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Previous Year Questions

TLS Online TPP Program

QUESTION ID:1

The common feature of Rho-independent and Rho-dependent termination of transcription is:

QUESTION ID:2

During infection by single stranded RNA viruses, host immune system distinguishes viral RNA from the host RNA based on:

QUESTION ID:3

The deletion of gene X in mice did not result in any abnormality. Further, to investigate the function of the gene, at least five null mice of the same sex are needed. What is the minimum number of pups from heterozygous parents to be screened to obtain the required number?

QUESTION ID:4

The Carbon (C1) of glucose is labelled with 14C (specific activity of 10 mCi/mmole). After one round of glycolysis, the specific activity of radiolabelled pyruvate is:

QUESTION ID:5

Helicobacter pylori survives in the acidic environment of the stomach because it:

QUESTION ID:6

During DNA replication the newly generated strand remains attached to the template. However, during transcription newly synthesized RNA dissociates from the template. This is achieved by:

QUESTION ID:7

Rag1 null mice are susceptible to infection because:

QUESTION ID:8

The restriction site for Van91I is 5′ CCANNNN↓NTGG 3′. How many times can Van91I cut a 4 Mb bacterial genome with 50% GC content?

QUESTION ID:9

Phosphorylation of proteins is a typical post-translational modification which modulates their activities. Which one of the following amino acid residues can be phosphorylated?

QUESTION ID:10

Positive and negative selection markers are utilized to screen for recombinants from wild type populations. Which one of the following can be used for negative selection in bacteria?

QUESTION ID:11

A mammalian cell culture is treated with cycloheximide. Protein synthesis of cells after treatment was recorded through incorporation of labeled amino acids. In which of the following organelles will fresh protein synthesis be detected?

QUESTION ID:12

A scientist aims to identify a binding site for a new transcriptional anti-terminator protein. Which one of the following techniques will be most appropriate for this experiment?

QUESTION ID:13

Primer extension is a technique employed for mapping the:

QUESTION ID:14

UGA is NOT a stop codon in:

QUESTION ID:15

A recombinant plasmid is introduced with adenovirus to specifically label liver cells with GFP. Which gene promoter will be most optimal for specific expression of GFP?

QUESTION ID:16

The schematic represents the basic structural components of a 


QUESTION ID:17

An in vitro translation system containing microsomes was used to translate an mRNA encoding a secretory protein lacking the stop codon. Which one of the following outcomes can be expected?

QUESTION ID:18

The result of an in vitro phosphorylation assay of a protein using γ-32P ATP in the presence of various kinases is shown below. The bands represent phosphorylated proteins detected.
1. Lane 1: No kinase 2. Lane 2: Kinase 3. Lane 3 Kinase 2 followed by inactivation of kinase and subsequent addition of kinase 3 4. Lane 4: Kinase 3 followed by inactivation of kinase and subsequent addition of kinase 2 
Based on the autoradiograph shown above it can be concluded that:

QUESTION ID:19

During subcellular fractionation, a protein is recovered in the membrane fraction. However, upon washing the membrane fraction with high salt, the protein is obtained in the soluble fraction. The mode of association of the protein with the membrane is via:

QUESTION ID:20

Effective oral rehydration therapy requires the presence of both Na+ and glucose because the intestinal epithelial cells express a:

QUESTION ID:21

The Warburg effect in cancers refers to their ability to:

QUESTION ID:22

In a migrating cell the relative position of the ___________ and the ________ determines the polarity of the cell.

QUESTION ID:23

During apoptosis, lipid asymmetry is lost permitting Annexin V to bind to _______ in the outer leaflet of the plasma membrane.

QUESTION ID:24

A cargo has to be delivered from the center of the cell to the cell periphery using the microtubule network. To which protein does it need to be associated with?

QUESTION ID:25

The graph below shows the excitation and emission spectra of three fluorophores: CFP, GFP and YFP. If you were to design an experiment to image two fluorescently labelled proteins inside the same cell, which is the best combination to use? 

QUESTION ID:26

Deamination of which of the following bases will NOT be recognized by the DNA damage repair machinery?

QUESTION ID:27

Arrange the following compounds based on increasing order of acid strength:


QUESTION ID:28

Which of the following compound(s) on oxidation gets converted into optically active tartaric acids?

