datavorous/entrance-exam-dataset huggingface dataset:
Which one of the following hydrolyses internal phosphodiester bonds in a polynucleotide chain?

Options:
A lipase
B protease
C endonuclease
D exonuclease.

The correct answer is:
endonuclease

Solution:
DNAase (or deoxyribonuclease) or simply nuclease is an enzyme which breaks down DNA by hydrolysis of the phosphodiester bonds of its sugarphosphate back bone. Depending on the position of hydrolyzing phosphodiester bonds, nucleases are of two types: (i) Endonucleases (ii) Exonucleases. Endonucleases hydrolyse internal phosphodiester bonds in a polynucleotide chain (.i.e., DNA). While exonucleases hydrolyse terminal phosphodiester bonds in a polynucleotide chain (.i.e., DNA).

Topic: Biology, Biomolecules (B), NEET, NEET 2005
Which one of the following hydrolyses internal phosphodiester bonds in a polynucleotide chain?

Options:
A Lipase
B Protease
C Endonuclease
D Exonuclease

The correct answer is:
Endonuclease

Solution:
Endonucleases hydrolyse internal phosphodiester bonds in a polynucleotide chan (i.e. DNA) While exonucleases hydrolyse terminal phosphodiester bonds in a polynucleotide chain (i.e., DNA)

Topic: Chemistry, Biomolecules, NEET
Which one of the following immune system components does not correctly match with its respective role?

Options:
A Interferons - secreted by virus infected cells and protects non - infected cells from further viral infection
B B-lymphocytes - produce antibodies into blood in response to pathogens to fight with them
C Macrophages - mucus secreting cells that trap microbes entering in the body
D IgA - present in colostrum in early days of lactation to protect infant from diseases

The correct answer is:
Macrophages - mucus secreting cells that trap microbes entering in the body

Solution:
Macrophages are phagocytic cells that can ingest pathogenic micro-organisms. Macrophages are among the first cells that respond to the infection.

Topic: Biology, Human Health and Diseases, NEET
Which one of the following in birds, indicates their reptilian ancestry?

Options:
A Scales on their hind limbs
B Four chambered heart
C Two special chambers crop and gizzard in their digestive tract
D Eggs with a calcareous shell

The correct answer is:
Scales on their hind limbs

Solution:
The dry skin of reptiles is covered with scales to prevent water loss as an adaptation to terrestrial life. The hind limbs of birds also have scales, which confirm their reptilian ancestry.

Topic: Biology, Evolution, NEET, NEET 2008 (Screening)
Which one of the following includes all homologous organs?

Options:
A The wing of butterfly, wing of bird, wing (patagia) of bat
B The fore limb of frog, wing of bird and fore limb of rabbit
C The thoracic leg of cockroach, the hind leg of frog and fore leg of rabbit
D The wing of bird, wing of bat and wing of "flying" lizard

The correct answer is:
The fore limb of frog, wing of bird and fore limb of rabbit

Solution:
Homologous organs are the organs having similar structural plan and origin but performing different functions. Analogous organs perform a similar function but have different structural and developmental origin, e.g., wings of birds, bats and insects are analogous organs.

Topic: Biology, Evolution, NEET
Which one of the following ion exhibits d-d transition and paramagnetism as well?

Options:
A MnO4-
B Cr2O72-
C CrO42-
D MnO42-

The correct answer is:
MnO42-

Solution:
As d-d transition and paramagnetism is possible in presence of unpaired e- , so here MnO42- shows it.
CrO42-⇒Cr6+=[Ar]
Unpaired electron (n) = 0; Diamagnetic
Cr2O72-⇒Cr6+=[Ar]
Unpaired electron (n) = 0; Diamagnetic
MnO42-=Mn6+=[Ar]3d1
Unpaired electron (n) = 1; Paramagnetic
MnO4-=Mn7+=[Ar]3d0
Unpaired electron (n) = 0; Diamagnetic

Topic: Chemistry, Coordination Compounds, NEET
Which one of the following ion is aromatic?

