datavorous/entrance-exam-dataset huggingface dataset:
Which one of the following microbes forms symbiotic association with plants and helps them in their nutrition?

Options:
A Azotobacter
B Aspergillus
C Glomus
D Trichoderma

The correct answer is:
Glomus

Solution:
Several species of Glomus, including G. aggregatum, are cultured and sold as mycorrhizal inoculant for agricultrural soils. Being endomycorrhiza, it helps the plants in the absorption of nutrients especially phosphorus from soil.

Topic: Biology, Mineral Nutrition, NEET, NEET 2012 (Screening)
Which one of the following mixtures is suitable for making a buffer solution with an optimum pH of 9.2 – 9.3?

Options:
A CH3CO2Na/CH3CO2H(Ka=1.8×10-5)
B NH3/NH4Cl(Ka(NH4+)=5.6×10-10)
C NaNO2/HOCl(Ka=4.5×10-8)
D NaNO2/HNO2(Ka=4.5×10-4)

The correct answer is:
NH3/NH4Cl(Ka(NH4+)=5.6×10-10)

Solution:
pH of 9.2 – 9.3 is produced by a basic buffer obtained by mixing a weak base (like NH3 ) with its salt formed by the reaction of NH3 with strong acid (NH3+HCl→NH4Cl) .

Topic: Chemistry, Ionic Equilibrium, NEET
Which one of the following molecular hydrides acts as a Lewis acid ?

Options:
A $\mathrm{NH}_3$
B $\mathrm{H}_2 \mathrm{O}$
C $\mathrm{B}_2 \mathrm{H}_6$
D $\mathrm{CH}_4$

The correct answer is:
$\mathrm{B}_2 \mathrm{H}_6$

Solution:
Key Idea:- Electron deficient molecules behave as Lewis acid.
Among the given molecules, only diborane is electron deficient, ie, does not have complete octet. Thus, it acts as a Lewis acid.
$\mathrm{NH}_3$ and $\mathrm{H}_2 \mathrm{O}$ being electron rich molecules behave as Lewis base.

Topic: Chemistry, Ionic Equilibrium, NEET, NEET 2010 (Screening)
Which one of the following molecular hydrides acts as a Lewis acid?

Options:
A CH4
B NH3
C H2O
D B2H6

The correct answer is:
B2H6

Solution:
B2H6 is a Lewis acid here as it is electron deficient (6 electron) so it can accept electrons. NH3,H2O are Lewis bases as they have lone pair of electrons to donate. CH4 is neither Lewis acid nor Lewis base as it can not donate (have no lone pair) or accept electron (have no vacant orbital).

Topic: Chemistry, Ionic Equilibrium, NEET
Which one of the following molecules can serve as a monomer for an addition polymer?

Options:
A H2C=CH-C6H5
B H2C=CHCN
C ClCH=CH2
D All of these

The correct answer is:
All of these

Solution:
For addition polymerisation, the monomers used are unsaturated compounds and commonly derivatives of ethene. Here all are monomers for addition polymers. For e.g., ClCH=CH2 (monomer of PVC), H2C=CHCN (monomer of orlon)

Topic: Chemistry, Polymers, NEET
Which one of the following molecules cannot serve as a monomer for an addition polymer?

Options:
A ClCH=CH2
B H2C=CHCN
C H2C=CH-C6H5
D

The correct answer is:

Solution:
Here cannot serve as a monomer for an addition polymer as in addition polymerisation, the monomers are unsaturated compounds and commonly derivatives of ethene. Rest other are monomers for addition polymers. For e.g., ClCH=CH2 (monomer of PVC)

Topic: Chemistry, Polymers, NEET
Which one of the following molecules contain no $\pi$-bond?

Options:
A $\mathrm{CO}_2$
B $\mathrm{H}_2 \mathrm{O}$
C $\mathrm{SO}_2$
D $\mathrm{NO}_2$

The correct answer is:
$\mathrm{H}_2 \mathrm{O}$

Solution:
All the molecules have $\mathrm{O}$ atom with lone pairs, but in $\mathrm{H}_2 \mathrm{O}$ the $\mathrm{H}$ atom has no vacant orbital for $\pi$ bonding. That's why it does not have any $\pi$ bond.
In all other given molecules, the central atom because of the presence of vacant orbitals is capable to farm $\pi$ bonds.

