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Previous Year Questions

TLS Online TPP Program

QUESTION ID:1

The village was nestled in a green spot, _______ the ocean and the hills.

QUESTION ID:2

Disagree : Protest : : Agree : _______
(By word meaning)

QUESTION ID:3

A ‘frabjous’ number is defined as a 3 digit number with all digits odd, and no two adjacent digits being the same. For example, 137 is a frabjous number, while 133 is not. How many such frabjous numbers exist?

QUESTION ID:4

Which one among the following statements must be TRUE about the mean and the median of the scores of all candidates appearing for GATE 2023?

QUESTION ID:5

In the given diagram, ovals are marked at different heights (h) of a hill. Which one of the following options P, Q, R, and S depicts the top view of the hill?


QUESTION ID:6

Residency is a famous housing complex with many well-established individuals among its residents. A recent survey conducted among the residents of the complex revealed that all of those residents who are well established in their respective fields happen to be academicians. The survey also revealed that most of these academicians are authors of some best-selling books.
Based only on the information provided above, which one of the following statements can be logically inferred with certainty?

QUESTION ID:7

Ankita has to climb 5 stairs starting at the ground, while respecting the following rules:
1. At any stage, Ankita can move either one or two stairs up.
2. At any stage, Ankita cannot move to a lower step.
Let 𝐹(𝑁) denote the number of possible ways in which Ankita can reach the 𝑁𝑡ℎ stair. For example, 𝐹(1)=1,𝐹(2)= 2,𝐹(3) = 3.
The value of 𝐹(5) is _______.

QUESTION ID:8

The information contained in DNA is used to synthesize proteins that are necessary for the functioning of life. DNA is composed of four nucleotides: Adenine (A), Thymine (T), Cytosine (C), and Guanine (G). The information contained in DNA can then be thought of as a sequence of these four nucleotides: A, T, C, and G. DNA has coding and non-coding regions. Coding regions—where the sequence of these nucleotides are read in groups of three to produce individual amino acids—constitute only about 2% of human DNA. For example, the triplet of nucleotides CCG codes for the amino acid glycine, while the triplet GGA codes for the amino acid proline. Multiple amino acids are then assembled to form a protein.
Based only on the information provided above, which of the following statements can be logically inferred with certainty?
(i) The majority of human DNA has no role in the synthesis of proteins.
(ii) The function of about 98% of human DNA is not understood.

QUESTION ID:9

Which one of the given figures P, Q, R and S represents the graph of the following function? 

𝑓(𝑥)=| |𝑥+2|−|𝑥−1| |

QUESTION ID:10

An opaque cylinder (shown below) is suspended in the path of a parallel beam of light, such that its shadow is cast on a screen oriented perpendicular to the direction of the light beam. The cylinder can be reoriented in any direction within the light beam. Under these conditions, which one of the shadows P, Q, R, and S is NOT possible?


QUESTION ID:11

Which one among the following mixtures gives a buffer solution in water?

QUESTION ID:12

What is the major product formed in the given reaction?


QUESTION ID:13

The CORRECT order of stability of the given metal oxides is

QUESTION ID:14

Which of the following is/are CORRECT when two single complementary strands of DNA come together to form a double helix at a given temperature?
(∆𝑆 and ∆𝐻 are changes in entropy and enthalpy of the process, respectively.)

QUESTION ID:15

Suitable reagent(s) to bring about the conversion of P to Q in good yield is/are


QUESTION ID:16

Choose the CORRECT trend(s) of the first ionization energies among the following.
(Given: Atomic numbers C: 6; N: 7; O: 8; F: 9; Si: 14; P: 15; S: 16; Cl: 17)

QUESTION ID:17

The depression of freezing point of water (in K) for 0.1 molal solutions of NaCl and Na2SO4 are ∆𝑇1 and ∆𝑇2, respectively. Assuming the solutions to be ideal, the
ratio ∆𝑇1⁄∆𝑇2 is _____________ (rounded off to two decimal places).

