When CO₂ concentration in blood increases breathing becomes

If you are provided with root-tips of onion in your class and are asked to count the chromosomes, which of the following stages can you most conveniently look into?

In C₃ plants, the first stable product of photosynthesis during the dark reaction is

Plants adapted to low light intensity have

In glycolysis, during oxidation electrons are removed by

Cell elongation in internodal regions of the green plants takes place due to

One set of the plant was grown at 12 hours day and 12 hours night period cycles and it flowered while in the other set night phase was interrupted by flash of light and it did not produce flower. Under which one of the following categories will you place this plant?

Blood analysis of a patient reveals an unusually high quantity of carboxyhaemoglobin content. Which of the following conclusions is most likely to be correct?
The patient has been inhaling polluted air containing unusually high content of

Which one of the following precedes reformation of the nuclear envelope during M phase of the cell cycle?

You are required to draw blood from a patient and to keep it in a test tube for analysis of blood corpuscles and plasma. You are also provided with the following four types of test tubes.
which of these you will not use for the purpose.

In the resting state of the neural membrane, diffusion due to concentration gradients, if allowed, would drive

Injury to vagus nerve in humans is not likely to affect

Which one of the following pairs correctly matches a hormone with a disease resulting from its deficiency?

Which one of the following hormones is modified amino acid?

Chemically hormones are

Anthesis is a phenomenon which refers to

When a diploid female plant is crossed with a tetraploid male, the ploidy of endosperm cells in the resulting seed is

An ovule which becomes curved so that the nucellus and embryo sac lie at right angles to the funicle is

Diversification in plant life appeared

Which of the following statements is not true for retroviruses?

Viruses that infect bacteria multiply and cause their lysis, are called

Phenetic classification of organisms is based on

A free living nitrogen-fixing cyanobacterium which can also symbiotic association with the water ferm Azolla is

During replication of a bacterial chromosome DNA synthesis starts from a replication origin site and

Lichens are well known combination of an alga and a fungus where fungus has

Which of the following hormones is not a secretion product of human placenta -

Angiosperms have dominated the land flora primarily because of their

In Arthropoda, hend and thorax are often used to form cephalothorax, but in which one of the following classes, is the body divided into head thorax and abdomen?

The animals with bilateral symmetry in young stage, and radial pentamerous symmetry in the adult stage, belong to the Phylum

Presence of gills in the tadpole of frog indicates that

Uricotelism is found in

When a fresh-water protozoan possessing a contractile vacuole, is placed in a glass containing marrine water, the vacuole will

One of the following is a very unique feature of the mammalian body

Edible part of mango is

Which one of the following enzymes, is copper necessarily associated as an activator?

In the somatic cell cycle

Which of the following is expected to have the highest value (gm/m²/yr) in a grassland ecosystem ?

Which one of the following pairs is not correctly matched ?

Restriction endonucleases :-

In transgenics expression of transgene in target tissue is determined by :-

DNA fingerprinting refers to :-

ELISA is used to detect viruses, wherethe key reagent is :-

The Ti plasmid is often used for making transgenic plants. This plasmid is found in

Certain characteristic demographic features of developing countries are -

What is a keystone species ?

The maximum growth rate occurs in :-

In which of the following pairs is the specific characteristic of a soil not correctly matched ?

In which one of the following habitats does the diurnal temperature of soil surface vary most ?

The most thoroughly studied of the known bacteria-plant interactions is the :-

An ecosystem which can be easily damaged but can recover after some time if damaging effect stops will be having -

In your opinion, which is the most effective way to conserve the plant diversity of an area ?

In a longitudinal section of a root, starting from the tip upward, the four zones occur in the following order :-

Mast cells of connective tissue contain -

In chloroplasts, chlorophyll is present in the :-

The telomeres of eukaryotic chromosomes consist of short sequences of

A major component of gobar gas is

In a mutational event, when adenine is replaced by guanine, it is a case of -

Ovulation in the human female normally takes place during the menstrual cycle -

In a plant, red fruit (R) is dominant over yellow fruit (r) and tallness (T) is dominant over shortness (t). If a plant with RRTt genotype is crossed with a plant that is rrtt

Lack of independent assortment of two genes A and B in fruit fly Drosophila is due to :-

A male human is heterozygous for autosomal genes A and B and is also hemizygous for hemophilic gene h. What proportion of his sperms will be abh :-

One of the parents of a cross has a mutation in its mitochondria. In that cross, that parent is taken as a male. During segregation of F₂ progenies that mutation is found in -

A normal woman, whose father was colour-blind is married to a normal man. The sons would be :-

The recessive genes located on X-chromosomes in humans are always-

During transcription, if the nucleotide sequence of the DNA strand that is being coded is ATACG, then the nucleotide sequence in the mRNA would be -

Which form of RNA has a structure resembling clover leaf ?

