steady state will be _____________ g.L^-1
Assumptions: Feed is sterile, maintenance is negligible and maximum biomass yield with respect to substrate is 0.4 (g biomass per g ethanol).
Microbial growth kinetics is given by 

where μ is specific growth rate (h-1), μm = 0.7 h^-1, Ks = 0.3 g.L^-1 and s is substrate concentration (g.L^-1).

QUESTION ID:48

Decimal reduction time of bacterial spores is 23 min at 121 ⁰C and the death kinetics follow first order. One liter medium containing 10^5 spores per mL was sterilized for 10 min at 121 ⁰C in a batch sterilizer. The number of spores in the medium after sterilization (assuming destruction of spores in heating and cooling period is negligible) will be ___________×10^7.

QUESTION ID:49

A bioreactor is scaled up based on equal impeller tip speed. Consider the following parameters for small and large bioreactors:

Assuming geometrical similarity and the bioreactors are operated in turbulent regime, what will be P2/P1?

QUESTION ID:50

An enzyme converts substrate A to product B. At a given liquid feed stream of flow rate 25 L.min-1 and feed substrate concentration of 2 mol.L-1, the volume of continuous stirred tank reactor needed for 95% conversion will be _____________ L.
Given the rate equation:

where ̶ rA is the rate of reaction in mol.L^-1.min^-1 and CA is the substrate concentration in mol.L^-1 Assumptions: Enzyme concentration is contant and does not undergo any deactivation during the reaction.

QUESTION ID:51

A protein is to be purified using ion-exchange column chromatography. The relationship between HETP (Height Equivalent to Theoretical Plate) and the linear liquid velocity of mobile phase is given by:

where H is HETP (m) and u is linear liquid velocity of mobile phase (m.s^-1). The values of A, B and C are 3×10^-8 m2.s^-1, 3 s and 6×10^-5 m, respectively. The number of theoretical plates based on

minimum HETP for a column of 66 cm length will be ___________.

QUESTION ID:52

An enzyme is immobilized on the surface of a non-porous spherical particle of 2 mm diameter. The immobilized enzyme is suspended in a solution having bulk substrate concentration of 10 mM. The enzyme follows first order kinetics with rate constant 10 s^-1 and the external mass transfer coefficient is 1 cm.s^-1. Assume steady state condition wherein rate of enzyme reaction (mmol.L^-1.s^-1) at the surface is equal to mass transfer rate (mmol.L^-1.s^-1). The substrate concentration at the surface of the immobilized particle will be ________ mM.

QUESTION ID:53

 The initial conditions for this second order homogeneous differential equation are
y(0) = 1 and dy/dx  = 3 at x = 0
The value of y when x = 2 is ___________.

QUESTION ID:54

The value of determinant A given below is __________ .


QUESTION ID:55

Consider the equation

Given a = 4, b = 1 and c = 9, the positive value of S at which V is maximum, will be _______.

QUESTION ID:56

The volume of a sphere of diameter 1 unit is ________ than the volume of a cube of side 1 unit.

QUESTION ID:57

The unruly crowd demanded that the accused be _____________ without trial.

QUESTION ID:58

Choose the statement(s) where the underlined word is used correctly:
(i) A prone is a dried plum.
(ii) He was lying prone on the floor.
(iii) People who eat a lot of fat are prone to heart disease

QUESTION ID:59

Fact: If it rains, then the field is wet.
Read the following statements:
(i) It rains
(ii) The field is not wet
(iii) The field is wet
(iv) It did not rain
Which one of the options given below is NOT logically possible, based on the given fact?

QUESTION ID:60

A window is made up of a square portion and an equilateral triangle portion above it. The base of the triangular portion coincides with the upper side of the square. If the perimeter of the window is 6 m, the area of the window in m^2 is ___________.

QUESTION ID:61

Students taking an exam are divided into two groups, P and Q such that each group has the same number of students. The performance of each of the students in a test was evaluated out of 200 marks. It was observed that the mean of group P was 105, while that of group Q was 85. The standard deviation of group P was 25, while that of group Q was 5. Assuming that the marks were distributed on a normal distribution, which of the following statements will have the highest probability of being TRUE?

QUESTION ID:62

A smart city integrates all modes of transport, uses clean energy and promotes sustainable use of resources. It also uses technology to ensure safety and security of the city, something which critics argue, will lead to a surveillance state.
Which of the following can be logically inferred from the above paragraph?
(i) All smart cities encourage the formation of surveillance states.
(ii) Surveillance is an integral part of a smart city.
(iii) Sustainability and surveillance go hand in hand in a smart city.
(iv) There is a perception that smart cities promote surveillance.

QUESTION ID:63

Find the missing sequence in the letter series.
B, FH, LNP, _ _ _ _.

QUESTION ID:64

The binary operation □ is defined as a □ b = ab+(a+b), where a and b are any two real numbers. The value of the identity element of this operation, defined as the number x such that a □ x = a, for any a, is .

QUESTION ID:65

Which of the following curves represents the function  Here, x represents the abscissa and y represents the ordinate.