QUESTION ID:18

Considering cyclobutane to be planar, the number of planes of symmetry in the following compound is _____________ (in integer).

QUESTION ID:19

The dipole moment (𝜇) of BrF is 1.42 D and the bond length is 176 pm. The atomic charge distribution (𝑞) in the molecule is _____ (rounded off to two decimal places).
(Given: 1 D = 3.34 × 10^ˉ30C m; the factor e (electronic charge) = 1.60 × 10^ˉ19 C)

QUESTION ID:20

Consider two different paths in which the volume of an ideal gas doubles isothermally:
i) Reversible expansion (work done = 𝑤𝑟𝑒𝑣)
ii) Irreversible expansion, with the external pressure equal to the final pressure of the gas (work done = 𝑤𝑖𝑟𝑟𝑒𝑣)


QUESTION ID:21

A mixture of four peptides, PKKRK, RGERV, RYRGV and LVVYP, is loaded onto an ion-exchange column at pH = 7.2. If carboxymethyl (CM) cellulose is used as 
the stationary phase of this column, then which peptide elutes first?


QUESTION ID:22

Match the coordination complexes given in Column I with the most appropriate properties in Column II.
(Given: Atomic numbers of Mn: 25; Co: 27; Ni: 28) 

QUESTION ID:23

Compounds P and Q undergo E2 elimination with reaction rate constants of k1 and k2, respectively, as shown below. Which is/are the CORRECT option(s)?

QUESTION ID:24

According to Hard-Soft Acid-Base (HSAB) principle, the CORRECT option(s) for the solubility trend in water is/are

QUESTION ID:25

Compound X gives alcohol P as the major product for the reaction shown below. Suitable option(s) for X is/are

QUESTION ID:26

The number of radial node(s) for the valence orbital of U(III) ion is _____ (in integer).
(Given: Atomic number of U is 92)

QUESTION ID:27

Eº = 1.10 V for the following cell reaction:

For this reaction, the equilibrium constant is 𝑦 × 1037 at 298 K. The value of 𝑦 is _____ (rounded off to two decimal places).

(Given: F = 96485 C molˉ1, R = 8.314 J Kˉ1molˉ1)


QUESTION ID:28

Determine the correctness or otherwise of the following Assertion [a] and the Reason [r].
Assertion [a]: On a per carbon basis, palmitic acid yields more ATP than glucose.
Reason [r]: Carbons in palmitic acid are more reduced than those in glucose.

QUESTION ID:29

When cell components are fractionated by sedimentation, the correct order (from lower to higher gravitational force, g) in which the components get separated is_______. 

QUESTION ID:30

In a population, the probability of a susceptible individual getting infected with SARS-CoV-2 is low when a majority of individuals in the population becomes immune to this virus. This phenomenon is known as _______.

QUESTION ID:31

Given below are four reactions of the glycolytic pathway catalyzed by the enzymes
E1, E2, E3, and E4, as indicated. Which of these enzymes is/are NOT part of the
gluconeogenesis pathway?

QUESTION ID:32

Which of the following molecules is/are second messenger(s) produced by the phosphoinositide signaling cascade? 

QUESTION ID:33

A protein has seven cysteine residues. The maximum number of disulfide bonds of different combinations that can possibly be formed by these seven cysteine residues 
is _______ (in integer).

QUESTION ID:34

DNA in a 1 cm long chromatin contains 5 × 109 base pairs. The fold compaction of this DNA within the chromatin is _______ (in integer).

QUESTION ID:35

Intracellular concentrations of ATP, ADP, and inorganic phosphate in four cell types are given below. Which one of these cell types has the most negative ∆𝐺 for 
ATP hydrolysis?

QUESTION ID:36

Which one of the following amino acids has more than two acid-base groups?

QUESTION ID:37

Enzyme activity profiles as a function of time in the absence or presence of different types of feedback mechanisms are shown in the figure below. Match the following 
feedback mechanisms with the corresponding profiles in the figure.
(p) No feedback mechanism
(q) Negative feedback mechanism with short delay
(r) Negative feedback mechanism with long delay
(s) Positive feedback mechanism

QUESTION ID:38

A lyophilized sample of 20 nanomoles of an oligonucleotide is dissolved in water and the volume of the solution is made up to 200 µL. The concentration (in µM) of 
the oligonucleotide in this solution is ______ (in integer).