Options:
A
B
C
D

The correct answer is:

Solution:
Here it is aromatic as it has 2 π electrons i.e., follow Huckel's Rule.
anti aromatic.
and are non-aromatic.

Topic: Chemistry, General Organic Chemistry, NEET
Which one of the following ionic species will impart colour to an aqueous solution?

Options:
A Ti4+
B Cu+
C Zn2+
D Cr3+

The correct answer is:
Cr3+

Solution:
Here Cr3+ is coloured while rest other ions are coloureless.
Ti4+=[Ar]4s03d0 (0 unpaired e- )
Cu+=[Ar]4s03d10 (0 unpaired e- )
Zn2+=[Ar]4s03d10 (0 unpaired e- )
Cr3+=[Ar]4s03d3 (3 unpaired e- )

Topic: Chemistry, Coordination Compounds, NEET
Which one of the following ions exhibits d-d transition and paramagnetism as well?

Options:
A MnO4-
B Cr2O72-
C CrO42-
D MnO42-

The correct answer is:
MnO42-

Solution:
CrO4-2Cr+6diamagnetic
Cr2O7-2Cr+6diamagnetic
MnO4-Mn+7diamagnetic
MnO4-2Mn+6Paramagnetic
Unpaired electron is present so d-d transition is possible.

Topic: Chemistry, Coordination Compounds, NEET, NEET 2018
Which one of the following ions has electronic configuration [Ar]3d6 ?
(At. nos. Mn = 25, Fe = 26, Co = 27, Ni = 28)

Options:
A Co3+
B Ni3+
C Mn3+
D Fe3+

The correct answer is:
Co3+

Solution:
In case of Co+3[Ar]3d6 configuration is possible 27Co→[Ar]3d74s2
On removing 3e- we get Co3+→[Ar]3d6

Topic: Chemistry, d and f Block Elements, NEET
Which one of the following ions has electronic configuration $[\mathrm{Ar}] 3 \mathrm{~d}^6$ ?
(At. no: $\mathrm{Mn}=25, \mathrm{Fe}=26, \mathrm{Co}=27, \mathrm{Ni}=28$ )

Options:
A $\mathrm{Ni}^{3+}$
B $\mathrm{Mn}^{3+}$
C $\mathrm{Fe}^{3+}$
D $\mathrm{Co}^{3+}$

The correct answer is:
$\mathrm{Co}^{3+}$

Solution:
Key Idea Write the electronic configurations of given ions and find the correct answer.
$$
\begin{aligned}
\mathrm{Ni}^{3+}(28) & =[\mathrm{Ar}] 3 \mathrm{~d}^7 \\
\mathrm{Mn}^{3+}(25) & =[\mathrm{Ar}] 3 \mathrm{~d}^4 \\
\mathrm{Fe}^{3+}(26) & =[\mathrm{Ar}] 3 \mathrm{~d}^5 \\
\mathrm{Co}^{3+}(27) & =[\mathrm{Ar}] 3 \mathrm{~d}^6
\end{aligned}
$$

Topic: Chemistry, Structure of Atom, NEET, NEET 2010 (Screening)
Which one of the following ions has the highest magnetic moment?

Options:
A Mn2+
B Zn2+
C Ca2+
D K+

The correct answer is:
Mn2+

Solution:
Mn2+ has 5 unpaired electrons in the 3d-sub-shell; whereas Zn2+,Ca2+ and K+ ions have all the electrons paired and, therefore, are diamagnetic. Magnetic moment depends upon the number of unpaired electrons. The more the number of unpaired electrons in an atom or ion, the greater is its magnetic moment. Thus, Mn2+ has the highest magnetic moment.

Topic: Chemistry, Coordination Compounds, NEET
Which one of the following ions has the highest value of ionic radius?

