NEET Class 12

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 Multiple Choice QuestionsMultiple Choice Questions


Virus was discovered by whom

  • Stanley

  • Ivanowski

  • Herelle

  • Beijerinck



Ivanoski reported in 1892 that extracts from infected leaves were still infectious after filtration through a Chamberland filter-candle. Bacteria are retained by such filters, a new world was discovered: filterable pathogens. However, Ivanovski probably did not grasp the full meaning of his discovery. Beijerinck, in 1898, was the first to call 'virus', the incitant of the tobacco mosaic. He showed that the incitant was able to migrate in an agar gel, therefore being an infectious soluble agent, or a 'contagium vivum fluidum' and definitively not a 'contagium fixum' as would be a bacteria. Ivanovski and Beijerinck brought unequal but decisive and complementary contributions to the discovery of viruses.


The average diameter of red blood corpuscles of man is

  • 7.2 µm

  • 8.1 µm

  • 9.2 µm

  • 10.3 m


7.2 µm

Normal RBCs have a diameter of6 - 7.5 μm. On a peripheral blood smear, normal RBCs are disc-shaped with a pale-staining central area called the central pallor. When judging red cell size on a blood smear, the classic rule of thumb is to compare them to the nucleus of a small normal lymphocyte


The chemical nature of hormones secreted byα andβcells of pancreas is

  • glycolipid

  • glycoprotein

  • steroid

  • polypeptide




Which one is product of aerobic respiration

  • Malic acid 

  • Ethyl alcohol

  • Lactic acid

  • Pyruvic acid


Lactic acid

If the breathing rate and blood flow cannot supply enough oxygen to your working muscles, the body turns toanaerobic respiration. This is the production of energy without the use of oxygen. This system works by producinglactic acidto facilitate energy production.


In which stage of cell division chromosomes are most condensed

  • Prophase

  • Metaphase

  • Anaphase

  • Telophase



'Anaphase', is the stage of mitosis after the metaphase when replicated chromosomes are split and the daughter chromatids are moved to opposite poles of the cell. Chromosomes also reach their overall maximum condensation in late anaphase, to help chromosome segregation and the re-formation of the nucleus.


How many ATP molecules are obtained from fermentation of 1 molecule of glucose

  • 4

  • 3

  • 5


The net energy gain in fermentation is2ATP molecules/glucose molecule. In both lactic acid and alcoholic fermentation, all the NADH produced in glycolysis is consumed in fermentation, so there is no net NADH production, and no NADH to enter the ETC and form more ATP.


Electron microscope is based on the principle of

  • electromagnetic theory

  • resolution of glass lenses

  • magnification of glass lenses

  • refraction of light


electromagnetic theory

Anelectron microscopeuses an 'electronbeam' to produce the image of the object and magnification is obtained by 'electromagnetic fields'; unlike light or opticalmicroscopes, in which 'light waves' are used to produce the image and magnification is obtained by a system of 'optical lenses'.


FAD is electron acceptor during oxidation of which of the following

  • ketoglutarate ➔ Succinyl Co-A

  • Succinic acid➔ Fumaric acid

  • Succinyl Co-A ➔ Succinic acid

  • Fumaric acid ➔ Malic acid


Succinic acid➔ Fumaric acid

In biochemistry,flavin adenine dinucleotide(FAD) is a redopx-active coenzymeassociated with various protiens, which is involved with several important enzymatic reactions in metabolism. A flavoprotienis a protein that contains a flavin group, this may be in the form of FAD or flavin mononucleotide(FMN).


Citric acid cycle is the alternate name of which of the following

  • HMP shunt

  • Glycolysis

  • TCA cycle

  • Calvin cycle


TCA cycle

Thetricarboxylic acid cycle(TCA cycle) is aseries of enzyme-catalyzed chemical reactions that formakey part of aerobic respiration in cells. Thiscycle is also calledtheKrebs cycleand thecitric acid cycle.


CO2 acceptor in C3 cycle is

  • OAA

  • RuBP

  • PEP

  • Malic acid



Primarycarbon dioxide acceptorin C4 plant is phosphoenol pyruvic acid,it contains 3 carbon atoms. in C3 plants ribulose 1,5 bisphosphate (RUBP) is the primaryCO2 acceptor. It is a 5 carbon compound. In C4 plants phospho enol pyruvate (PEP) is primaryCO2 acceptor.