QUESTION ID:29

Normal bilirubin (4Z, 15Z isomer) undergoes structural isomerisation on absorption of blue-green light (460 – 490 nm). For this reaction, which one of the following statements is TRUE?

QUESTION ID:30

SCID mice lack T-cells owing to the:

QUESTION ID:31

Anti-human μ chain antibody is specific for epitopes present in the:

QUESTION ID:32

Hapten-carrier hypothesis was useful in the designing of the vaccine for:

QUESTION ID:33

Tetanus toxoid is a protein that has been chemically treated to retain its:

QUESTION ID:34

Haemolytic disease of the new born called erythroblastosis fetalis commonly develops in mothers with repeated pregnancies owing to the activation of:

QUESTION ID:35

Human olfactory receptors are:

QUESTION ID:36

Primary neurotransmitter that plays a role in sleep, appetite, arousal and mood is:

QUESTION ID:37

For some people it is a popular herb added in food for flavour, but for others it tastes like soap due to a mutation in OR6A2 receptor. The herb is:

QUESTION ID:38

Chromosome complement of river vs swamp domestic water buffalo is:

QUESTION ID:39

Which one of the following animal diseases was officially declared eradicated by FAO in the year 2011?

QUESTION ID:40

Peste des petits ruminants (PPR) also known as “goat plague”, a viral disease of goats and sheep is caused by:

QUESTION ID:41

Which of these is used as a preferred inhalation anaesthetic for laboratory animals?

QUESTION ID:42

A1/A2 cow milk are genetic variants of the beta casein milk protein that differ by a single amino acid at position 67. The variants for A1 and A2 are:

QUESTION ID:43

Dental formula of cattle older than 4 years is:

QUESTION ID:44

In utero microcephaly is caused by:

QUESTION ID:45

Labels on the tubes containing Fab and F(ab′)2 fragments of anti-SRBC were dislodged. Recommend one of the following techniques to identify the correct fragments in the tube:

QUESTION ID:46

Two cell lines (Vero and SP2/O-Ag14) were cross contaminated. In order to confirm the homogeneity of the cell lines, which of the following approaches would you use?

QUESTION ID:47

Match the genus listed in A with the features in B: 


QUESTION ID:48

Vitamin D3 formed in the skin is converted to 1,25-dihydroxycholecalciferol in the:

QUESTION ID:49

Recently US FDA approved CAR-T treatment is a

QUESTION ID:50

β- Glucans protect aquaculture organisms from various pathogenic strains because they:

QUESTION ID:51

Which one of the following is used for culturing Perna viridis?

QUESTION ID:52

From the table below, match the pellagic zones with their respective depths and choose the correct option:

QUESTION ID:53

Dead zones in oceans refer to:

QUESTION ID:54

Gynogenesis in fishes is achieved by:

QUESTION ID:55

A wastewater sample has COD of 1 g/L of which 80% is the BOD. During partial aerobic oxidation only 200 mg of COD was converted to CO2 and H2O. The remaining BOD (mg/L) is:

QUESTION ID:56

A microbial community has grown on starch anaerobically and it produced a mixture of metabolites with the following composition: glucose, disaccharides, acetate, butyric acid, butanol and carbon dioxide. This microbial community is comprised of:

QUESTION ID:57

In an air sample, 12% particulate matter is of around 25 nm size, 35% around 10 nm, 30% around 5 nm and remaining are 2.5 nm or smaller. The respiratory particulate matter in this sample is:

QUESTION ID:58

A mixture of food waste on inorganic analysis was found to contain Cl-, SO4 -, NO3 -, NH4+ ion. Successful anaerobic digestion by a mixed microbial community will result in biogas having the following gases:

QUESTION ID:59

A bioremediation mesocosm experiment has been carried out on a plot with 250 ppm aromatic molecules as contaminants. After 15 days the level of aromatic molecules came down to 100 ppm at a temperature of 48 ± 2°C. The electrical conductance of this site has increased over time because of the

QUESTION ID:60

Internal coordinates for representation of the three-dimensional structure of a protein consists of:

QUESTION ID:61

Cis-peptide unit corresponds to the O-C-N-H dihedral angle (degrees) of:

QUESTION ID:62

Which of the following corresponds to the amino acid pair having maximum and minimum number of allowed conformations in the Ramachandran plot?