Topic: Chemistry, Chemical Bonding and Molecular Structure, NEET, NEET 2013 (All India)
Which one of the following molecules contains no π bond?

Options:
A H2O
B SO2
C NO2
D CO2

The correct answer is:
H2O

Solution:
don't have any pi-bond and have only 2 sigma bonds.
SO2 and CO2 both have 2 sigma and 2 pi bonds.
NO2 have 2 sigma and 1 pi bonds.

Topic: Chemistry, Chemical Bonding and Molecular Structure, NEET
Which one of the following molecules is planar?

Options:
A NF3
B NCl3
C PH3
D BF3

The correct answer is:
BF3

Solution:
NF 3 , NCl 3 , PH 3 have pyramidal geometry. sp3 hybridisation
BF 3 - planar sp2 hybridisation.

Topic: Chemistry, Chemical Bonding and Molecular Structure, NEET
Which one of the following monomers gives the polymer neoprene on polymerization?

Options:
A $\mathrm{CH}_2=\mathrm{CHCl}$
B $\mathrm{CCl}_2=\mathrm{CCl}_2$
C

D $\mathrm{CF}_2=\mathrm{CF}_2$

The correct answer is:

Solution:
2-chloro but-2-ene (or Chloroprene) is the monomer of neoprene.
Related Theory
Neoprene elastomer was first synthesized in the 1930 s and became the first synthetic elastomer to provide significant advantages over natural rubber.
Caution
Neoprene is not a condensation polymer. It is an additional polymer. Neoprene is formed by the free radical or monomer polymerization of chloroprene.

Topic: Chemistry, Polymers, NEET, NEET 2003
Which one of the following mRNA sequences can be translated completely?

Options:
A AUG UUC UCC UGG UAA UAU
B AUG UUC UCC UGA UGG UAU
C AUG ACG UAU UUC UGA CUC
D AUG UAU UUC UGC CUC UAG

The correct answer is:
AUG UAU UUC UGC CUC UAG

Solution:
Because in this mRNA, AUG is the initiation codon and UAG, UGA and UAA are the termination codons.

Topic: Biology, Molecular Basis of Inheritance, NEET
Which one of the following never occurs during mitotic cell division?

Options:
A Movement of centrioles towards opposite poles
B Pairing of homologous chromosomes
C Coiling and condensation of the chromatids
D Spindle fibres attach to kinetochores of chromosomes

The correct answer is:
Pairing of homologous chromosomes

Solution:
Mitosis doesn't have a pairing of homologous chromosomes, it occurs in prophase 1 of meiosis 1 where bivalent and tetrad are formed

Topic: Biology, Cell Cycle and Cell Division, NEET, NEET 2022 (Phase 1)
Which one of the following nitroalkanes will give nitrolic acid with NaNO2/conc.H2SO4

Options:
A
B
C
D All of these

The correct answer is:

Solution:
Primary nitroalkane gives nitrolic acid with HNO2

Topic: Chemistry, Amines, NEET
Which one of the following nitroalkanes will give nitrolic acid with NaNO2/Conc.H2SO4?

Options:
A
B
C
D All of the above

The correct answer is:

Solution:
Pimary nitroalkane gives nitrolic acid with HNO2

Topic: Chemistry, Amines, NEET
Which one of the following nitro-compounds does not react with nitrous acid?

Options:
A
B
C
D

The correct answer is:

Solution:
Nitro compounds that contain acidic hydrogen react with nitrous acid. Here, in this molecule no acidic hydrogen is present. Therefore, it does not react with nitrous acid. All other given compounds contain the acidic hydrogens.

No acidic H-atom on the carbon atom having NO2-group.

Topic: Chemistry, Amines, NEET, NEET 2016 (Phase 2)
Which one of the following noble gas is obtained by radioactive disintegration?