After a mutation at a genetic locus the character of an organism changes due to the change in :-

The following ratio is generally constant for a given species :-

Age of fossils in the past was generally determined by radio-carbon method and other methods involving radioactive elements found in the rocks. More precise methods, which were used recently and led to the revision of the evolutionary periods for different groups of organisms includes -

What kind of evidence suggested that man is more closely related with chimpanzee than with other hominoid apes ?

Which one of the following is living fossil ?

Diversification in plant life appeared

According to oparin, which one of the following was not present in the primitive atmosphere of the earth ?

Which one of the following is not correctly matched ?

Dough kept overnight in warm weather becomes soft and spongy because of :-

CN^$$-$$ is a strong field ligand. This is due to the fact that

In an octahedral structure, the pair of $$d$$ orbitals involved in d²sp³ hybridisation is

Which of the following does not have a metal carbon bond?

Which of the following is considered to be an anticancer species?

Among [Ni(CO)₄], [Ni(CN)₄]^2$$-$$, [NiCl₄]^2$$-$$ species, the hybridisation states at the Ni atom are, respectively
[Atomic number of Ni = 28]

The rate of a first order reaction is 1.5 $$ \times $$ 10^$$-$$2 mol L^$$-$$1 min^$$-$$1 at 0.5 M concentration of the reactant. The half-life of the reaction is

In a reaction of aniline a coloured product C was obtained.

The structure of C would be

The correct statement in respect of protein haemoglobin is that it

Number of chiral carbons in $$\beta $$-$$D$$-(+) glucose is

A sequence of how many nucleotides in messenger RNA makes a codon for an amino acid?

The hormone that helps in the conversion of glucose to glycogen is

The helical structure of protein is stablised by

Which of the following structures represents the peptide chain?

The standard e.m.f. of a galvanic cell involving cell reaction with n = 2 is found to be 0.295 V at 25^oC. The equilibrium constant of the reaction would be

Which one of the following can be oxidised to the corresponding carbonyl compound?

Which one of the following statements about the zeolite is false?

Among K, Ca, Fe and Zn, the element which can from more than one binary compound with chlorine is

lanthanoids are

Among the following series of transition metal ions, the one where all metal ions have 3d² electronic configuration is
[At. Nos. Ti = 22, V = 23, Cr = 24, Mn = 25]

The radioactive isotope $${}_{27}^{60}$$Co which is used in the treatment of cancer can be made by (n.p) reaction. For this reaction the tarfet nucleus is

Considering H₂O as a weak field ligand, the number of unpaired electrons in [Mn(H₂O)₆]²⁺ will be (atomic number of Mn = 25)

Which of the following coordination compounds would exhibit optical isomerism?

The work done during the expansion of a gas from a volume of 4 dm³ to 6 dm³ against a constant external pressure of 3 atm is (1 L atm = 101.32 J)

The maximum number of molecules is present in

The frequency of radiation emitted when the electron falls from n = 4 to n = 1 in hydrogen atom will be (Given ionization energy of H = 2.18 $$ \times $$ 10^$$-$$18 J atom^$$-$$1 and h = 6.625 $$ \times $$ 10^$$-$$34 J s)

Ionic radii are

In a regular octahedral molecule, MX₆ the number of X $$-$$ M $$-$$ X bonds at 180^o is

Among the following, the pair in which the two species are not isostructural is

H₂O is dipolar, whereas BeF₂ is not. It is because

In BrF₃ molecule, the lone pairs occupy equatorial positions to minimize

If the bond energies of H $$-$$ H, Br $$-$$ Br, and H $$-$$ Br are 433, 192 and 364 kJ mol^$$-$$1 respectively, the $$\Delta $$H^o for the reaction

