Plants deficient of element zinc, show its effect on the biosynthesis of plant growth hormone

The major role of minor elements inside living organisms is to act as

Which element is located at the centre of the porphyrin ring in chlorophyll?

In sugarcane plant ¹⁴CO₂ is fixed to malic acid, in which the enzyme that fixes CO₂ is

Stomata of CAM plants

Which one of the following is wrong in relation to photorespiration?

Which fractions of the visible spectrum of solar radiations are primarily absorbed by carotenoids of the higher plants?

Which one of the following concerns photophosphorylation?

In alcohol fermentation

In which one of the following do the two names refer to one and same thing?

Juicy hair-like structures observed in the lemon fruit develop from

Differentiation of shoot is controlled by

Nicotiana sylvestris flowers only during long days and N.tabacum flowers only during short days. If raised in the laboratory under different photoperiods, they can be induced to flower at the same time and can be cross-fertilized to produce self-fertile offspring. What is the best reason for considering N.sylvestris and N.tabacum to be separate species?

The cardiac pacemaker in a patient fails to function normally. The doctors find that an artificial pacemaker is to be grafted in him. It is likely that it will be grafted at the site of

Bundle of His is a network of

In the ABO system of blood groups, if both antigens are present but no antibody, the blood group of the individual would be

If Henle's loop were absent from mammalian nephron, which one of the following is to be expected?

What used to be described as Nissl's granules in a nerve cell are now identified as

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

In a flowering plant, archesporium gives rise to

Which one of the following pairs of plants are not seed producers?

Species are considered as

Biosystematics aims at

Phenetic classification of organisms is based on

Chromosomes in a bactertial cell can be 1 $$-$$ 3 in number and

Tobacco mosaic virus is a tubular filament of size

Which one of the following statements about viruses is correct?

Viruses are no more ''alive'' than isolated chromosomes because

In which kingdom would you classify the archaea and nitrogen-fixing organisms, if the five-kingdom system of classification is used?

During embryonic development, the establishment of polarity along anterior/posterior, dorsal/ventral or medial/lateral axis is called : -

Sexual reproduction in Spirogyra is an advanced feature because it shows

Plants reproducing by spores such as mosses and ferns are grouped under the general term

Which one pair of examples will correctly represent the grouping spermatophyta according to one of the schemes of classifying plants?

Bartholin's glands are situated

The chief advantage of encystment of an Amoeba is

Systemic heart refers to

Sycon belongs to a group of animals, which are best described as

During the life-cycle, Fasciola hepatica (liver fluke) infects its intermediate host and primary host at the following larval stages respectively

Ommatidia serve the purpose of photoreception in

Which one of the following is a matching pair of an animal and a certain phenomenon it exhibits?

Given below are four matchings of an animal and its kind of respiratory organ :
(A)  Silver fish      $$-$$      Trachea
(B)  Scorpion      $$-$$      Book lung
(C)  Sea squirt      $$-$$      Pharyngeal slits
(D)  Dolphin      $$-$$      Skin
The correct matchings are

Which endangered animal is the source of the world's finest, lightest, warmest and most expensive wool - the shahtoosh ?

Carcinoma refers to : -

Short-lived immunity acquired from mother to foetus across placenta or through mother's milk to the infant is categorised as :-

Christmas disease is another name for : -

Which of the following plants are used as green manure in crop fields and in sandy soils ?

Maximum application of animal cell culture technology today is in the production of : -

During anaerobic digestion of organic waste, such as in producing biogas, which one of the following is left undergraded : -

In recent years, DNA sequences (nucleotide sequence) of mt-DNA and Y chromosomes were considered for the study of human evolution, because : -

Which one of the following bacteria has found extensive use in genetic engineering work in plants ?

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

Mycorrhiza is an example of :-

Which group of vertebrates comprises the highest number of endangered species ?

Which one of the following describes correctly the homologous structures ?

The apical meristem of the root is present

In which one of the following nitrogen is not a constituent ?

The aleurone layer in maize grain is specially rich in :-

Chlorenchyma is known to develop in the : -

Diffuse porous wood is characteristics of those plants which are growing in : -

The cells of the quiescent centre are characterised by : -

Which one of the following contains the largest quantity of extracellular material ?

Cellular totipotency is demonstrated by :-

Coconut milk factor is

What does "lac" refer to in what we call the lac operon ?

Test tube baby means a baby born when

Two opposite forces operate in the growth and development of every population. One of them relates to the ability to reproduce at a given rate. The force opposing it is called : -

Which one of the following traits of garden pea studied by Mendel was a recessive feature ?

The genes controlling the seven pea characters studied by Mendel are now known to be located on how many different chromosomes ?