Options:
A B3+
B O2-
C Li+
D F-

The correct answer is:
O2-

Solution:
All the ions belongs to same period thus for them cations will be smaller than anions as during cation formation outer orbit is lost and effective nuclear charge increases so size decreases.
O2- and F- are isoelectronic and rn∝1Z
So ionic radius of
O2-Z=8>F-Z=9>Li+Z=3>B3+Z=5

Topic: Chemistry, Classification of Elements and Periodicity in Properties, NEET
Which one of the following ions is the most stable in aqueous solution?
(At No. $\mathrm{Ti}=22, \mathrm{~V}=23, \mathrm{Cr}=24, \mathrm{Mn}=$ 25)

Options:
A $\mathrm{V}^{3+}$
B $\mathrm{Ti}^{3+}$
C $\mathrm{Mn}^{3+}$
D $\mathrm{Cr}^{3+}$

The correct answer is:
$\mathrm{V}^{3+}$

Solution:
In aqueous solution the configuration of the ions are following
$\begin{aligned}
\mathrm{Cr}^{3+}(21) & =3 d^3 4 s^0 \Rightarrow t_{2 g}{ }^3 e_g^0 \\
\mathrm{~V}^{3+}(20) & =3 d^2 4 s^0 \Rightarrow t_{28}{ }^2 e_g^0 \\
\mathrm{Tr}^{3+}(19) & =3 d^1 4 s^0 \Rightarrow t_{28}{ }^1 e_g^0 \\
\mathrm{Mn}^{3+}(22) & =3 d^4 4 s^0 \Rightarrow t_{2 g}{ }^4 e_g^0
\end{aligned}$
We know that half-filled and fully filled orbitals are more stable than partially filled orbitals. Hence among the given ions the only $\mathrm{Cr}^{3+}$ ion which occupies half-filled $t_{2 g}$ orbitals.
Caution
Although $\mathrm{Mn}^{3+}$ ion has half-filled $t_{\text {s orbital }}$ but there is one more electron filled in $e_R$ orbital which reduces the stability.

Topic: Chemistry, d and f Block Elements, NEET, NEET 2007
Which one of the following ions will give a coloured solution?

Options:
A Cu+
B Fe2+
C Zn2+
D Ag+

The correct answer is:
Fe2+

Solution:
Since Fe2+ has unpaired electrons so, d-d transitions would take place and hence, its solution would be coloured.
Cu+→3d10
Fe2+→3d6
Zn2+→3d10
Ag+→4d10

Topic: Chemistry, Coordination Compounds, NEET
Which one of the following is a case of wrong matching?

Options:
A Somatic hybridization - Fusion of two diverse cells
B Vector DNA - Site for tRNA synthesis
C Micropropagation - In vitro production of plants in large numbers
D Callus - Unorganized mass of cells produced in tissue culture

The correct answer is:
Vector DNA - Site for tRNA synthesis

Solution:
A vector is a DNA molecule used as a vehicle to transfer foreign genetic material into desired cell.
the tRNA is synthesized in the nucleus on a DNA tempelate. Only $0.025 \%$ of total DNA content codes for tRNA.

Topic: Biology, Biotechnology - Principles and Processes, NEET, NEET 2012 (Screening)
Which one of the following is a chain growth polymer?

Options:
A Starch
B Nucleic acid
C Polystyrene
D Protein

The correct answer is:
Polystyrene

Solution:
Polystyrene is an addition polymer that results when styrene monomers interconnect (polymerization). In the polymerization, the carbon-carbon $\pi$ bond of the vinyl group is broken and a new carbon-carbon $\sigma$ bond is formed, attaching to the carbon of another styrene monomer to the chain.
Related Theory
In chain growth, the polymer chain always grows one monomer at a time. In step growth, the polymer chain doubles with each step. As a result, the rate of growth of the polymer chain is very different in these two cases. Chain growth results in a steady increase in chain length with every coupling step.

Topic: Chemistry, Polymers, NEET, NEET 2004
Which one of the following is a chain growth polymer?

Options:
A Starch
B Nucleic acid
C Polystyrene
D Protein

The correct answer is:
Polystyrene

Solution:
Chain-growth polymers involve a series of reactions each of which consume a reactive particle and produces another similar one. The reactive particles may be free radicals or ions (cations or anion) to which monomers get added by a chain reaction. It is an important reaction of alkenes and conjugated dienes or indeed of all kinds of compounds that contains C-C double bonds.

Topic: Chemistry, Polymers, NEET
Which one of the following is a characteristic feature of cropland ecosystem?

