An infinite number of identical circular discs each of radius   tightly packed such that the centres of the discs are at integer values of coordinates x and y.  The ratio of the area of the uncovered patches to the total area is  :

In each of the following groups of words is a hidden number,  based on which you should arrange them in descending order. Pick the correct answer :
E.  Papers  I  xeroxed
F.  Wi - Fi  veteran
G.  Yourself  ourselves
H.  Breaks even

In each of the following groups of words is a hidden number, based on which you should arrange them in ascending order. Pick the right answer :
1.   Tinsel event
2.   Man in England
3.  Good height
4.   Last encounter

 Every month the price of a particular commodity falls in this order : 1024, 640, 250, ...........  What is the next value?

 A cart wheel rolls along a straight line. If the distance covered is equal to the diameter of the wheel,  what is the angle through which the wheel has turned?

Marks obtained by two students  S1 and  S2 in a four semester course are plotted in following graph  Which of the following statements is true?

A 16.2 m long wooden log has a uniform diameter of 2 m. To what length the log should be cut to obtain a piece of 22 m³ volume?

In the given figure, the area of the shaded region (in cm² ), is :

A granite block of  2 m x 5 m x 3 m size is cut into  5 cm  thick slabs of  2 m x 5 m size. These slabs are laid over a 2 m  wide pavement. What is the length of the pavement that can be covered with these slabs?

From the following statements
1. Hydrogen, Deuterium and Tritium differ in the number of protons.
2. Hydrogen, Deuterium and Tritium differ in the number of neutrons.
3. Both Deuterium and Tritium are radioactive and decay to Hydrogen and Deuterium, respectively.
4. Tritium is radioactive and decays to Helium.
5. Carbon-14 decays to Nitrogen-14.
6. Carbon-14 decays to Carbon-13.
Pick the combination with ALL correct statements. 

The random errors associated with the measurement of P and Q are 10% and 2%, respectively. What is the percentage random error in P/Q?

When Ramesh was at the age of 8 years, he hammered a nail into a large tree to mark his height. If the tree grows 2 cm/year, how much higher would the nail be after 6 years?

AB is the diameter of a circle. The chord CD is perpendicular to AB intersecting it at P. If CP = 2 and PB = 1, the radius of the circle is :

A shopkeeper purchases a product for Rs.100 and sells it making a profit of 10 %. The customer resells it to the same shopkeeper incurring a loss of 10 %. In these dealings the shopkeeper makes :

The product of the perimeter of a triangle, the radius of its in-circle, and a number gives the area of the triangle. The number is :

Starting from a point A you fly one mile south, then one mile east, then one mile north which brings you back to point A. Which of the following MUST be true ?

Three boxes are coloured red, blue and green and so are three balls. In how many ways can one put the balls one in each box such that no ball goes into the box of its own colour ?

There are two buckets A and B. Initially A has 2 litres of water and B is empty. At every hour 1 litre of water is transferred from A to B followed by returning 1/2 litre back to A from B half an hour later. The earliest A will get empty in :

Density of a rice grain is 1.5g/cc and bulk density of rice heap is 0.80 g/cc. If a 1 litre container is completely filled with rice, what will be the approximate volume of pore space in the container ?

What is the minimum number of moves required to transform figure 1 to figure 2 ? A move is defined as removing a coin and placing it such that it touches two other coins in its new position .

It takes 5 days for a steamboat to travel from A to B along a river. It takes 7 days to return from B to A. How many days will it take for a raft to drift from A to B (assuming all speed are constant) ?

How many times starting at 1: 00 pm would the minute and hour hands of a clock make an angle of 40° with each other in the next 6 hours ?

The graph shows cumulative frequency, percentage of research scholars and the number of papers published by them. Which of the following statements is true ?

The random errors associated with the measurement of P and Q are 10 % and 2%. respectively. What is the maximum percentage random error in P/Q ?

If a person travels x % faster than normal, he reaches y minutes earlier than normal. What is his normal time of travel ?

Pre - Ph.D exam score of 10 students are plotted against their M.Sc. marks. Which of the following is true ?

What is the average value of y for the range of x shown in the following plot ?

A fair die was thrown three times and the outcome was repeatedly six. If the die is thrown again what is the probability of getting six ?

What is the volume of soil in an open pit of size 2 m × 2 m × 10 cm ?

If a plant with green leaves is kept in a dark room with only green light on, which one of the following would we observe ?

The distance from city P to city Q is 27 km. A and B start walking from P towards Q at speeds of 5 km/hr and 7 km/hr, respectively. B reaches Q, returns immediately, and meets A at R. What is the distance between Pand R ? (assume all three cities to be in one straight line)

A floor of size 13 x 24 is to be paved using square tiles only. What is the smallest number of tiles needed to do this ?