Two crosses between the same pair of genotypes or phenotypes in which the sources of the gametes are reversed in one cross, is known as : -

Pattern baldness, moustaches and beard in human males are examples of : -

In Drosophila, the sex is determined by : -

Down's syndrome is caused by an extra copy of chromosome number 21. What percentage of offspring produced by an affected mother and a normal father would be affected by this disorder ?

Which one of the following conditions though harmful in itself, is also a potential saviour from a mosquito borne infectious disease ?

During transcription, the DNA site at which RNA polymerase binds is called :-

In the genetic code dictionary, how many codons are used to code for all the 20 essential amino acids : -

During translation initiation in prokaryotes, a GTP molecule is needed in : -

What would happen if in a gene encoding a polypeptide of 50 amino acids, 25th codon (UAU) is mutated to UAA ?

Which one of the following triplet codes, is correctly matched with its specificity for an amino acid in protein synthesis or as 'start' or 'stop' codon ?

Degeneration of a genetic code is attributed to the : -

Convergent evolution is illustrated by : -

Which one of the following sequences was proposed by Darwin and Wallace for organic evolution ?

Random genetic drift in a population probably results from

Industrial melanism is an example of : -

In a random mating population in equilibrium, which of the following brings about a change in gene frequency in a non-directional manner : -

Darwin in his 'Natural Selection Theory' did not believe in any role of which one of the following in organic evolution ?

Which one of the following is categorised under living fossils ?

The radioistope, tritium ($${}_1^3$$H) has a half-life of 12.3 years. If the initial amount of tritium is 32 mg, how many milligrams of it would remain after 49.2 years?

The number of unpaired electrons in the complex ion [CoF₆]^3$$-$$ is
(Atomic no. : Co = 27)

Among the following which is not the $$\pi $$-bonded organometallic compound?

The correct order of ionic radii of Y³⁺, La³⁺, Eu³⁺ and Lu³⁺ is
(Atomic nos. Y = 39, La = 57, Eu = 63, Lu = 71)

In this reaction :
CH₃CHO + HCN $$ \to $$ CH₃CH(OH)CN
           $$\buildrel {HOH} \over \longrightarrow $$ CH₃CH(OH)COOH
an asymmetric centre is generated. The acid obtained would be

$$A$$ and $$B$$ in the following reactions are :

When $$m$$-chlorobenzaldehyde is treated with 50% KOH solution, the product(s) obtained is (are)

In a set of the given reactions, acetic acid yielded a product C.

Product $$C$$ would be

The final product C, obtained in this reaction

would be

Glycolysis is

Vitamin B₁₂ contains

Chargaff's rule states that in an organism

Phospholipids are esters of glycerol with

The e.m.f. of a Daniell cell at 298 K is E₁.

When the concentration of ZnSO₄ is 1.0 M and that of CuSO₄ is 0.01 M, the e.m.f. changed to E₂. What is the relationship between E₁ and E₂?

On the basis of the information available from the reaction,

4/3Al + O₂ $$ \to $$ 2/3Al₂O₃,   $$\Delta $$G = $$-$$ 827 kJ mol^$$-$$1 of O₂,

the minimum e.m.f. required to carry out an electrolysis of Al₂O₃ is
(F = 96500 C mol^$$-$$1)

The temperature dependence of rate constant (k) of a chemical reaction is written in terms of Arrhenius equation, $$k = A \cdot {e^{ - E{}^ * /RT}}$$. Activation energy (E^{$$ * $$}) of the reaction can be calculated by plotting

If the rate of the reaction is equal to the rate constant, the order of the reaction is

The reaction A $$ \to $$ B follows first order kinetics. The time taken for 0.8 mole of A to produce 0.6 mole of B is 1 hour. What is the time taken for conversion of 0.9 mole of A to produce 0.675 mole of B?

The activation energy for a simple chemical reaction A $$\rightleftharpoons$$ B is E_$$a$$ in forward direction.
The activation energy for reverse reaction

Which one of the following compounds is not a protonic acid?

Which one of the following characteristics of the transition metals is associated with their catalytic activity?

The basic character of the transition metal monoxides follows the order
(Atomic no's. Ti = 22, V = 23, Cr = 24, Fe = 26)

The equilibrium constants of the following are

N₂ + 3H₂ $$\rightleftharpoons$$ 2NH₃;     K₁

N₂ + O₂ $$\rightleftharpoons$$ 2NO;     K₂

H₂ + $${1 \over 2}$$O₂ $$\rightleftharpoons$$ H₂O;     K₃

The equilibrium constant (K) of the reaction :

2NH₃ + $${5 \over 2}$$ O₂ $$\rightleftharpoons$$ 2NO + 3H₂O will be

The velocity of Planck's constant is 6.63 $$ \times $$ 10^$$-$$34 J s.