QUESTION ID:39

A linear DNA fragment of 5 kilobase (kb) when completely digested with EcoRI produces 2.5 kb, 1.5 kb, and 1 kb fragments. Complete digestion of the same 5 kb 
fragment with XbaI produces 3.5 kb and 1.5 kb fragments. Which one of the following sets of fragments will be obtained if the 5 kb fragment is fully digested 
with EcoRI and XbaI simultaneously?

QUESTION ID:40

Match the cell types listed in Group I with associated processes listed in Group II.


QUESTION ID:41

Four statements about lipids are given below as options. Choose the statement(s) which is/are CORRECT.

QUESTION ID:42

Which of the following technique(s) can be used to separate proteins according to their molecular weights from a mixture of proteins?

QUESTION ID:43

B cells produce two forms of an immunoglobulin: (i) membrane-bound form, known as B cell receptor (BCR) and (ii) soluble form, known as antibody. Which 
of the following statements is/are CORRECT about BCR and antibody produced by the same B cell?

QUESTION ID:44

A 100 ml solution of pH 10 was well-mixed with a 100 ml solution of pH 4. The pH of the resultant 200 ml solution is ___________ (rounded off to two decimal places).

QUESTION ID:45

An organism uses only the glycerophosphate shunt pathway to transport cytosolic NADH to mitochondria. For every two electrons transported, complex I, complex 
III, and complex IV of the electron transport chain in this organism transport 2.5, 1.5, and 2.0 protons (H+), respectively. The H+ to ATP ratio of FOF1-ATPase of this 
organism is 4.0. Terminal electron acceptor is oxygen. 
The number of ATP molecules synthesized by oxidizing NADH from glycolysis is __________ (rounded off to two decimal places).

QUESTION ID:46

If the extracellular concentration of sodium ion (Na+) is ten times more than its intracellular concentration, then the sodium equilibrium potential at 20 ºC in mV is 
________________ (rounded off to two decimal places). Assume that the membrane is permeable only to Na+ ions. [Use R = 1.987 𝑐𝑎𝑙 𝑑𝑒𝑔−1 𝑚𝑜𝑙−1 and F = 23062 𝑐𝑎𝑙 𝑚𝑜𝑙−1 𝑉−1]

QUESTION ID:47

Which one of the following statements on Casparian strips is correct?

QUESTION ID:48

Rotenone is a chemical often used to kill insect pests on crop plants and fishes in lakes. Rotenone acts by inhibiting electron transport from the NADH dehydrogenase enzyme in Complex I to ubiquinone in the mitochondrial electron transport chain. Which one of the following explains why plants can tolerate rotenone application?

QUESTION ID:49

Although Pseudomonas syringae infection in plants is actively inhibited by the endogenous salicylic acid (SA) of host origin, a successful infection is still established because the bacterium secretes coronatine, an effector molecule. Which one of the following best describes the mode of action of coronatine?

QUESTION ID:50

The schematic depicts an unexpanded plant cell within a hypocotyl with the arrangement of cellulose microfibrils marked on its cell wall.
Which one of the following shapes would most likely result from the expansion of this cell if the pattern of the cellulose fibrils does not change?

QUESTION ID:51

Which one or more of the following statements is/are NOT CORRECT with respect to pollen development in angiosperm?

QUESTION ID:52

Regulation of phosphoenolpyruvate carboxylase (PEPCase) governs CO2 fixation in both C4 and CAM (crassulacean acid metabolism) plants. Which one or more 
of the following statements with respect to PEPCase activity is/are CORRECT?

QUESTION ID:53

Which one or more processes listed below DOES NOT/DO NOT produce carbon dioxide during fermentation?