Options:
A Kr
B Ar
C Rn
D Xe

The correct answer is:
Rn

Solution:
Rn is a radiactive and its produced by the decay of radium and thorium mineral
88226Ra→86222Rn+24He
It is a γ -emitter.

Topic: Chemistry, Chemical Kinetics, NEET
Which one of the following octahedral complexes will not show geometric isomerism?
( $\mathrm{A}$ and $\mathrm{B}$ are monodentate ligands)

Options:
A $\left[\mathrm{MA}_2 \mathrm{~B}_4\right]$
B $\left[\mathrm{MA}_3 \mathrm{~B}_3\right]$
C $\left[\mathrm{MA}_3 \mathrm{~B}_3\right]$
D $\left[\mathrm{MA}_5 \mathrm{~B}\right]$

The correct answer is:
$\left[\mathrm{MA}_5 \mathrm{~B}\right]$

Solution:
Geometric isomerism occurs in octahedral complexes when there are at least two different types of ligands or when there is a bidentate ligand present. Geometric isomerism is not possible when all ligands are the same type and are monodentate. In such cases, the ligands can only occupy adjacent positions in the octahedral coordination sphere.
Among the options given:
(1) \(\left[M A_2 B_4\right]\) has two types of ligands (\(A\) and \(B\)), so it can exhibit geometric isomerism.
(2) \(\left[M A_3 B_3\right]\) has two types of ligands (\(A\) and \(B\)), so it can exhibit geometric isomerism.
(3) \(\left[M_4 B_2\right]\) has two types of ligands (\(A\) and \(B\)), so it can exhibit geometric isomerism.
(4) \(\left[\mathrm{MA}_5 \mathrm{~B}\right]\) has only one type of ligand (\(A\)), and they are all monodentate. Therefore, it will not show geometric isomerism.

Topic: Chemistry, Coordination Compounds, NEET, NEET 2003
Which one of the following octahedral complexes will not show geometrical isomerism? (A and B are monodentate ligands)

Options:
A [MA4B2]
B [MA5B]
C [MA2B4]
D [MA3B3]

The correct answer is:
[MA5B]

Solution:
[MA5B] due to absence of symmetry of 'B ' ligand cannot exist in the form of cis-trans isomer.

Topic: Chemistry, Coordination Compounds, NEET
Which one of the following on treatment with $50 \%$ aqueous sodium hydroxide yields the corresponding alcohol and acid?

Options:
A $\mathrm{C}_6 \mathrm{H}_5 \mathrm{CHO}$
B $\mathrm{CH}_3 \mathrm{CH}_2 \mathrm{CH}_2 \mathrm{CHO}$
C

D $\mathrm{C}_6 \mathrm{H}_5 \mathrm{CH}_2 \mathrm{CHO}$

The correct answer is:
$\mathrm{C}_6 \mathrm{H}_5 \mathrm{CH}_2 \mathrm{CHO}$

Solution:
According to Cannizzaro's reaction.
$2 \mathrm{C}_6 \mathrm{H}_5 \mathrm{CHO}+\mathrm{NaOH} \stackrel{50 \% \mathrm{NaOH}}{\rightleftharpoons} \mathrm{C}_6 \mathrm{H}_5 \mathrm{COONa}+\mathrm{C}_6 \mathrm{H}_5 \mathrm{CH}_2 \mathrm{OH}$
Related Theory
Aldehydes containing no $\alpha$-hydrogen atom on warming with $50 \% \mathrm{NaOH}$ or $\mathrm{KOH}$ undergo disproportionation i.e. self oxidation reduction known as Cannizzaro's reaction.
Caution
Aldehydes that contains alpha hydrogen atoms are not involved in Cannizzaro reaction.

Topic: Chemistry, Aldehydes and Ketones, NEET, NEET 2007
Which one of the following options gives one correct example each of convergent evolution and divergent evolution?