Following statements are made about uncompetitive inhibition of an enzyme :
(a) Uncompetitive inhibitor binds to both free enzyme as well as an enzyme - substrate complex.
(b) Addition of uncompetitive inhibitor lowers the V_max of the reaction.
(c) Apparent K_M of the enzyme is lowered.
(d) Apparent K_M of the enzyme remains unchanged.
Which one of the following option represents the correct combination of the statments ?

Following are the pKa's of the ionizable groups in lysine :
pKa₁ = 2.16 (α – carboxylic group)
pKa₂ = 9.06(α – amino group)
pKa₃ = 10.54(ε – amino group)
Which one of the following options represents the pl of lysine ?

The enzyme alkaline phosphatase was tested for its catalytic activity using the substrate para-nitrophenylphosphate. The K_M obtained was 10 mM and V_max was 100 µ mol/min. Which one of the following options represents the initial velocity of the reaction at a substrate concentration of 10 mM?

How many hydrogen bonds involving the backbone CO and NH can be observed in an α - helix consisting, of 15 amino acid residues ?

Progression across Gl/S boundary followed by entry into S-phase is promoted by the activation of which one of the following protein complexes?

In eukaryotic cells, covalently attached lipids help to anchor some water soluble proteins to the plasma membrane. One group of cytosolic proteins are anchored to the cytosolic face of membrane by a fatty acyl group (e.g. myristate or palmitate). These groups are generally covalently attached to which amino acids present at the N-terminus of the polypeptide chain ?

The movement of proteins bigger than 50 kDa across the nuclear envelope requires :

Iron - sulphur clusters [Fe - S] are the key prosthetic groups that carry electrons in all of the below EXCEPT :

In bacteria many of the tRNA genes do not contain the CCA sequence found at the 3' end of tRNA. In this context which one of the following statements represents the correct explanation ?

Some cells possess peptides which contain D-form of amino acids. How do they arise ?

All of the following statements about bacterial transcription termination are true EXCEPT :

Which one of the following proteins is essential for both the initiation of DNA replication as well as the continued advance of the replication fork ?

Which one of the following combinations represents the major protein or protein complex involved in chromatin condensation in yeast and human, respectively ?

Which of the following is the causative agent of filariasis ?

The cytoplasmic domain of the receptor of which of the following proteins does NOT function as tyrosine kinase ?

Tumors are generally classified by :

A breakthrough in cancer therapy is expected where T - cells are taken from a patient are modified in the laboratory to attack cancer cells before re - infusion in the patient. These T - cells are called:

Which one of the following statements with respect to development in amphibians is correct ?

During normal development of sea urchin, b - catenin accumulates predominantly in the micromeres, which are fated to become endoderm and mesoderm. If GSK - 3 is blocked in the developing embryo:

In which of the following stages of Arabidopsis embryogenesis do the visible distinctions between the adaxial and abaxial tissues of the cotyledons become initially apparent ?

In a transplantation experiment, the area of presumptive ectoderm from an early frog gastrula was transplanted to a region of the newt gastrula destined to become parts of the mouth. The resulting salamander larvae had frog like mouth parts (frog tadpole suckers) instead of balancers as observed during development of wild type newt embryo. This is an example of :

Which of the following ' R ' gene products do not contain NBS - LRR domain ?

Photochemically generated ATP is consumed in which one of the following phases of Calvin- Benson cycle ?

Dirigent proteins predominantly play an important role in biosynthesis of :

Which one of the following is used in organification of tyrosine residues in thyroglobulin protein, during thyroid hormone biosynthesis ?

The dark current in retina is due to :

Which one of the following is not present in the filtration slit diaphragm ?

DNA was isolated from a strain in bacterium with genotype a⁺ b⁺ c⁺ d⁺ e⁺ and transformed into a bacterial strain a^– b^– c^–, d– e^–. The transformants were tested for the presence of the donated genes.
The cotransformed genes were found as follows: a⁺ and b⁺ ; c⁺ and e⁺ ; d⁺ and c⁺ ; b⁺ and d⁺; What is the order of genes on the bacterial chromosome ?

A fly with apricot coloured eye was crossed with a sepia eyed fly of opposite sex. In F1 all flies were wild type. The genes responsible for the two phenotypes were :

Human polydactyly traits having extra fingers or toes are caused by a dominant allele. In a screening it was found that out of 42 individuals having an allele for polydactyly, only 38 of them were polydactylus. Which of the following is the correct interpretation of the observation ?

The basic difference between direct repair and base excision repair is :

Eukaryotes are classified into 5 - 6 super groups based on phylogenomic studies. Which one of the following statements about eurkaryotic supergroups is FALSE ?

What is the pattern of cleavage observed in mammals ?