Options:
A Absence of soil organisms
B Least genetic diversity
C Absence of weeds
D Ecological succession

The correct answer is:
Least genetic diversity

Solution:
Cropland ecosystem has same type of crop plants so it has the least genetic diversity. Cropland includes areas used for the production of adapted crops for harvest.

Topic: Biology, Ecosystem, NEET, NEET 2016 (Phase 1)
Which one of the following is a copolymer?

Options:
A Buna-S
B Polyvinyl chloride
C Polypropylene
D Poly-cis-isoprene

The correct answer is:
Buna-S

Solution:
Polymers whose repeating units are derived from two or more types of monomer units, are called copolymer. Only Buna-S is obtained by the copolymerization of butadiene and styrene monomers. Other polymers B, C and D are homopolymers, because they consist of only one type of monomers.

Topic: Chemistry, Polymers, NEET
Which one of the following is a correct option with reference to pathogenic bacteria and DDT?

Options:
A Bacteria can undergo multiplication and DDT is degraded by living cells
B Bacteria can be degraded by living cells and DDT can not be degraded by living cells.
C Bacteria can undergo biological magnification and DDT can be degraded by living cells.
D Bacteria can undergo biological magnification and DDT can not be degraded by living cells.

The correct answer is:
Bacteria can be degraded by living cells and DDT can not be degraded by living cells.

Solution:
Bacteria is a prokaryotic organism and biodegradable while DDT is a non-biodegradable pollutant and undergo biological magnification.

Topic: Biology, Environmental Issues, NEET
Which one of the following is a correct set?

Options:
A H2O, sp3, angular
B H2O,Â sp2, linear
C NH4+,Â dsp2, square planar
D CH4,Â dsp2, tetrahedral

The correct answer is:
H2O, sp3, angular

Solution:
H2O has sp3-hybridisation and is angular in shape.

Topic: Chemistry, Chemical Bonding and Molecular Structure, NEET
Which one of the following is a CORRECT statement?

Options:
A "Bt" in "Bt-cotton" indicates that it is a genetically modified organism produced through biotechnology.
B Somatic hybridization involves the fusion of two complete plant cells carrying desired genes.
C RNAi takes place in all eukaryotic organisms as a method of cellular defense.
D Golden rice is vitamin C enriched rice.

The correct answer is:
RNAi takes place in all eukaryotic organisms as a method of cellular defense.

Solution:
The "Bt " in BT cotton stands for Bacillus thuringiensis, which is a soil bacterium.
Somatic hybridization is the process in which the protoplasts of two different plant species fuse to form hybrids.
Enhanced nutritional value of food, e.g., golden rice, i.e., Vitamin ‘A’ enriched rice.

Topic: Biology, Biotechnology and Its Applications, NEET
Which one of the following is a correct statement?

Options:
A Dominant trait can be expressed in homozygous condition only
B Recessive condition is expressed in homozygous condition only
C Dominant condition cannot be expressed in heterozygous condition
D All of the above

The correct answer is:
Recessive condition is expressed in homozygous condition only

Solution:
Alleles produce the opposite and contrasting phenotypes. When two alleles of a gene are identical, they are homozygous, can be either dominant (AA, BB) or recessive (aa, bb) and when two different alleles, the individual is heterozygous and are made up of one dominant and one recessive allele (Aa, Bb). In heterozygous condition, the dominant allele is able to express and the recessive allele is hidden and the recessive condition is expressed in homozygous condition only.

Topic: Biology, Principles of Inheritance and Variation, NEET
Which one of the following is a correct statement?

Options:
A "Bt" in "Bt-cotton" indicates that it is a genetically modified organism produced through biotechnology.
B Somatic hybridization involves fusion of two complete plant cells carrying desired genes.
C The transgenic Brassica napus seeds are used for production of antibiotics.
D "FlavrSavr" variety of tomato has enhanced the production of ethylene which improves its taste.

The correct answer is:
Somatic hybridization involves fusion of two complete plant cells carrying desired genes.