Options:
A (a)
B (b)
C (c)
D (d)

The correct answer is:
(a)

Solution:
Convergent evolution involves the independent development of similar structures in organisms that are not directly related. It is represented by analogous organs, e.g., eyes of Octopus and mammals, wings of insects and birds. In divergent evolution, same basic organ becomes adapted by specialization to perform different functions. It is represented by homologous organs, e.g., fore limbs of vertebrates (like seal's flipper, bat's wing, cat's paw horse's front leg and human hand), thorns of Bougainvillia and tendrils of Cucurbita.

Topic: Biology, Evolution, NEET, NEET 2012 (Screening)
Which one of the following options is correct if the activation energies of two reactions are Ea1 and Ea2 with Ea1>Ea2 and if the temperature of the reacting systems is increased from T to TÂ´?

Options:
A k1 ′ k 1 = k 2 ′ k 2
B k 1 ′ k 1 <2 k 2 ′ k 2
C k 1 ′ k 1 > k 2 ′ k 2
D k 1 ′ k 1 < k 2 ′ k 2

The correct answer is:
k 1 ′ k 1 > k 2 ′ k 2

Solution:
Apply the Arrhenius equation.

k=Ae-EaRT

Take natural logarithm on both sides.

lnk=lnAâEaRT
In k1â²k=EaR1T-1Tâ²=EaRÃâTTTâ²
âT is positive, therefore greater the Ea value, greater will be the value of kâ²k
â´ k1â²k1>k2k2

Topic: Chemistry, Chemical Kinetics, NEET
Which one of the following options is incorrect?

Options:
A Hinge joint – between humerus and pectoral girdle
B Pivot joint – between atlas, axis and occipital condyle
C Gliding joint – between the carpals
D Saddle joint – between carpal and metacar- pals of thumb

The correct answer is:
Hinge joint – between humerus and pectoral girdle

Solution:
A hinge joint allows movement in one plane. Joint between the humerus and pectoral girdle is an example of a ball and socket joint.

Topic: Biology, Locomotion and Movement, NEET
Which one of the following order is wrong, with respect to the property indicated?

Options:
A Benzoic acid > phenol > cyclohexanol (acidic strength)
B Aniline > cyclohexylamine > benzamide (basic strength)
C Formic acid > acetic acid > propanoic acid (acid strength)
D Fluoroacetic acid > chloroacetic acid > bromoacetic acid (acid strength)

The correct answer is:
Aniline > cyclohexylamine > benzamide (basic strength)

Solution:
Basic strength decreases as,
cyclohexylamine > aniline > benzamide
Lesser basicity in aniline and benzamide is due to participation of lone pair of electron of -NH2 group.

Topic: Chemistry, General Organic Chemistry, NEET
Which one of the following orders correctly represents the increasing acid strengths of the given acids?

Options:
A $\mathrm{HOClO} < \mathrm{HOCl} < \mathrm{HOClO}_3 < $ $\mathrm{HOClO}_2$
B $\mathrm{HOClO}_2 < \mathrm{HOClO}_3 < \mathrm{HOClO} < $ $\mathrm{HOCl}$
C $\mathrm{HOClO}_3 < \mathrm{HOClO}_2 < \mathrm{HOClO} < $ $\mathrm{HOCl}$
D $\mathrm{HOCl} < \mathrm{HOClO} < \mathrm{HOClO}_2 < $ $\mathrm{HOClO}_3$

The correct answer is:
$\mathrm{HOCl} < \mathrm{HOClO} < \mathrm{HOClO}_2 < $ $\mathrm{HOClO}_3$

Solution:
As the oxidation number of the central atom increases, strength of acid also increases.
$\mathrm{HOCl} < \mathrm{HOClO} < \mathrm{HOClO}_2 < \mathrm{HOClO}_3$
Related Theory
The chlorine is more electronegative than bromine. As a result, it will attract electrons more towards itself than bromine. This will result in a donation of $\mathrm{H}+$ more easily in $\mathrm{HOCl}$ than in HOBr. So, the HOCl will be stronger acid than $\mathrm{HOBr}$.

