KVPY Class-XII ...

The number of 5-tuples (a, b, c, d, e) of positive integers, such that

I. a, b, c, d and e are the measures of angles of a convex pentagon in degrees;
II. a ≤ b ≤ c ≤ d ≤ e; and
III. a, b, c, d and e are in arithmetic progression, is

The distance s travelled by a particle in time t is s = ut - 1/2 gh². The initial velocity of the particle was measured to be u = 1.11 ± 0.01 m/s and the time interval of the experiment was t = 1.01 ± 0.1 s. The acceleration was taken to be g = 9.8 ± 0.1 m/s². With these measurements, the student estimates the total distance travelled. How should the student report the result?

Which of the following statements for air molecules in an air tight container is/are true?

(I) The average speed of molecules is larger than root mean square speed.
(II) Mean free path of molecules is larger than the mean distance between molecules.
(III) Mean free path of molecules increases with temperature.
(IV) The rms speed of nitrogen molecule is smaller than oxygen molecule.

The most abundant metal ion present in the human body is

The complete hydrolysis of XeF₆ results in the formation of

Resting membrane potential of a neuron is approximately

Amphimixis is

Activation of sympathetic nervous system

At physiological temperature, sterols in biological membranes

Which of the following is a heteropolysaccharide?

Bacterial plasmids are genetic entities that

Skin prick test on the forearm is conducted to identify the responsible allergen. This is because

Which of the following processes in E.coli does not directly involve RNA?

Which of the following statements is incorrect for translation in cytoplasm?

Two homozygous parents harbouring two different alleles of a gene, exhibiting incomplete dominance for flower colour, were used for a genetic experiment. Which of the following statements is incorrect?

Which of the following conditions is essential for a population to be at Hardy-Weinberg equilibrium?

Inbreeding in a population leads to

If a pure chlorophyll solution is illuminated with ultraviolet light, then the solution appears

Botanical names of plants are given in Column - I and the family/order names are given in Column - Il. Choose the appropriate combination from the options given below.

Nitrogen fixation is inhibited by oxygen. However, in aerobic nitrogen fixing bacteria, nitrogen is fixed in the presence of oxygen. Nitrogenase in such organisms is protected by

Frederick Griffith performed an experiment where mice were killed when injected with a mixture of heat killed S-type Streptococcus (HKS) and live R-type Streptococcus (LRS), but not with HKS or LRS separately. The mice were killed because

In diabetic patients, the pH of blood plasma can decrease. This leads to acidosis. It occurs because tissues catabolise

If the number of alveoli in an individual is doubled without changing the total alveolar volume, then the gas exchange capacity of the lungs will

In an experiment, bacteria were infected with ³²P labelled viruses in the ratio 5 : 1. The culture was rigorously shaken, followed by centrifugation. Radioactivity was

Let A be a set of all permutations a₁, a₂, ..., a₆ of 1, 2, ..., 6 such that a₁, a₂, ..., a_k is not a permutation of 1, 2, .., k for any k, 1 ≤ k ≤ 5. Then, the number of elements in A is

Let f(x) be a polynomial with integer coefficients satisfying f(1) = 5 and f(2) = 7. The smallest possible positive value of f(12) is

Consider the following statements regarding the photoelectric effect experiment.

(I) Photoelectrons are emitted as soon as the metal is exposed to light.
(II) There is a minimum frequency below which no photo-current is observed.
(III) The stopping potential is proportional to the frequency of light.
(IV) The photo-current varies linearly with the intensity of light.

Which of the above statements indicate that light consists of quanta (photons) with energy proportional to frequency?

Suppose, non-linked autosomal genes A, B and C control coat colour in an animal, the dominant alleles A, B and C are responsible for dark colour and the recessive alleles a, b and c are responsible for light colour. If a cross between a male of AABBCC genotype and a female of aabbcc genotype produces 640 offsprings in the F₂ generation, then how many of them are likely to be of the parental genotype?

In a population of families having three children each, the percentage of population of families having both boys and girls is

Matthew Meselson and Franklin Stahl grew E.coli (doubling time is 20 mm) in a medium containing ¹⁵NH₄CI for many generations. Then, it was transferred to a medium containing ¹⁴NH₄CI. After 40 minutes, the cells were harvested and DNA was extracted and subjected to cesium chloride density gradient centrifugation. The proportion of light and hybrid DNA densities will be

Which of the following statements is correct in a population interaction between the species X and the species Y?

The protein P, the oligosaccharide O and the oligonucleotide N are composed of 100 amino acid residues, 100 hexose residues and 100 nucleotides, respectively. Which of the following orders of molecular weights is correct?

An octapeptide (NH₂-Asn-Glu-Tyr-Lys-Trp-Met-Glu-Gly) is subjected to complete protease and chemical digestion. Choose the incorrect option.

Match the enzymes in Column - I with their respective biochemical reactions in Column - Il.

Column - I	Column - Il
(P) Transaminases	(i) Removal of phosphoryl group from a specific amino acid
(Q) Protein kinases	(ii) Removal of -amino group from a specific amino acid
(R) Protein Phosphatases	(iii) Addition of phosphoryl group to a specific amino acid
(S) Dehydrogenases	(iv) Interconversion of optical isomers
	(v) Oxidation and reduction of substrates