QUESTION ID:54

The ovule of a diploid species with 2n = 8 undergoes double fertilization. If the pollen is contributed by an individual with meiotic nondisjunction, the chromosome number of the zygote will be _________.

QUESTION ID:55

Match the tasks given in Group I with the associated techniques conventionally used as listed in Group II.

QUESTION ID:56

Periderm is a protective tissue found in stems and roots of gymnosperm and woody dicotyledons. It contributes to the increased thickness by secondary growth. Match the peridermal components given in Group I with the cell/tissue types given in Group II.

QUESTION ID:57

Match the following rice diseases in Group I with their causal agents in Group II.

QUESTION ID:58

Central vascular cylinder or stele consists of the primary vascular system (xylem and phloem) and the associate fundamental tissue. Match the schematics of stele 
in Group I (xylem shown in green, and phloem shown as ) with their respective types in Group II.

QUESTION ID:59

Consider the following four experimental observations (i, ii, iii, iv) on the effect of the FT gene on flowering transition in the shoot apical meristem (SAM) of Arabidopsis thaliana. 
i) The FT promoter is active in leaves alone.
ii) The ft null mutation causes delayed flowering transition of the SAM.
iii) Expressing a recombinant FT protein fused to nuclear localization signal sequence under the endogenous promoter does not rescue the delayed-flowering phenotype of the ft null mutant.
iv) Downregulation of FT transcript in the SAM by RNA interference in the wild-type background does not alter flowering transition.
Which one of the following conclusions best explains the above observations?

QUESTION ID:60

Which one of the options given correctly matches the alkaloids in Group I with their source plants in Group II?

QUESTION ID:61

A drought tolerant rice genotype was found to be associated with a missense mutation in the gene A. Which one or more of the following experiments is/are appropriate to validate whether the mutation in A is the causal factor for drought tolerance?

QUESTION ID:62

Blue light can directly induce opening of stomata. Blue light also triggers photosynthesis in the guard cells, which indirectly induces stomatal opening. Which one or more of the following experimental approaches would test the direct effect of blue light on stomatal opening?

QUESTION ID:63

In a diploid angiosperm species, flower colour is regulated by the R gene. RR and Rr genotypes produce red flowers, whereas the rr genotype produces white flowers. If two individual plants are randomly selected from a large segregating population of a genetic cross between RR and rr parents, the probability of both the plants producing red flowers is _______.
(Rounded off to two decimal places)

QUESTION ID:64

A cytoplasmic male-sterile female plant with the restorer (nuclear) genotype rr is crossed to a male-fertile male plant with the genotype RR. Both RR and Rr can restore the fertility, whereas rr cannot. When an F1 female plant with Rr genotype was test-crossed to a male-fertile male plant with the rr genotype, the percentage of the population that is male fertile would be _______ %. 
(Answer in integer)

QUESTION ID:65

The frequencies for autosomal alleles A and a are p = 0.5 and q = 0.5, respectively, where A is dominant over a. Under the assumption of random 
mating, the mating frequency among dominant parents is _________. 
(Rounded off to two decimal places)

QUESTION ID:66

Which one of the following animals has “Book Lungs” as a respiratory organ?

QUESTION ID:67

Which one of the following describes the “innate behavior” of an animal?A behavior that is triggered due to the change in environment.

QUESTION ID:68

Which one of the following represents a true “Ecological population” ?

QUESTION ID:69

Which of the following animals show “Bottle cells” during the gastrulation stage of development?

QUESTION ID:70

organisms that obtain energy from inorganic compounds are known as

QUESTION ID:71

Which of the following is/are the causative agent(s) of Filariasis?

QUESTION ID:72

In a population of 1000 wild dogs in a grassland, 360 and 480 dogs had black body colour with genotypes BB and Bb, respectively. In the same population, remaining dogs were white in colour with a genotype of bb. Based on this data, the frequency of allele “b” in the population is ______ (round off to one decimal place).

QUESTION ID:73

A mature rat sperm cell has 2.5 μg of genomic DNA that is equivalent of a haploid genome. Compared to this sperm cell, the amount of genomic DNA (in μg) in a somatic cell, which is in the G2 phase of cell cycle, will be _____ (in integer).