Topic: Chemistry, p Block Elements (Group 15, 16, 17 & 18), NEET, NEET 2007
Which one of the following orders is correct for the bond dissociation enthalpy of halogen molecules?

Options:
A I2>Br2>Cl2>F2
B Cl2>Br2>F2>I2
C Br2>I2>F2>Cl2
D F2>Cl2>Br2>I2

The correct answer is:
Cl2>Br2>F2>I2

Solution:
Decreasing order of Bond energy, Cl2>Br2>F2>I2
The reason is anomalous behavior due to large electron - electron repulsion among the lone pairs in F2 molecule other than Cl2 and Br2 .

Topic: Chemistry, Classification of Elements and Periodicity in Properties, NEET, NEET 2016 (Phase 1)
Which one of the following orders is not in accordance with the property stated against it?

Options:
A $\mathrm{F}_2>\mathrm{Cl}_2>\mathrm{Br}_2>\mathrm{I}_2$ : bond dissociation energy
B $\mathrm{F}_2>\mathrm{Cl}_2>\mathrm{Br}_2>\mathrm{I}_2$ : oxidising power
C $\mathrm{HI}>\mathrm{HBr}>\mathrm{HCI}>\mathrm{HF}$; acidic property in water
D $\mathrm{F}_2>\mathrm{Cl}_2>\mathrm{Br}_2>\mathrm{I}_2$ : electronegativity

The correct answer is:
$\mathrm{F}_2>\mathrm{Cl}_2>\mathrm{Br}_2>\mathrm{I}_2$ : bond dissociation energy

Solution:
Bond dissociation energy of halogen family decreases down the group as the size of atom increases. The decreasing order for the bond dissociation enthalpy of halogen molecules is
$\mathrm{Cl}_2(57 \mathrm{kcal} / \mathrm{mol})>\mathrm{Br}_2(45.5 \mathrm{kcal} /$ $\mathrm{mol})>\mathrm{F}_2(38 \mathrm{kcal} / \mathrm{mol})>\mathrm{I}_2(35.6$ $\mathrm{kcal} / \mathrm{mol}$ ).
A Caution
A halogen molecule having larger atoms should have low dissociation energy and vice versa. Fluorine is an exception because of interelectronic repulsion is present in small atom of fluorine

Topic: Chemistry, p Block Elements (Group 15, 16, 17 & 18), NEET, NEET 2006
Which one of the following orders is not in accordance with the property stated against it ?

Options:
A F 2 >Cl 2 >Br 2 >I 2 : Bond dissociation energy
B F 2 >Cl 2 >Br 2 >I 2 : Oxidising power
C HI>HBr>HCl>HF: Acidic property in water
D F 2 >Cl 2 >Br 2 >I 2 : Electronegativity

The correct answer is:
F 2 >Cl 2 >Br 2 >I 2 : Bond dissociation energy

Solution:
Bond energy â Bond strength
Bond strength â overlapping â 1/Energy Level
F - F Cl - Cl Br - Br I - I
2p-2p 3p-3p 4p-4p 5p-5p

So, the order of bond energy should be
F 2 >Cl 2 >Br 2 >I 2
But in case of the lower value of bond dissociation energy of fluorine is due to the high inter-electronic repulsions between non-bonding electrons in the 2p- orbitals of fluorine. As a result, FâF bond is weaker in comparison to ClâCl and BrâBr bonds. So, the correct order of bond dissociation energy is Cl 2 >Br 2 > F 2 >I 2 . S
oxidising character order is same as SRP value. F 2 >Cl 2 >Br 2 >I 2
HI>HBr>HCl>HF acidic character
acidic character â stability of conjugate base (Anion)
Small size atom has more electron density. So less stable hence less acidic.
F>Cl>Br>I electronegativity on moving left to right in a period, the tendency to gain electron increases to get inert gas configuration.

Topic: Chemistry, p Block Elements (Group 15, 16, 17 & 18), NEET
Which one of the following orders of acid strength is correct?