Solution:
Bt in Bt cotton stands for Bacillus thuringienesis and is a pest-resistant transgenic plant. The transgenic Brassica napus seeds are a source of hirudin which is used as an anti-blood coagulating substance. Flavr savr tomato is a transgenic plant in which the shelf-life of tomato is increased by inhibiting the production of fruit ripening hormone polygalacturonase using the mRNA silencing technique. Somatic hybridization is a cull fusion technique involving the fusion of two complete plant cells carrying desired genes.

Topic: Biology, Biotechnology and Its Applications, NEET
Which one of the following is a correct statements?

Options:
A Pteridophyte gametophyte has a protonemal and leafy stage
B In gymnosperms female gametophyte is free-living
C Antheridiophores and archegoniophores are present in pteridophytes
D Origin of seed habit can be traced in pteridophytes

The correct answer is:
Origin of seed habit can be traced in pteridophytes

Solution:
Some pteridophytes like Selaginella and Salvinia are heterosporous as they produce two kinds of spores micro (small) spores and macro (large) spores, which germinate and give rise to male and female gametophyte respectively. The female gametophyte in these plants are retained on the parent sporophytes for variable periods. The development of the zygotes into young embryos takes place within the female gametophyte. This event is the precursor to the seed habit, considered to an important step in evolution.

Topic: Biology, Plant Kingdom, NEET, NEET 2012 (Screening)
Which one of the following is a fatsoluble vitamin and its related deficiency disease?

Options:
A retinol - xerophthalmia
B cobalamine - beri-beri
C calciferol - pellagra
D ascorbic acid - scurvy.

The correct answer is:
retinol - xerophthalmia

Solution:
Xerophthalmia is a vitamin A (retinol) deficiency disorder which is caused by stoppage of lacrimal activity. Cornea and eye lids become dry and ulcerated. It leads to swelling of dry eye lids and opacity of cornea. Xerophthalmia, if untreated, leads to blindness. Scurvy is vitamin C deficiency disease, Beri beri is vitamin \(B_1\) deficiency disease and Pellagra is caused due to deficiency of niacin.

Topic: Biology, Biomolecules (B), NEET, NEET 2007
Which one of the following is a free radical substitution reaction?

Options:
A

B

C

D $\mathrm{CH}_3 \mathrm{CHO}+\mathrm{HCN} \rightarrow \mathrm{CH}_3 \mathrm{CH}(\mathrm{OH}) \mathrm{CN}$

The correct answer is:

Solution:
Related Theory
Alkanes can be converted to Haloalkanes through a free radical substitution as free radicals are highly reactive.
Caution
Free radicals are formed if a bond splits evenly - each atom getting one of the two electrons. The name given to this is homolytic fission.

Topic: Chemistry, Hydrocarbons, NEET, NEET 2003
Which one of the following is a hallucinogenic drug?

Options:
A Caffeine
B Morphine
C Lysergic acid diethylamide
D Opium

The correct answer is:
Lysergic acid diethylamide

Solution:
LSD is a psychedelic drug causing optical and auditory hallucination and induces behavioural abnormalities. Opium and morphine are opiate narcotics and acts as depressants and analgesic. Caffeine is a stimulant.
Related Theory
Drug addiction can be due to - Stress, Curiosity, Peer pressure, To overcome frustrations and depressions, etc.

Topic: Biology, Human Health and Diseases, NEET, NEET 2013 (Karnataka)
Which one of the following is a matching pair of a body feature and the animal possessing it?

Options:
A Ventral heart-scorpion
B Post-anal tail-octopus
C Ventral central nervous system-leech
D Pharyngeal gill slits absent in embryo-Chameleon

The correct answer is:
Ventral heart-scorpion

Solution:
Leech is an Annelida, and has ventral central nervous system which consists of nerve ring, and a solid, double, mid ventral nerve cord with ganglia.
Chameleon is a reptile, possessing pharyngeal gill slits during its embryonic development, and are later replaced by lungs. Scorpion is an Arthropoda, having dorsal heart. Octopus, a mollusc do not possess post anal tail. It is a characteristic feature of mammals.
Related Theory
The arthropod nervous system consists of a dorsal brain and a ventral, ganglionated longitudinal nerve cord (primitively paired) from which lateral nerves extend in each segment. The system is similar to that of annelid worms, from which arthropods may have evolved.