QUESTION ID:63

If the energy of a protein structure is calculated using molecular mechanics forcefield, which of the following energy components CANNOT have a negative value?

QUESTION ID:64

X, Y and Z correspond to three different conformers of an 18-residue peptide, where X: α helix, Y: β strand and Z: 310 helix. Which of the following correspond to the conformers in the decreasing order of end to end distance?

QUESTION ID:65

Which one of the following protein structure prediction methods is based on the principle of locating lowest energy minimum in the conformation space of a protein?

QUESTION ID:66

Which one of the following can be used to measure the extent of similarity between the predicted structure of a protein and its experimentally determined structure?

QUESTION ID:67

The PROSITE pattern representing the conserved sequence motif for a new family of AMP binding protein is [LIVMFY]-X(2)-[STG]-[STAG]-G-[ST]. You are given a sequence of a 15-amino acid stretch starting from the first residue of the motif. Which one of the following proteins is likely to have AMP binding function?

QUESTION ID:68

Dot matrix analysis of the amino acid sequences of lambda phage cI (horizontal sequence) and phage P22 c2 (vertical sequence) repressors is shown below. Which one of the following is correct?

QUESTION ID:69

An alignment of two protein sequences showing matches, mismatches and gaps (delta) is given below: 

The similarity score (%) for the above alignment will be: 

QUESTION ID:70

Which one of the following is a depiction of the GenBank sequence entry format?

QUESTION ID:71

Two sequences of comparable length have several regions that align locally, but are separated by other regions that align poorly. Which algorithm can be used to find the highest-scoring alignment between the two sequences?

QUESTION ID:72

A sample Genetic code is given below. 

If an amino acid substitution matrix based on genetic code is derived for sequence alignment and analysis from evolutionary studies, which one of the blowing 5 TRUE? 

QUESTION ID:73

Which one of the following tools can reliably establish an evolutionary link between two proteins and align them even if they share very low degree of sequence similarity?

QUESTION ID:74

Of the two databases A and B, the database A is larger in size than database B. In a BLAST search, a sequence has a highly significant match with the same entry in both the databases. Which of the following is TRUE?

QUESTION ID:75

Parents who appear normal have a child with sickle cell anemia, which is an autosomal recessive trait. The woman becomes pregnant again and is told that she is carrying fraternal twins. What is the probability that both the twins will develop sickle cell anemia?

QUESTION ID:76

The following pedigree shows the inheritance of a human disease. What is the most likely mode of inheritance for this trait and what is the probability that a son of III 1 would be affected by the disease, if III 1 is known to be a carrier.

QUESTION ID:77

A 30 Kb candidate gene linked to prostate cancer from a patient was digested with XhoI. Following Southern hybridization of the digested products with the full-length gene probe, three bands of 15, 10 and 5 Kb sizes were obtained. However, an identical experiment in normal individuals gave a 15 Kb fragment. This could be due to:

QUESTION ID:78

In a given population, 1 out of 400 individuals has cancer caused by a recessive allele ‘p’. Assuming the population is in Hardy-Weinberg equilibrium, what is the expected proportion of individuals who carry the ‘p’ allele but do not develop cancer?

QUESTION ID:79

Color blindness in human beings is an X-linked trait. A color-blind man has a 45, X daughter who is also color-blind. The nondisjunction that leads to the 45, X daughter occurred in which parent and in which meiotic division?

QUESTION ID:80

A marker present outside the targeted QTL used to check the crossing over is called:

QUESTION ID:81

Linkage disequilibrium (LD) decay is:

QUESTION ID:82

‘Gene for gene’ hypothesis states that:

QUESTION ID:83

In an ordered tetrad analysis, if the two genes are not linked, the ………… will be almost equal.