Which of the following combinations would best characterize the dominant phase of the life cycle of a pteridophyte ?

Which one of the following gases is present in the stratosphere at a concentration higher than its concentration in troposphere ?

The graph below shows the change in the size of four populations (a) – (d) over time.

Which among the four populations (a), (b), (c) and (d) would have the lowest intrinsic rate of population growth (r) ?

Consider the following ecosystems.
(a) Tropical rain forests
(b) Open ocean
(c) Algal beds and Coral reefs
(d) Marshes and Swamps
Which one of the following options represents these ecosystems in an increasing order of their contribution to annual world net primary production ?

Historical frequencies of fires in an area can be determined by :

Given below are statements on 'living fossils'.
Select the correct statements.

Mimicry where deceptiveness of the mimic's signal is high and fitness consequences signaled to the receiver by the mimic is also high (& negative) is :

Consider the following four geological periods.
(a) Quaternary
(b) Cretaceous
(c) Jurassic
(d) Cambrian
Which one of the following options represents the correct arrangement of these geological periods from earliest to recent :

Select the correct statement related to phylogeny of primates

Which one of the following combinations of terms is matched INCORRECTLY ?

Which one of the following statements is correct ?

Which one of the following regions of the target gene is NOT used for making an RNAi construct to knock down its expression ?

Which one of the following options represents a combination of terms that are matched INCORRECTLY ?

For a nuclear spin of spin quantum no. , precessing in a magnetic field at a Larmor frequency of 300 MHz, the wavelength of incident radiation required to excite the nuclear spins must be approximately.

Widal test, a widely used serological test for enteric fever, is a type of :

Fluorescence microscope that requires photo - activatable probes to obtain super - resolution is :

A protein solution (0.2 ml) of unknown concentration was diluted with 0.8 ml of water. To 0.5 ml of this diluted solution 4.5 ml of biuret reagent was added and the colour allowed to develop. The absorbance of this mixture taken in a test tube of 1 cm diameter at 540 nm was observed to be 0.20 .0 .5 ml of BSA (4 mg/ml) solution plus 4.5 ml of biuret gave an absorbance of 0.20 when measured as above. What is the protein concentration (mg/ ml) in the undiluted unkown solution ?

A schematic of a metabolic pathway is shown below :

Under which of the following conditions would stoichiometric amounts of end products K and L be obtained if a concerted feedback inhibition mechanism were in operation ?

The following statements are being made to define the Michaelis constant (K_M). It is :
(a) Independent of enzyme concentration (E) and substrate concentration [S]
(b) Equal to the dissociation constant when the [ES] complex dissociates more rapidly than product formation
(c) Equal to the dissociation constant when product formation is more rapid than [ES] complex dissociation
(d) An intrinsic property of an enzyme and does not depends on pH, temperature and ionic strength
Which one of the following combination of statements is correct ?

The table below lists the biochemical characteristics of proteins and experimental procedures used to determine them. Match the characteristics with the experimental procedure.
 

	List - I		List - II
	(Biochemical Characteristics)		(Experimental Procedure)
(a)	B - dimensional struchure	(i)	Nuclear magnetic resonance
(b)	Ionic Charge	(ii)	Isoelectric focusing
(c)	Binding	(iii)	Affinity specificity Chromatography
(d)	Molecular size	(iv)	Ultracentrifugation

Which one of the following matches is correct ?

A circular dichroism spectrum in the far - UV region informs on the kind and content of secondary structures in a protein. Near - UV and tryptophan emission spectra inform on the tertiary structure. Shown in the panels above are (A) intrinsic fluorescence emission spectra of protein ' X ', (B) Far - UV CD spectra of protein ' X ', (C) Near - UV CD spectra of protein ' X ' recorded under different conditions.
Curves represent the spectra of protein ' X ' at pH 7.0 (black), pH 3.0 (green), and pH 7.0 in the presence of 6.0 M guanidine hydrochloride (red). What does the experiment report ?

The pl of four proteins (A, B, C, D) are shown in the table below :

To purify ' D ' from a mixture of these four proteins in a single step, using ion - exchange chromatography, what combination of buffer pH and ion - exchange resin would you select ?

The curve B in the figure below shows the oxygen dissociation profile at physiological concentration of CO₂ and pH 7.

An increase in pH would lead to oxygen dissociation profile indicated by :

Following statements were made about chromosome cohesion during mitosis and meiosis.
(a) Though cohesin is important for pairwise alignment of the chromosomes on the mitotic spindle, it is not important for the generation of tension across the centromere.
(b) Cohesin binds to the chromosome even before the initiation of S - phase.
(c) In fission yeast, centromere specific localization of Moal and Rec8 regulates the orientation of kinetochores at meiosis - I.
(d) Cohesin exhibits uniform distribution/ localization pattern across the chromosomal length.
(e) Polo/Cdc5 is a positive regulator of Separase, an endopeptidase that facilitates opening of the cohesin ring.
Which one of the following combination contains all correct statements ?