Options:
A $\mathrm{RCOOH}>\mathrm{ROH}>\mathrm{HOH}>\mathrm{HC} \equiv \mathrm{HC}$
B $\mathrm{RCOOH}>\mathrm{HOH}>\mathrm{ROH}>\mathrm{HC} \equiv \mathrm{CH}$
C $\mathrm{RCOOH}>\mathrm{HOH}>\mathrm{HC} \equiv \mathrm{CH}>\mathrm{ROH}$
D $\mathrm{RCOOH}>\mathrm{HC} \equiv \mathrm{CH}>\mathrm{HOH}>\mathrm{ROH}$

The correct answer is:
$\mathrm{RCOOH}>\mathrm{HOH}>\mathrm{ROH}>\mathrm{HC} \equiv \mathrm{CH}$

Solution:
Carboxylic acids are most acidic and alcohols are least acidic. Phenols are more acidic than alcohols but less acidic than carboxylic acids or carbonic acid. Thus, acidic strength order is
\(\mathrm{R}-\underset{\underset{}{||} \atop \LARGE {\mathrm{O}}}{\mathrm{C}}-\mathrm{OH}>\mathrm{H}-\mathrm{O}-\mathrm{H}>\mathrm{R}-\mathrm{O}-\mathrm{H}>\mathrm{H}-\mathrm{C} \equiv \mathrm{C}-\mathrm{H}\)
Related Theory
Acid strength increases with :
1. increasing electronegativity of the central atom: The more electronegative the central atom, the more electron drift occurs, polarizing the $\mathrm{O}-\mathrm{H}$ bond which makes it easier for the molecule to dissociate.
2. increasing oxidation number of the central atom: The higher the oxidation state of the central atom, the greater the number of oxygens attached to the central atom. Oxygen is a highly electronegative element, contributing to greater electron drift away from the $\mathrm{O}-\mathrm{H}$ bond.

Topic: Chemistry, General Organic Chemistry, NEET, NEET 2003
Which one of the following ores is best concentrated by froth–floatation method?

Options:
A Cassiterite
B Galena
C Malachite
D Magnetite

The correct answer is:
Galena

Solution:
Froth–floatation is used to concentrate sulphide ores [Galena (PbS)].Cassiterite SnO2 and Magnetite Fe3O4 are oxide ores and Malachite CuOH2.CuCO3 is carbonate ore.

Topic: Chemistry, General Principles and Processes of Isolation of Metals, NEET
Which one of the following organelle in the figure correctly matches with its function?

Options:
A Rough endoplasmic reticulum, formation of glycoproteins
B Golgi apparatus, protein synthesis
C Golgi apparatus, formation of glycolipids
D Rough endoplasmic reticulum, protein synthesis

The correct answer is:
Rough endoplasmic reticulum, protein synthesis

Solution:
Rough Endoplasmic Reticulum (RER) Protein synthesis
Smooth Endoplasmic Reticulum (SER) Lipid synthesis.
Golgi apparatus - Important site of formation glycoproteins and glycolipids.

Topic: Biology, Cell - The Unit of Life, NEET, NEET 2013 (All India)
Which one of the following organelle in the figure CORRECTLY matches with its functions?

Options:
A Golgi apparatus, protein synthesis
B Golgi apparatus, formation of lipids
C Rough endoplasmic reticulum, protein synthesis
D Rough endoplasmic reticulum, formation of lipids

The correct answer is:
Rough endoplasmic reticulum, protein synthesis

Solution:
Endoplasmic reticulum is a network of tubular structures present in the cytoplasm which divide the intracellular space into luminal and extra luminal. These ER can be divided into two types depending upon the presence of ribosome on their outer surface. The rough endoplasmic reticulum (RER) has ribosomes on the outer surface while the smooth endoplasmic reticulum (SER) lacks presence of ribosomes. RER is involved in protein synthesis and secretion where as SER is involved in synthesis of lipids and lipid like hormones.

Topic: Biology, Cell - The Unit of Life, NEET
Which one of the following organism is not an obligate aerobe?

