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KVPY Class 12 Test

User: GovindStarted On: 19 Oct 2013, 16:16:43Total Score: 60/240

Subject: Physics (Attempted Ques)

Subject: Chemistry (Attempted Ques)

Question 1:

Correct Answer: 1

Your Answer: 1

Solution Steps:

Question 2:

Correct Answer: K1K22

Your Answer: K1K22

Solution Steps:

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KVPY Class 12 Test

Question 3: Doping silicon with boron produces a :

Correct Answer: p-type semiconductor

Your Answer: n-type semiconductor

Solution Steps: Doping with trivalent impuring produces p-type semiconductor.

Question 4: For a one-electron atom, the set of allowed quantum numbers is :

Correct Answer:

Your Answer:

Question 5: Typical electronic energy gaps in molecules are about 1.0 eV. In terms of temperature, the gap is

closest to :

Correct Answer: 103 K

Your Answer: 103 K

Solution Steps:

Question 6:

Correct Answer: 0

Your Answer: 3

Solution Steps: All ligands are neutral.

Question 7:

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KVPY Class 12 Test

Correct Answer: 4

Your Answer: 1

Solution Steps:

Question 8:

Correct Answer: 3

Your Answer: 3

Solution Steps: Staggered is most stable

Question 9: For a tetrahedral complex [MCl4]2–, the spin-only magnetic moments is

3.83 BM. The element M is :

Correct Answer: Co

Your Answer: Co

Solution Steps:

Question 10: The C–O bond length in CO, CO2, and CO32– follows the

order :

Correct Answer: CO < 2 < CO32–

Your Answer: CO > CO2 > CO32–

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KVPY Class 12 Test

Solution Steps: As decided by bond orderCO < CO2 < CO32–

Question 11: The isoelectronic pair of ions is :

Correct Answer: Mn2+ and Fe3+

Your Answer: Mn3+and Fe2+

Solution Steps: Both have 24 electrons.

Subject: Mathematics (Attempted Ques)

Subject: Biology (Attempted Ques)

Question 1: A reflex action is a quick involuntary response to stimulus. Which of the following is an example of

BOTH, unconditioned and conditioned reflex ?

Correct Answer: secretion of saliva in response to the aroma of food

Your Answer: secretion of saliva in response to the aroma of food

Solution Steps: Secretion of saliva in response to the aroma of food could be both unconditional and conditional

reflex.

Question 2: The disorders that arise when the immune system destroys ‘self’ cells are called autoimmune

disorders.

Which of the following would be classified under this ?

Correct Answer: rheumatioid arthritis

Your Answer: rheumatioid arthritis

Solution Steps: Rhematioid arthritis is an autoimmune disease while rhinits, asthma and eczema are inflammatorydisease

of, mucous membrane inside nose, bronchioles and epidermis respectively.

Question 3: Peptic ulcers are caused by :

Correct Answer: a bacterium Helicobacter pylori

Your Answer: a bacterium Helicobacter pylori

Solution Steps: Helicobacter pylori previously named compylobacter pyloridis, is a gram – negative bacteria found instomach, causes peptic ulcers.

Question 4: Vitamin A deficiency leads to night-blindness. Which of the following is the reason for the disease ?

Correct Answer: rhodopsin pigment of rod cells is defective

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KVPY Class 12 Test

Your Answer: rhodopsin pigment of rod cells is defective

Solution Steps: Vitamins A is structural component of visual pigment. “Rhodopsin”, vitamin A deficiency may leads tonightblindness because rhodopsin pigment of rod cells become defective.

Question 5: Diabetes insipidus is due to :

Correct Answer: hyposecretion of vasopressin

Your Answer: hypersecretion of vasopressin

Solution Steps: Vasopressin or ADH hormone induce reabsorption of water in DCT and collecting duct of nephron.It’shyposecretion may cause frequent urination which is also called Diabetes insipidus.

Question 6: Which of the following is true TCA cycle in eukaryotes ?