QUESTION ID:84

Assume that a marker M1 is present 5 cM away on one side of a gene “X” (a desirable allele of the gene), while marker M2 is present 10 cM away on the other side of the gene. The donor’s genotype is M1M1XXM2M2, while the recipient has m1m1xxm2m2 genotype. A cross was made between these two individuals. The F1 is crossed to recipient. The progeny of this cross had 1000 plants. How many plants from this progeny will have both the markers (M1 & M2) present while the desired gene is absent? (Assume no interference)

QUESTION ID:85

Maize transgenic for bacterial CspA (a RNA chaperone) imparts tolerance to:

QUESTION ID:86

Assume gene “A” is dominant over “a” and “B1” is codominant over “B2” in petunia. A cross is made between two individuals – AAB1B2 x aaB1B2. Assuming that there is no gene interaction, the progeny will segregate in a phenotypic ratio of:

QUESTION ID:87

A multiline variety is:

QUESTION ID:88

A variety “X” is a donor for resistance to blast, but it has an undesirable gene for lodging susceptibility that is tightly linked to the blast resistant gene. The best breeding method which has high probability of breaking this linkage is:

QUESTION ID:89

Upon application of the inhibitor, DBMIB (Dibromothymoquinone) which one of the following events in the chloroplast electron transport chain will NOT take place?

QUESTION ID:90

The reduction phase of Calvin-Benson cycle in Arabidopsis is inhibited. This can be attributed to the inactivation of:

QUESTION ID:91

Sucrose-phosphate synthase (SPS) is inhibited by SPS-kinase and activated by SPS-phosphatase. It is known that a high ratio of Glucose-6-phosphate to inorganic phosphate maintains SPS in its active form. Which one of the following statements is true?

QUESTION ID:92

The bacterial flagellin activates a typical MAPK cascade consisting of MEKK1-MKK4-MPK6 leading to the activation of ACS6 enzyme involved in ethylene biosynthesis in plants. Which one of the following events will be true in a transgenic Arabidopsis plant overexpressing the constitutively active form of MKK4?

QUESTION ID:93

Which one of the following statements is correct during gibberellic acid (GA) signal transduction in plants?

QUESTION ID:94

In CLAVATA (clv) mutant of Arabidopsis, Shoot Apical Meristem (SAM) size and expression of WUSCHEL (WUS) is increased. SAM size is reduced in wus mutant plants. Choose the correct statement regarding the function of these two genes:

QUESTION ID:95

Any DNA fragment can be used as a STS marker provided it fulfills one of the following conditions:

QUESTION ID:96

Which one of the following conditions eliminates the possibility of horizontal gene transfer from a transgenic plant?

QUESTION ID:97

Which one of the following transposition events would increase the DNA content in a given cell?

QUESTION ID:98

Flower development in plants is regulated by the ABC model of gene regulation. Members of this gene family are characterized by which one of the following domains?

QUESTION ID:99

In which one of the following PCR assays only one primer is used for amplification?

QUESTION ID:100

Gaps in certain regions of the genome have been observed upon sequencing of a xerohalophyte. Which one of the following databases will NOT be of any use in filling up these gaps?

QUESTION ID:101

One of the most popular genes used for developing rice tolerant to flooding stress is:

QUESTION ID:102

“Refugia” is a practice commonly employed to control

QUESTION ID:103

Oat seeds will usually NOT germinate when exposed to Red (R) and Far red (FR) light in the following order:

QUESTION ID:104

Vir genes are necessary for the transfer of the T-DNA into the host genome. The product of which one of the following genes is tightly associated with the 5′ end of the T-strand and helps in nuclear targeting?

QUESTION ID:105

A microorganism following Monod kinetics is grown in a chemostat with working volume of 5 L and inlet substrate concentration of 1g/L. If the μmax and Ks of the organism are 0.5 h-1 and 0.25g/L respectively, washout occurs when the flow rate (L.h-1) exceeds

QUESTION ID:106

How does the rate of a typical chemical reaction vary as a function of temperature?