QUESTION ID:74

In an experiment, excess amount of bicod mRNA (more than wild-type expression level) was injected into the posterior pole of a wild-type Drosophila embryo at pre-blastodermal stage. Out of the following options, which one represents the best expected phenotype in the resulted developing embryo?

QUESTION ID:75

Match the hormones/precursors listed in Column I with their chemical type in Column II and the tissue of origin listed in Column III

QUESTION ID:76

Match the syndromes listed in Column I with the cause/symptoms listed in Column II


QUESTION ID:77

Match the immunological statements in Column I with the appropriate descriptions from Column II


QUESTION ID:78

Match the standard/stated cofactors in Column I with their respective enzymes in Column II


QUESTION ID:79

The presence of excess glucose has been known to prevent the induction of lac operon as well as other operon controlling enzymes involved in carbohydrate metabolism in E. coli. Which of the following processes define(s) the phenomenon?

QUESTION ID:80

Which of the following techniques is/are used for determining the three-dimensional structure of proteins?

QUESTION ID:81

Among the following statements, which is/are TRUE regarding the replication of DNA?

QUESTION ID:82

Which of the following statements is/are TRUE for Colchicine?

QUESTION ID:83

Wild-type Drosophila females having three linked genes (AABBCC) were crossed with triple recessive mutant (aabbcc) males. The F1 female progenies (AaBbCc) were back crossed with the triple negative mutant (aabbcc) males. The cross resulted in following number of progenies in F2 :

The order of genes as determined from the above data was found to be “ABC” (note that the order is equivalent to “CBA” and the order outside the markers are arbitrary).

The recombination map distance (in centi Morgan) between “A to C” is ______ (round off to one decimal place).

QUESTION ID:84

Monkey pox is caused by a

QUESTION ID:85

The length of a double helical DNA molecule is 13.6 km. If the DNA double helix weighs 1 ×10−18 g per 1000 nucleotide pairs and rise per base pair is 3.4 Å, then weight of the double helical DNA molecule (in nanogram) will be ______ (in integer).

QUESTION ID:86

Which one of the following converts sulfate to hydrogen sulfide?

QUESTION ID:87

Which one of the statements about bacterial flagella is correct?

QUESTION ID:88

Microbial plastics are made from

QUESTION ID:89

The correct sequence of metabolic intermediates in Krebs cycle is

QUESTION ID:90

Catabolite repression in bacteria is regulated by the concentration of

QUESTION ID:91

Phagocytosis was first described by

QUESTION ID:92

Which one of the following statements about batch culture of microbes is NOT correct?

QUESTION ID:93

Match the test in Group I with its application in Group II

Group I                                                                   Group II

P. Oakley-Fulthorpe test                                     1. IgM detection

Q. Limulus amoebocyte lysate test                   2. Determining antigen-antibody specificity

R. Weil-Felix reaction test                                  3. Endotoxin detection

S. Complement-fixation test                              4. Rickettsial infection diagnosis

QUESTION ID:94

Which one of the following is NOT correct about antibiotic resistance mechanism in microbes?

QUESTION ID:95

A suspension of photosynthetic green algae was illuminated in the presence of 14CO2 for few seconds. The first metabolite in the Calvin cycle to be radiolabeled will be

QUESTION ID:96

Determine the correctness or otherwise of the following Assertion [a] and the Reason [r].
Assertion [a]: Endospore can survive heat that would rapidly kill vegetative cells of the same species.
Reason [r]: In endospore, the protoplasm is reduced to minimum volume as a result of the accumulation of calcium-dipicolinic acid complexes and small acid-soluble spore proteins, which forms a cytoplasmic gel and a thick cortex.

QUESTION ID:97

Which one of the following conjugations will result in formation of merodiploids?

QUESTION ID:98

Which of the following genus is/are a spirochete(s)?

QUESTION ID:99

Which of the following is/are non-membrane bound inclusion bodies?