H_2(g) + Br_2(g) $$ \to $$ 2HBr_(g) is

Standard enthalpy and standard entropy changes for the oxidation of ammonia at 298 K are $$-$$ 382.64 kJ mol^$$-$$1 and $$-$$ 145.6 kJ mol^$$-$$1, respectively. Standard Gibb's energy change for the same reaction at 298 K is

Considering entropy (S) as a thermodynamic parameter, the criterion for the spontaneity of any process is

The solubility product of a sparingly soluble salt AX₂ is 3.2 $$ \times $$ 10^$$-$$11. Its solubility (in moles/L) is

The rapid change of pH near the stoichiometric point of an acid-base titration is the basis of indicator detection. pH of the solution is related to ratio of the concentrations of the conjugate acid (HIn) and base (In^$$-$$) forms of the indicator by the expression

The molecular formula of diphenyl methane,



How many structural isomers are possible when one of the hydrogen is replaced by a chlorine atom ?

The $$-$$ OH group of an alcohol or the $$-$$ COOH group of a carboxylic acid can be replaced by $$-$$ Cl using

Using anhydrous AlCl₃ as catalyst, which one of the following reactions produces ethylbenzene (PhEt)?

Reaction of HBr with propene in the presence of peroxide gives

Which of the following is least reactive in a nucleophilic sibstitution reaction?

Which one of the following will not form a yellow precipitate on heating with an alkaline solution of iodine?

Which is the best description of the behaviour of bromine in the reaction given below?
H₂O + Br₂ $$ \to $$ HOBr + HBr

The refractive index of the material of a prism is $$\sqrt 2 $$ and its refracting angle is 30^o. One of the refracting surfaces of the prism is made a mirror inwards. A beam of monochromatic light entering the prism from the other face with retrace its path after reflection from the mirrored surface if its angle of incidence on the prism is

Five equal resistances each of resistances R are connected as shown in the figure. A battery of V volts is connected between A and B. The current flowing in AFCEB will be

when three identical bulbs of 60 watt, 200 volt rating are connected in series to a 200 volt supply, the power drawn by them will be

A 6 volt battery is connected to the terminals of a three metre long wire of uniform thickness and resistance of 100 ohm. The difference of potential between two points on the wire separated by a distance of 50 cm will be

In India electricity is supplied for domestic use at 220 V. It is supplied at 110 V in USA. If the resistance of a 60 W bulb for use in India is R, the resistance of a 60 W bulb for use in USA will be

Resistance n, each of r ohm, when connected in parallel give an equivalent resistance of R ohm. If these resistances were connected in series, the combination would have a resistance in ohms, equal to

The electric resistance of a certain wire of iron is R. If its length and radius are both doubled, then

A galvanometer of 50 ohm resistance has 25 divisions. A current of 4 $$ \times $$ 10^$$-$$4 ampere gives a deflection of one division. To convert this galvanometer into a voltmeter having a range of 25 volts, it should be connected with a resistance of

To convert a galvanometer into a voltmeter one should connect a

A coil of 40 henry inductance is connected in series with a resistance of 8 ohm and the combination is joined to the terminals of a 2 volt battery. The time constant of the circuit is

The magnetic flux through a circuit of resistance R changes by an amount $$\Delta $$$$\phi $$ in a time $$\Delta $$t. Then the total quantity of electric charge Q that passes any point in the circuit during the time $$\Delta $$t is represented by

A telescope has an objective lens of 10 cm diameter and is situated at a distance of one kilometer from two objects. The minimum distance between these two objects, which can be resolved by the telescope, when the mean wavelength of light is 5000 $$\mathop A\limits^ \circ $$, is of the order of

An electric dipole has the magnitude of its charge as q and its dipole moment is p. It is placed in a uniform electric field E. If its dipole moment is along the direction of the field, the force on it and its potential energy are respectively

A beam of light composed of red and green ray is incident obliquely at a point on the face of rectangular glass slab. When coming out on the opposite parallel face, the red green ray emerge from

According to Einstein's photoelectric equation, the graph between the kinetic energy of photoelectrons ejected and the frequency of incident radiation is

If M(A; Z), M_p and M_n denote the masses of the nucleus $${}_Z^AX,$$ proton and neutron respectively in units of u (1 u = 931.5 MeV/c²) and BE represents its bonding energy in MeV, then