Correct Answer: takes place in mitochondrion

Your Answer: takes place in mitochondrion

Solution Steps: Kreb Cycle/TCA cycle in eukaryotes takes place in mitochondria.

Question 7: In mammals, the hormones secreted by the pituitary, the master gland, is itself regulated by the

pituitary, the master gland, is itself regulated by :

Correct Answer: hypothalamus

Your Answer: hypothalamus

Solution Steps: Secretion of hormones by the pituitary gland is regulated by a part of brain “hypothalamus”.

Question 8: Which of the following class of immunoglobulin can trigger the complement cascade ?

Correct Answer: IgM

Your Answer: IgA

Solution Steps: Classical complement pathway comprising of 21 different serum proteins primarily activated byantibodymolecules of either IgG or IgM.

Question 9: Fossils are most often in which kind of rocks ?

Correct Answer: sedimentary rocks

Your Answer: sedimentary rocks

Solution Steps: Fossils are most often found in Sedimentary kind of rocks.

Question 10: DNA mutations that do not cause any functional change in the protein product are known as :

Correct Answer: silent mutations

Your Answer: silent mutations

Solution Steps: Silent mutations are DNA mutations that do not result in a change to the amino acid sequence of a

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KVPY Class 12 Test

protein.

Question 11: Transfer RNA (tRNA)

Correct Answer: usually has clover leaf-like structure

Your Answer: codes for proteins

Solution Steps: rRNA is present in the ribosomes and mRNA carries genetic information from DNA and codes forprotein,while tRNA carries amino acids at site of protein synthesis and also have clover leaf-like sturcture

Question 12: By which of the following mechanisms is glucose reabsorbed from the glomerular filtrate by the

kideny tubule ?

Correct Answer: diffusion

Your Answer: diffusion

Solution Steps: In kidney tubule PCT, 100% glucose from glomerular filtrate is reabsorbed by diffusion.

Question 13: A ripe mango, kept with unripe mangoes causes their ripening. This is due to the release of a

gaseous plant hormone.

Correct Answer: ethylene

Your Answer: ethylene

Solution Steps: Ethylene is only gaseous plant hormone that induce ripening of fruit.

Question 14: A hormone molecule binds to a specific protein on the plasma membrane inducing a signal. The

protein it binds to is called :

Correct Answer: receptor

Your Answer: receptor

Solution Steps: Proteins on plasma membrane to which hormone molecules bind is called receptor.

Question 15: In a food chain such as grass --> deer --> lion, the energy cost of respiration as a proportion of total

assimilated energy at each level would be :

Correct Answer: 30%- 30% - 30%

Your Answer: 30%- 30% - 30%

Solution Steps: According to 10% low at each tropic leve 90% of assimilated energy is lost in respiration and only10% ispass on the next level so respiration energy loss would be constant at each tropic level.

Question 16: Plant roots are usually devoid of chlorophyll and cannot perform photosynthesis. However, there are

exceptions. Which of the following plant root can perform photosynthesis ?

Correct Answer: Tinospora

Your Answer: Tinospora

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KVPY Class 12 Test

Solution Steps: Some plants develop green, chlorophyll containing roots along with colourless roots, these greenrootsperform photosynthesise.g. – Trapa and Tinospora

Question 17: Some animals excrete uric acid in urine (uricotelic) as it requires very little water loss. Which animals

among the following are most likely to be uricotelic ?

Correct Answer: birds

Your Answer: birds

Solution Steps: Birds are uricotelic.

Question 18: In Dengue virus infection, patients often develop haemorrhagic fever due to internal bleeding. This

happens due to the reduction of :

Correct Answer: platelets

Your Answer: platelets

Solution Steps: Haemorrhagic fever in dengue virus infection may cause internal bleeding due to the reduction ofplatelets.