Options:
A Psuedomonas aeruginosa
B Klebsiella pneumoniae
C Mycobacterium tuberculosis
D Bacillus sp

The correct answer is:
Klebsiella pneumoniae

Solution:
Klebsiella pneumoniae is a Gram-negative, enteric bacterium which is non-motile, encapsulated, lactose-fermenting (produces acid and gas from lactose), facultative anaerobic, oxidase-negative, rod-shaped bacterium.

Topic: Biology, Biological Classification, NEET
Which one of the following organism possesses characteristics of both a plant and an animal?

Options:
A

Mycoplasma

B

Paramecium

C

Bacteria

D

Euglena

The correct answer is:

Euglena

Solution:
The Euglena is an organism, which possesses both the characteristics of plants and animals, as it can move with a flagella and also contains chlorophyll. Its nutrition is mixotrophic.

Topic: Biology, Biological Classification, NEET
Which one of the following organisms bears hollow and pneumatic long bones?

Options:
A Neophron
B Hemidactylus
C Macropus
D Ornithorhynchus

The correct answer is:
Neophron

Solution:
Birds have remarkably specialized bones that are pneumatic because they are full of air sacs that provide a continuous flow of breath throughout their bodies. Also, it is one of the flight adaptations of the birds besides, lack of urinary bladder and boat-shaped body etc. E.g. Neophron (Vulture)

Topic: Biology, Animal Kingdom, NEET, NEET 2021
Which one of the following organisms has a role in converting ammonia into nitrites?

Options:
A Rhizobium
B Nitrobacter
C Nitrosomonas
D Pseudomonas

The correct answer is:
Nitrosomonas

Solution:
Ammonia is converted into nitrate by nitrifying activities of bacteria, this process is called nitrification. Soil bacteria such as Nitrosomonas and Nitrosococcus convert ammonia to nitrite.
NH3+3O2 â2HNO2+2H2O

Topic: Biology, Mineral Nutrition, NEET
Which one of the following organisms is correctly matched with its three characteristics?

Options:
A Pea : C3 pathway, endospermic seed, vexillary aestivation
B Tomato : twisted aestivation, axile placentation, berry
C Onion : bulb, imbricate aestivation, axile placentation
D Maize : C3 pathway,closed vascular bundles scutellum

The correct answer is:
Onion : bulb, imbricate aestivation, axile placentation

Solution:
Pea is an example of having non-endospermic seed. Tomato flower has valvate aestivation where the margins of adjacent petals or sepals touch each other without overlapping. In maize, the C4 pathway is observed. Onion forms bulb with imbricate aestivation and axile placentation.

Topic: Biology, Morphology of Flowering Plants, NEET
Which one of the following organisms is not an example of a unicellular eukaryote?

Options:
A Euglena
B Gonyaulax
C Amoeba
D E. coli

The correct answer is:
E. coli

Solution:
Euglena, Gonyaulax, and Amoeba are all unicellular eukaryotes. E. coli is unicellular prokaryotic bacterial cells.

Topic: Biology, Biological Classification, NEET
Which one of the following organisms is not an example of eukaryotic cells?

Options:
A Escherichia coli
B Euglena viridis
C Amoeba proteus
D Paramecium caudatum

The correct answer is:
Escherichia coli

Solution:
The bacterium $E$. coll is a prokaryote.

Topic: Biology, Biological Classification, NEET, NEET 2011 (Screening)
Which one of the following organs in the human body is most affected due to shortage of oxygen?

Options:
A

Lungs

B

Heart

C

Kidney

D

Brain

The correct answer is:

Brain

Solution:
Brain is the most vital organ. It stops functioning in the absence of O2.

Topic: Biology, Breathing and Exchange of Gases, NEET
Which one of the following organs in the human body is most affected due to shortage of oxygen?

Options:
A Intestine
B Skin
C Kidney
D Brain

The correct answer is:
Brain

Solution:
Brain is the most vital organ. It stops functioning in the absence of O2. The brain consumes the most oxygen in the body with 18.4%, and the heart 11.6% and the liver consumes 20.4%. The low oxygen environment immediately effects the body's oxygen transport system.

Topic: Biology, Breathing and Exchange of Gases, NEET