The Bohr model of atoms

If in a nuclear fusion process the masses of the fusing nuclei be m₁ and m₂ and the mass of the resultant nucleus be m₃, then

In semiconductors at a room temperature

The peak voltage in the output of a half wave diode rectifier fed with a sinusoidal signal without filter is 10 V. The d.c. component of the output voltage is

The output of OR gate is 1

A round disc of moment of inertia $$I$$₂ about its axis perpendicular to its plane and passing through its centre is placed over another disc of moment of inertia $$I$$₁ rotating with an angular velocity $$\omega $$ about the same axis. The final angular velocity of the combination of discs is

The unit of permittyvity of free space, $${\varepsilon _0}$$, is

If $$\left| {\overrightarrow A \times \overrightarrow B } \right| = \sqrt 3 \overrightarrow A .\overrightarrow B $$ then the value of $$\left| {\overrightarrow A + \overrightarrow B } \right|$$ is

A block of mass m is placed on a smooth wedge of inclination $$\theta $$. The whole system is accelerated horizontally so that the block does not slip on the wedge. The force exerted by the wedge on the block will be (g is acceleration due to gravity)

The coefficient of static friction, $$\mu $$_s, between block A of mass 2 kg and the table as shown in the figure is 0.2. What would be the maximum mass value of block B so that the two blocks do not move? The string and the pulley are assumed to be smooth and massless. (g = 10 m/s²)

A ball of mass 2 kg and another of mass 4 kg are dropped together from a 60 feet ball building. After a fall of 30 feet each towards earth, their respective kinetic energies will be in the ratio of

A particle of mass m₁ is moving with a velocity v₁ and another particle of mass m₂ is moving with a velocity v₂. Both of them have the same momentum but their different kinetic energies are E₁ and E₂ respectively. If m₁ > m₂ then :

A mass of 0.5 kg moving with a speed of 1.5 m/s on horizontal smooth surface, collides with a nearly weightless spring of force constant k = 50 N/m. The maximum compression of the spring would be

Three particles, each of mass m gram, are situated at the vertices of an equilateral triangle ABC of side $$l$$ cm (as shown in the figure). The moment of inertia of the system about a line AX perpendicular to AB and in the plane of ABC, in gram-cm² units will be

A wheel having moment of inertia 2 kg m² about its vertical axis, rotates at the rate of 60 rpm about this axis. The torque which can stop the wheel's rotation in one minute would be

Consider a system of two particles having masses m₁ and m₂. If the particle of mass m₁ is pushed towards the mass centre of particles through a distance d. by what distance would be particle of mass m₂ move so as to keep the mass centre of particles at the original position?

Of the diodes shown in the following diagrams, which one is reverse biased ?

The ratio of the radii of gyration of a circular disc about a tangential axis in the plane of the disc and of a circular ring of the same radius about a tangential axes in the plane of the ring is

The density of a newly discovered planet is twice that of earth. The acceleration due to gravity at the surface of the planet is equal to that at the surface of the earth. If the radius of the earth is R, the radius of the planet would be

If $$\lambda $$_m denotes the wavelength at which the radioactive amission from a black body at a temperature TK is maximum, then

The equation of state for 5 g of oxygen at a pressure P and temperature T, when occupying a volume V, will be
(where R is the gas constant)

One mole of an ideal gas at an initial temperature of T K does 6R joule of work adiabatically. If the ratio of specific heats of this gas at constant pressure and at constant volume is 5/3, the final temperature of gas will be

Two springs of spring constants k₁ and k₂ are joined in series. The effective spring constant of the combination is given by

A particle executing simple harmonic motion of amplitude 5 cm has maximum speed of 31.4 cm/s. The frequency of its oscillation is

The phase difference between two waves. represented by
y₁ = 10^$$-$$6 sin[100t + (x/50) + 0.5] m
y₂ = 10^$$-$$6 cos[100t + (x/50)] m,
where x is expressed in metres and t is exressed in secondss, is approximately.

A bullet of mass 2 g is having a charge of 2 $$\mu $$C. Through what potential difference must it be accelerated, starting from rst, to acquire a speed of 10 m/s ?

The dimensions of universal gravitational constant are