The velocity of light is 3.0 $$ \times $$ 10⁸ m s^$$-$$1. Which value is closest to the wavelength in nanometers of a quantum of light with frequency of 8 $$ \times $$ 10¹⁵ s^$$-$$1 ?

The ions O^2$$-$$, F^$$-$$, Na⁺, Mg²⁺ and Al³⁺ are isoelectronic. Their ionic radii show

Which one of the following statements is not correct for sigma- and pi- bonds formed between two carbon atoms?

For the reaction,
C₃H_8(g) + 5O_2(g) $$ \to $$ 3CO₂(g) + 4H₂O_(l)
at constant temperature, $$\Delta $$H $$-$$ $$\Delta $$E is

The densities of graphite and diamond at 298 K are 2.25 and 3.31 g cm^$$-$$3, respectively. If the standard free energy difference $$\left( {\Delta {G^o}} \right)$$ is equal to 1895 J mol^$$-$$1, the pressure at which graphite will be transformed into diamond at 298 K is

Formation of solution from two components can be considered as
(i) Pure solvent $$ \to $$ separated solvent molecules, $$\Delta $$H₁
(ii) Pure solute $$ \to $$ separated solute molecules, $$\Delta $$H₂
(iii) Separated solvent and solute molecules $$ \to $$ solution, $$\Delta $$H₃
Solution so formed will be ideal if

What is the entropy change (in J K^$$-$$1 mol^$$-$$1) when one mole of ice is converted into water at 0^oC? (The enthalpy change for the conversion of ice to liquid water is 6.0 kJ mol^$$-$$1 at 0^oC).

For which one of the following equations is $$\Delta $$H^o_react equal to $$\Delta $$H^o_f for the product ?

The molar heat capacity of water at constant pressure, C, is 75 J K^$$-$$1 mol^$$-$$1. When 1.0 kJ of heat is supplied to 100 g of water which is free to expand, the increase in temperature of water is

Which one of the following statements is not true?

The reaction quotient (Q) for the reaction

N_2(g) + 3H_2(g) $$\rightleftharpoons$$ 2NH_3(g) is given by

$$Q = {{{{\left[ {N{H_3}} \right]}^2}} \over {\left[ {{N_2}} \right]{{\left[ {{H_2}} \right]}^3}}}$$.

The reaction will proceed from right to left if

The solubility product of AgI at 25^oC is 1.0 $$ \times $$ 10^$$-$$16 mol² L^$$-$$2. The solubility of AgI in 10^$$-$$4 N solution of KI at 25^oC is approximately (in mol L^$$-$$1

Name of the compound given below is

Which one of the following orders of acid strength is correct ?

The compound

on reaction with NaIO₄ in the presence of KMnO₄ gives

Which one of the following is a free-radical substitution reaction ?

The correct order of reactivity towards the electrophilic substitution of the compounds aniline (I), benzene (II) and nitrobenzene (III) is

Which of the following pairs of compounds are enantiomers?

The oxidation states of sulphur in the anions

SO3$${_3^{2 - }}$$, S₂O$${_4^{2 - }}$$ and S₂O$${_6^{2 - }}$$ follow the order

An equiconvex lens is cut into two halves along (i) XOX' and (ii) YOY' as shown in the figure. Let $$f,f',$$ $$f''$$ be the focal lengths of the complete lens, of each half in case (i), and of each half in case (ii), respectively.

Choose the correct statement from the following

Two 220 volt, 100 watt bulbs are connected first in series and then in parallel. Each time the combination is connected to a 220 volt a.c. supply line. The power drawn by the combination in each case respectively will be

Fuse wire is a wire of

In a Wheatstone's bridge all the four arms have equal resistance R. If the resistance of the galvanometer arm is also R, the equivalent resistance of the combination as seen by the battery is

An electric kettle has two heating coils. When one of the coils is connected to an a.c. source, the water in the kettle boils in 10 minutes. When the other coil is used the water boils in 40 minutes. If both the coils are connected in parallel, the time taken by the same quantity of water to boil will be

A long solenoid carrying a current producess a magnetic field B along its axis. If the current is doubled and the number of turns per cm is halved, the new value of the magnetic field is

A charged particle moves through a magnetic field in a firection perpendicular to it. Then the

A diamagnetic material in a magnetic field moves

According to Curie's law, the magnetic susceptibility of a substance at an absolute temperature $$T$$ is proportional to

A bar magnet is oscillating in the Earth's magnetic field with a period T. What happens to its period and motion if its mass is quadrupled?

Which of the following rays are not electromagnetic waves ?

We consider the radiation emitted by the human body. Which one of the following statements is true?