QUESTION ID:100

Which of the following antibiotics is/are isolated from Streptomyces spp.?

QUESTION ID:101

Which of the following statements about the primary and secondary adaptive immune responses to an antigen is/are correct?

QUESTION ID:102

The spontaneous, and induced mutations in bacteria can be distinguished by

QUESTION ID:103

During the exponential growth, it took 6 hours for the population of bacterial cells to increase from 2.5 × 106 to 5 × 108. The generation time of the bacterium, rounded off to the nearest integer, is ________ minutes.

QUESTION ID:104

Choose the correct group of fat soluble vitamins

QUESTION ID:105

The synthesis of thyroxine T4 in human body requires

QUESTION ID:106

Which among the followings is NOT an essential amino acid?

QUESTION ID:107

The time required for stipulated destruction of a microbial population at a given temperature is

QUESTION ID:108

Which among the following statements is NOT correct?

QUESTION ID:109

Calculate the efficiency in percent (rounded off to I decimal place) of an oil expeller which yields 37 kg oil containing 5% solid impurities from 100 kg mustard seeds. The oil content of the mustard seed is 38%.

QUESTION ID:110

Orange juice is packaged aseptically and stored under ambient conditions. The degradation of vitamin C in the juice occurs during storage and it follows first order reaction kinetics. The degradation rate constant is 5.2×103 day¹. The half-life of vitamin C in days is (in integer).

QUESTION ID:111

The weight of 10 kg dried cauliflower containing 5% moisture (wet basis) after rehydration is 60 kg. If the fresh cauliflower contained 87% moisture (wet basis). calculate the coefficient of rehydration (rounded off to 2 decimal places).

QUESTION ID:112

Some of the industrial products are produced by fermentation processes. Identify the correct pair of product and fermentative microorganism.

QUESTION ID:113

Choose the correct statement(s) about the enzyme and its application in food processing reaction.(MTA)

QUESTION ID:114

Identify the Gram +ve bacteria responsible for causing food borne diseases among the followings

QUESTION ID:115

Extrusion cooking is accomplished in four different stages, which are indicated as I, II, III and IV in the figure given below. Choose the correct option representing the name of each stage.

QUESTION ID:116

Match the method value used for measuring lipid characteristics in Column I with the corresponding properties indicated by them, in Column II.

Column I                                             Column II

P. Thiobarbituric acid test                1. Induction time

Q. Rancimat method                        2.  Degree of unsaturation

R. Peroxide value                              3.  Carbonyl content

S, Iodine value                                   4.  Hydroperoxide content

QUESTION ID:117

Match the peeling technique in Column I with the vegetable, for which it is used in industry, given in Column II.
Column I                                        Column II
P.Knife peeling                             1.Brinjal
Q.Abrasion peeling                      2. Tomato
 R. Flame peeling                         3.  Potato
 S. Flash peeling                           4.  Cucumber

QUESTION ID:118

Match the process in Column I with the related food component in Column II.
Column I                                  Column II
P. Caramelization                  1.Lipid
Q. Denaturation                     2.Sugar
R. Oxidation                           3. Pigment
S.  Bleaching                          4.  Enzyme

QUESTION ID:119

Identify the correct statement(s) related to grain polysaccharides among the followings.

QUESTION ID:120

A sample of glucose isomerase enzyme converts 15 umoles of substrate glucose into product fructose min¹ mL under standard assay conditions. The enzyme activity of the glucose isomerase in International Unit (IU) is (in integer)

QUESTION ID:121

If D10 for Salmonella in egg yolk is 0.75 kGy, calculate the radiation dose in kGy (rounded off to 2 decimal places) required for reducing the Salmonella count in egg yolk by 8 log cycles.

QUESTION ID:122

The average moisture binding energy of a textured protein product (TPP) at 8% moisture content (dry basis) is 3200 cal.mol'. If the water activity of the TPP at the above moisture content is 0.30 at 30 °C, the water activity of the sample at 45 °C is (rounded off to 2 decimal places). The value of Gas constant R = 1.987 cal.mol'.K'.