Topic: Biology, Animal Kingdom, NEET, NEET 2007
Which one of the following is a matching pair of a body feature and the animal possessing it?

Options:
A Pharyngeal gill slits absent during embryonic development - Chameleon
B Ventral heart - Scorpion
C Post-anal tail - Octopus
D Ventral central nervous system - Leech

The correct answer is:
Ventral central nervous system - Leech

Solution:
The ventral nerve cord is found in insects and is functionally equivalent to the vertebrate spinal cord. This kind of nervous system is found in leeches and some of the annelids and arthropods. The scorpion possesses a dorsal heart, Post anal tail is usually seen in cobras belonging to the phylum Chordata. Pharyngeal gill slits are found in the embryos of all vertebrates due to their common ancestors, the fish, who were the first one to have these structures.

Topic: Biology, Animal Kingdom, NEET
Which one of the following is a matching pair of an animal and a certain win phenomenon it exhibits?

Options:
A Pheretima - Sexual dimorphism
B Musca - Complete metamorphosis
C Chameleon - Mimicry
D Taenia - Polymorphism

The correct answer is:
Musca - Complete metamorphosis

Solution:
Complete metamorphosis is a phenomenon by which a larva after moulting several times changes into an adult form. The life cycle of Musca includes four stages-egg, larva, pupa and adult.
Pheretima is bisexual, having both male and female reproductive organs.
Chameleon shows camouflage.
Taeniadoes not show polymorphism.
Related Theory
In complete metamorphosis, larva after hatching, moults several times to become a fully grown one. It later becomes a pupa within a secreted case, called the puparium. Pupa differentiates into the young adult that breaks the puparium open and emerges outside. Then it grows to a mature form.

Topic: Biology, Animal Kingdom, NEET, NEET 2003
Which one of the following is a matching pair of certain organisms and the kind of association?

Options:
A Shark and sucker fish - ammensalism
B Algae and fungi in lichens - mutualism
C Orchids growing on tress - mutualism
D Cuscuta (dodder) growing on other flowering plants - epiphytism

The correct answer is:
Algae and fungi in lichens - mutualism

Solution:
The association between fungi and algae in lichen is regarded as the true mutual relationship, in which both the partners are benefitted. In lichen, fungus lives on the algae which manufactures food by virtue of the chlorophyll present in its cells, while the algae enjoys the protection afforded by the fungal envelope, to live in very dry conditions.

Topic: Biology, Organisms and Populations, NEET
Which one of the following is a matching pair of certain organism(s) and the kind of association between them?

Options:
A Algae and fungi in lichens - Mutualism
B Shark and sucker fish - Ammensalism
C Orchids growing on trees - Parasitism
D Cuscuta (dodder) growing on other-flowering plants - Epiphytism

The correct answer is:
Algae and fungi in lichens - Mutualism

Solution:
In a lichen thallus, algae and fungi show mutualism. Fungi provide fixation, water, minerals and shelter to the algae. The algae manufactures food for itself and for fungi.
Suckerfish and shark show commensalism as there is no negative interaction between the two. The same type of relationship is seen between orchids growing on trees. Cuscuta is a parasite and thus exhibit parasitism while growing on other plants.

Topic: Biology, Organisms and Populations, NEET
Which one of the following is a matching pair of certain organism(s) and the kind of association?

Options:
A Sea anemone and clownfish - Commensalism
B Red algae and fungi in liches - Mutualism
C Orchids growing on trees - Parasitism
D Cuscuta (dodder) growing on other flowering plants - Epiphysis

The correct answer is:
Sea anemone and clownfish - Commensalism

Solution:
A classic example of commensalism is observed in the interaction between a sea anemone that has stinging tentacles and the clownfish that lives among them. The fish gets protection from predators which stay away from the stinging tentacles. The anemone does not appear to derive any benefit by hosting the clownfish.

Topic: Biology, Organisms and Populations, NEET