QUESTION ID:107

An enzyme follows Michaelis-Menten kinetics with the following parameters: Vmax= 5 mM/s and Km= 2.5 mM. The reaction velocity would be:

QUESTION ID:108

A high cell density fermentation produces recombinant protein product which is 20% of the total cellular protein. The final cell density is 80 OD (1 OD = 0.4g of dry cell wt/L of which 50% is total cellular protein). Then the product concentration (g/L) is:

QUESTION ID:109

In a plug flow bioreactor running at steady state, 12.5% cells are recycled back to the inlet. If the cells grow at μmax=1 h-1 throughout the length of the reactor (L=124 cm), then the flow velocity should be

QUESTION ID:110

In a CSTR, first order reaction takes place converting A to B. If at a dilution rate (D)= 0.5 h-1, 50% of A gets converted to B, then the rate constant ‘k’ of the reaction is:

QUESTION ID:111

In a continuous crystallizer, 100 g of a saturated solution of sugar at 85% (w/w) enters the crystallizer and leaves the crystallizer at 70% (w/w). The weight of input solids converted to crystals (g) in the crystallizer is

QUESTION ID:112

We wish to produce a metabolite ‘X’ whose biosynthetic pathway is feedback inhibited in the wild type strain. A mutation, which leads to overproduction of X, is discovered in the gene coding for a homodimeric enzyme which catalyses the first step in the biosynthetic pathway of ‘X’. This mutation is most likely to occur at:

QUESTION ID:113

A new spherical resin (of radius 300 urn) has been developed in which only the outer layer is activated to a depth of 100 um (as shown in figure). The fraction of the activated volume is: 

QUESTION ID:114

In a fed batch cultivation, a specific growth rate of 0.2/h needs to be maintained. At the start of fedbatch cultivation, 200 mL/h of media is fed to 1000 mL of working volume. Quasi steady state shall be obtained if:

QUESTION ID:115

A recombinant protein is produced in Escherichia coli by two stage continuous cultivation at steady state. Upon induction of the culture in stage II, the specific growth rate of the culture decreased considerably. For an input flow rate in stage I of 100mL/h, a steady rate of product formation can only be obtained

QUESTION ID:116

Consider the scale up of a fermentation from a 10 L to 10,000 L while maintaining geometric similarity. Agitation speed was maintained at 500 rpm in the 10 L fermenter. If scale up is done based on constant tip speed, then the agitation speed in the larger reactor should be ………….rpm

QUESTION ID:117

A culture can grow independently in two carbon sources, glucose and hexadecane. Identify which one of the following statements is TRUE?

QUESTION ID:118

In mammalian cell culture based monoclonal antibody production, perfusion culture is preferred over continuous stirred tank culture, because the process results in:

QUESTION ID:119

A liquid stream is cooled from SOT to 30*C in a double pipe heat exchanger as illustrated below: 

Fluid flowing counter currently with this stream is heated from 15°C to 30°C. Calculate the log mean temperature difference. 

QUESTION ID:120

In a typical fermentation process the volumetric oxygen transfer coefficient (KLa) of the system was found to increase after the addition of antifoam agent. The most probable reason for this is:

QUESTION ID:121

In a batch microbial fermentation process the dissolved oxygen concentration (DOC) remains almost zero during growth. Which of the following methods will you use for the estimation of oxygen transfer rate while the fermentation is in progress?

QUESTION ID:122

Two columns of 1 m and 2 m height and of equal diameter are packed with beads containing immobilized enzyme. Substrate was fed to these two columns at flow rates of 10 mL/min (1 m column) and 20 mL /min (2 m column) and the corresponding conversion efficiencies obtained were 30% and 40% respectively. This demonstrates that the reaction is:

QUESTION ID:123

A food package label displays composition of the food product in g/100g as: protein = 8g, fat= 20g, carbohydrate= 60g (of which sugar is 20g). The calorific value of this product before and after complete replacement of sugar (w/w) by a non-calorific sweetener would be:

QUESTION ID:124

Two sucrose solutions ‘A’= 30g/100g and ‘B’= 60 g/100 g have to be mixed to prepare 1 kg of 50g/100g sugar syrup. The amounts of ‘A’ and ‘B’ solutions to be mixed would be:

QUESTION ID:125

A food product having water activity of 0.6 is exposed to conditions of 30°C and 70% R.H. This product will tend to ___________

QUESTION ID:126

The driving force for mass transfer by molecular diffusion is the difference in

QUESTION ID:127

Sedimentation efficiency depends on the relative strength of :

QUESTION ID:128

In anaerobic lactic acid fermentation by bacteria, glucose is partially oxidised to pyruvate followed by reduction to lactate:

QUESTION ID:129

Which one of the following is NOT used for partition based bio-separation?