Question 19: Human chromosomes undergo structural changes during the cell cycle. Chromosomal structure can

be best visualized if a chromosome is isolated from a cell at :

Correct Answer: M phase

Your Answer: M phase

Solution Steps: Chromosomal structure can be best visualized in metaphase of M Phase .

Question 20: If the sequence of bases in sense strand of DNA is 5’ – GTTCATCG-3’, then the sequence of bases

in its RNA transcript would be :

Correct Answer: 5’-GUUCAUCG-3’

Your Answer: 5’-GUUCAUCG-3’

Solution Steps: Transcribed RNA is exactly like that of the sense strand of DNA2

DNA --> 51 - GTTCATCG – 3’RNA --> 51 – GUUCAUCG – 3’

Question 21: In cattle, the coat colour red and white are two dominant traits, which express equally in F1 to

produce roan (red and white colour in equal proportion). If F1 progeny are self-bred, the resulting

progeny in F2 will

have phenotypic ratio (red : roan : white) is :

Correct Answer: 1 : 2 : 1

Your Answer: 1 : 2 : 1

Solution Steps:

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KVPY Class 12 Test

Question 22: Insects constitute the largest animals group on earth. About 25-30% of the insect species are known

to be herbivores. In spite of such huge herbivore pressure, globally, green plants have persisted.

One possible reason for this persistence is :

Correct Answer: herbivore population has been kept in control by predators

Your Answer: herbivore population has been kept in control by predators

Solution Steps: Herbivore population has bee kept in control by predators.

Question 23: Insectivorous plants that mostly grow on swampy soil use insects as a source of :

Correct Answer: nitrogen

Your Answer: nitrogen

Solution Steps: Insectivorous plants use insects as source of nitrogen.

Question 24: The roots of some higher plants get associated with a fungal partner. The roots provide food to the

fungus while the funus supplies water to the roots. The structure so formed is known as

Correct Answer: mycorrhiza

Your Answer: mycorrhiza

Question 25: Persons suffering from hypertension (high blood pressure) are advised a low-salt diet because :

Correct Answer: high salt leads to water retention in the blood that further increases the blood pressure

Your Answer: high salt leads to water retention in the blood that further increases the blood pressure

Solution Steps: High salt leads to water retention in the blood that increases blood volume and further increases thebloodpressure.

Question 26: The following sequence contains the open reading frame of a polypeptide. How many amino acids

will the polypeptide consist of ?

5’-AGCATATGATCGTTTCTCTGCTTTGAACT-3’

Correct Answer: 7

Your Answer: 7

Solution Steps: The following sequence contains the open reading frame of a polypeptide. How many amino acidswill thepolypeptide consist of ?5’-AGCATATGATCGTTTCTCTGCTTTGAACT-3’

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KVPY Class 12 Test

Question 27: Vibrio cholerae cuases cholera in humans. Ganga water was once used successfully to combat the

infection. The possible reason could be :

Correct Answer: presence of antibiotics in Ganga water

Your Answer: presence of bacteriophages in Ganga waterSolution Steps: Ganga water may possibly contain antibiotic that may kill vibrio cholerae bacteria certainly.

Question 28: When hydrogen peroxide is applied on the wound as a disinfectant, there is frothing at the site of

injury, which is due to the presence of an enzyme in the skin that sues hydrogen peroxide as a

substrate to produce :

Correct Answer: oxygen

Your Answer: oxygen

Solution Steps: Peroxidase enzyme use hydrogen peroxide as a substrate to produce oxygen that cause frothing at

thesite of injury.

Question 29:

Correct Answer: 1

Your Answer: 1

Solution Steps: On starting fast glucose level decreased and than remain constant as glucose began to mobilize

fromstored glycogen in liver and then further decreased.

Question 30: Which one of the following is true about enzyme catalysis ?

Correct Answer: the activation barrier of the process is lower in the presence of an enzyme

Your Answer: the activation barrier of the process is lower in the presence of an enzyme

Solution Steps: Enzyme serve as biocatalyst, it increases rate of a biological reaction by decreasing activationenergy.

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