Which one of the following is valid with respect to, one step growth experiment developed by Ellis and Delbruck in 1939 ?

Given below are a few statements about nuclear transport.
(a) RanGTP levels are higher in the nucleus than the cytoplasm.
(b) Nuclear import receptors can shuttle between the nucleus and cytoplasm.
(c) NTF2 transports RanGDP into the cytosol. (d) Export of mRNA is not directly dependent on Ran.
(e) tRNA and miRNA export is mediated by exportins.
Which one of the following combination contains all correct statements ?

During cytokinesis, a sinall GTPase, RhoA, localizes to the equatorial membrane above the spindle midzone. The localization/activity of RhoA is potentially modulated by :
(a) RhoGEF Ect2
(b) Aurora B kinase
(c) PLK1 kinase
(d) MKLP1 kinesin
(e) ATM and ATR
Which one of the following combination contains all correct statements ?

Cellular actin levels can be as high as 100 – 400 µM. Of this, unpolymerized actin concentration can be as much as 50 – 200 m M. However, the critical concentration for actin polymerization in - vitro is about 0.2µ M. Some of the following proteins inhibit polymerization of actin in cells.
(a) Thymosin - b4
(b) Capping protein CapZ
(c) Tropomodulin
(d) XMAP 215
Which one of the following options lists all inhibitors ?

To delineate the steps in endoplasmic reticulum (ER) transport, a Ph.D student homogenized pancreatic acinar cells to isolate microsomes, which retain most of the biochemical properties of the ER. For this experiment, the student has planned a number of controls as mentioned below.
(a) Treat one set of microsomes first with detergent and then with protease.
(b) Treat one set of microsomes with protease only.
(c) Treat one set of microsomes with micrococcal nuclease.
(d) Treat one set of microsomes with detergent only.
Select the option that represents the best combination of the controls.

Following statements were made about imprinting in the human genome. (a) Imprinting control centre (IC) harbors part of the SNRPN gene. (b) Imprinting of genes in an individual cannot be tissue specific. (c) Sperms and eggs exhibit identical pattern of genome methylation, except in the sex chromosomes. (d) At imprinted loci, expression depends on the parental origin. Select the option with all the correct statements.

Mitochondrial protein synthesis is of prokaryotic origin. Following statements are being made about the ribosomes from bacteria and mitochondria :
(a) The bacterial ribosome consists of small and large subunits of 30S and 50S respectively, whereas in mitochondria of mammals these subunits are of 28S and 39S
(b) In the bacterial ribosomes the RNA: protein ratio is about 2 : 1 whereas in mitochondria ribosomes this ratio is usually 1 : 2
(c) Both the bacterial and mitochondrial ribosomes consist of 30S and 50S subunits
(d) Both the bacterial and mitochondrial ribosomes consist of RNA and protein in the ratio of 1 : 1
Choose the option that represents all correct statements.

Given below are a few statements about the l infection cycle :
(a) Competition between cI and cII gene products determines the establishment of lysogeny versus lysis.
(b) cI binds OR1 first while cro binds to OR 3 first
(c) Cro binding to OR represses cI transcription
(d) Rich medium favours lytic cycle because cII is protected from cellular proteases
Which one of the following options represents all correct statements ?

Reproduction of ϕ × 174, a single stranded DNA phage involves several steps. A few statements are given below to explain the mechanism .
(a) The single stranded ϕ × 174 DNA is converted into a double - stranded replicative form (RF)
(b) Replication of double stranded replicative form results in the production of single stranded phages, about 50 % of which are + ve sense phages and the remaining are – ve sense phages
(c) Replication of the double stranded replicative form results in the production of only – ve sense phages
(d) Replication of the double stranded replicative form results in the production of only + ve sense phages
Choose the option that correctly describes the process:

Which one of the following schematics depicts the potential relationship among the subunits IIo, IIa, and IIb of RNA polymerase II ?

The following statements are made with reference to DNA replication :
(a) Camptothecin causes intra-strand and inter-strand crosslinks in DNA, leading to stalling of replication forks.
(b) Prevention of reinitiation of DNA replication during the same cell cycle is mediated by regulating the loading of the initiator complex ORC.
(c) A glu → ala mutation in the nucleotide building pocket of DNA polymerase III could lead to the incorporation of ribonucleotides in the extending DNA chain.
(d) A mutation in the gene encoding Topoisomerase II could lead to entanglement of DNA daughter strands during replication.
Which one of the following options represents all correct statements?