A convex lens is dipped in a liquid whose refractive index is equal to the refractive index of the lens. Then its focal length will

A charge q is located at the centre of a cube. The electric flux through any face is

A photoelectric cell is illuminated by a point source of light 1 m away. When the source is shifted to 2 m then

J.J. Thomson's cathode-ray tube experiment demonstrated that

An electron is moving round the nucleus of a hydrogen atom in a circular orbit of radius r. The Coulomb force $$\overrightarrow F $$ between the two is

Solar energy is mainly caused due to

The volume occupied by an atom is greater than the volume of the nucleus by a factor of about

The mass of proton is 1.0073 u and that of neutron is 1.0087 u (u = atomic mass unit). The binding energy of $${}_2^4$$ He is
(Given helium nucleus mass $$ \approx $$ 4.0015 u.)

In which of the following systems will the radius of the first orbit (n = 1) be minimum ?

Reverse bias applied to a junction diode

Two spheres of masses m and M are situated in air and the gravitational force between them is F. The space around the masses is now filled with a liquid of specific gravity 3. The gravitational force will now be

A man throws balls with the same speed vertically upwards one after the other at an interval of 2 seconds. What should be the speed of the throw so that more than two balls are in the sky at any time ? (Given g = 9.8 m/s²)

The vector sum of two forces is perpendicular to their vector differences. In that case, the forces

A particle moves along a circle of radius $$\left( {{{20} \over \pi }} \right)$$ m with constants tangential acceleration. If the velocity of vthe particle is 80 m/s at the end of the second revoluation after motion has begun, the tangential acceleration is

A man weight 80 kg. He stands on a weighting scale in a lift which is moving upwards with a uniform acceleration of 5 m/s². What would be the reading on the scale ? (g = 10 m/s²)

A monkey of mass 20 kg is holding a vertical rope. The rope will not break when a mass of 25 kg is suspended from it but will break if the mass exceeds 25 kg. What is the maximum acceleration with which the monkey can climb up along the rope ? (g = 10 m/s²)

When a long spring is stretched by 2 cm, its potential energy is U. If the spring is stretched by 10 cm, the potential energy stored in it will be

A stationary particle explodes into two particles of masses m₁ and m₂ which move in opposite directions with velocities v₁ and v₂. The ratio of their kinetic energies E₁/E₂ is :

A ball rolls without slipping. The radius of gyration of the ball about an axis passing through its centre of mass is K. If radius of the ball be R. then the fraction of total energy associated with its rotational energy will be

A stone is tied to a string of length $$l$$ and is whirled in a vertical circle with the other end of the string as the centre. At a certain instant of time, the stone is at its lowest position and has a speed u. The magnitude of the change in velocity as it reaches a position where the string is horizontal (g being acceleration due to gravity) is

A solid cylinder of mass M and radius R rolls without slipping down an inclined plane of length L and height h. What is the speed of its centre of mass when the cylinder reaches its bottom ?

A thin circular ring of mass M and radius r is rotating about its axis with a constant angular velocity $$\omega $$. Four objects each of mass m, are kept gently to the opposite ends of two perpendicular diameters of the ring. The angular velocity of the ring will be :

The acceleration due to gravity on the planet A is 9 times the acceleration due to gravity on planet B. A man jumps to a height of 2 m on the surface of A. What is the height of jump by the same person on the planet B?

A body of mass m is placed on earth's surface which is taken from earth surface to a height of h = 3R, then change in gravitational potential energy is

Consider a compound slab consisting of two different materials having equal thicknesses and thermal conductivities K and 2K, respectively. The equivalent thermal conductivity of the slab is

An ideal gas heat engine operates in a Carnot cycle between 227^oC and 127^oC. It absorbs 6 kcal at the height temperature. The amount of heat (in kcal) converted into work is equal to

Which one of the following statements is true for the speed v and the acceleration a of a particle executing simple harmonic motion?

The potential energy of a simple harmonic oscillator when the particle is half way to its end point is

A particle of mass m oscillates with simple harmonic motion between points x₁ and x₂, the equilibrium position being O. Its potential energy is plotted. It will be as given below in the graph

In case of a forced vibration, the resonance peak becomes very sharp when the

The time period of mass suspended from a spring is T. If the spring is cut into four equal parts and the same mass is suspended from one of the parts, then the new time period will be

Three capacitors each of capacity 4 $$\mu $$F are to be connected in such a way that the effective capacitance is $$6\mu F.$$ This can be done by

If a full wave rectifier circuit is operating from 50 Hz mains, the fundamental frequency in the ripple will be

Barrier potential of a p-n junction diode does not depened on

If a ball is thrown vertically upwards with speed u, the distance covered during the last t seconds of its ascent is