datavorous/entrance-exam-dataset huggingface dataset:
Which molecule, water (H2O) or dimethyl ether (CH3OCH3), has a greater bond angle?

Options:
A Water, because it has a greater electronegativity difference between the central atom and surrounding atoms.
B Dimethyl ether, because it has a smaller electronegativity difference between the central atom and surrounding atoms.
C Water, because it has fewer surrounding atoms bonded to the central atom.
D Dimethyl ether, because it has more surrounding atoms bonded to the central atom.

The correct answer is:
Water, because it has a greater electronegativity difference between the central atom and surrounding atoms.

Solution:
Correct Option is : (A)
Water, because it has a greater electronegativity difference between the central atom and surrounding atoms.

Topic: Chemistry, Chemical Bonding and Molecular Structure, NEET
Which molecules are responsible for synthesizing proteins in a cell?

Options:
A Carbohydrates
B Lipids
C RNA
D DNA

The correct answer is:
RNA

Solution:
While DNA contains the genetic information, various RNA molecules are responsible for the actual synthesis of proteins in a cell.

Topic: Chemistry, Biomolecules, NEET
Which monosaccharide units are present in starch, cellulose and glucose and which linkages link these units?

Options:
A In starch,cellulose and glycogen, glycosidic α-linkage is present
B In starch and glycogen, glycosidic α-linkage is present and in cellulose, glycosidic β-linkage is present between glucose units.
C In starch,cellulose and glycogen, glycosidic β-linkage is present
D None of the above

The correct answer is:
In starch and glycogen, glycosidic α-linkage is present and in cellulose, glycosidic β-linkage is present between glucose units.

Solution:
Correct Option is : (B)
In starch and glycogen, glycosidic α-linkage is present and in cellulose, glycosidic β-linkage is present between glucose units.

Topic: Chemistry, Biomolecules, NEET
Which monoxide among CO, GeO, SnO, and PbO is neutral in nature?

Options:
A CO
B GeO
C SnO
D PbO

The correct answer is:
CO

Solution:
CO is neutral among the monoxides.

Topic: Chemistry, p Block Elements (Group 13 & 14), NEET
Which monoxide is amphoteric in nature?

Options:
A CO
B GeO
C SnO
D PbO

The correct answer is:
SnO

Solution:
SnO is amphoteric among the monoxides.

Topic: Chemistry, p Block Elements (Group 13 & 14), NEET
Which named reaction is used to convert amides into amines

Options:
A Curtius raction
B Claisen condensation
C Hoffmann reaction
D Schimidt reaction

The correct answer is:
Hoffmann reaction

Solution:
Hofmann’s bromamide reaction
CH3-CO-NH2Acetamide+Br2+4KOH→H2O
CH3NH2Methylamine+K2CO3+2KBr+2H2O

Topic: Chemistry, Amines, NEET
Which nitrogenous base is common for both DNA and RNA?

Options:
A Adenine
B Guanine
C Cytosine
D Uracil

The correct answer is:
Cytosine

Solution:
Cytosine is common for both DNA and RNA.

Topic: Biology, Molecular Basis of Inheritance, NEET
Which nitrogenous base is present in RNA in place of Thymine?

Options:
A Adenine
B Guanine
C Cytosine
D Uracil

The correct answer is:
Uracil

Solution:
Uracil is present in RNA at the place of Thymine.

Topic: Biology, Molecular Basis of Inheritance, NEET
Which noble gas has a different electronic configuration than the others?

Options:
A Neon
B Argon
C Helium
D Krypton

The correct answer is:
Helium

Solution:
Helium has a different electronic configuration (1s^2) compared to the other noble gases (ns^2 np^6).

Topic: Chemistry, p Block Elements (Group 15, 16, 17 & 18), NEET
Which noble gas has a similar electronic configuration to hydrogen?

Options:
A Helium (He)
B Neon (Ne)
C Argon (Ar)
D Krypton (Kr)

The correct answer is:
Helium (He)

Solution:
The paragraph states that hydrogen's electronic configuration (1s1) resembles that of helium (1s2).

Topic: Chemistry, Hydrogen, NEET
Which noble gas has the highest ionization energy?

Options:
A Xenon
B Neon
C Helium
D Krypton

The correct answer is:
Helium

Solution:
Helium has the highest ionization energy among the noble gases.**

Topic: Chemistry, p Block Elements (Group 15, 16, 17 & 18), NEET
Which noble gas has the lowest boiling point among all known substances?

Options:
A Argon
B Neon
C Krypton
D Helium

The correct answer is:
Helium

Solution:
Helium has the lowest boiling point (4.2 K) of any known substance.

Topic: Chemistry, p Block Elements (Group 15, 16, 17 & 18), NEET
Which noble gas was used by Neil Bartlett to prepare the first compound of a noble gas?

Options:
A Argon
B Krypton
C Xenon
D Radon

The correct answer is:
Xenon

Solution:
Neil Bartlett used xenon to prepare the first compound of a noble gas, Xe+PtF6⁻.

Topic: Chemistry, p Block Elements (Group 15, 16, 17 & 18), NEET
Which noble gases combine with oxygen and fluorine to form compounds?

Options:
A Helium and neon
B Argon and neon
C Xenon and krypton
D Radon and argon

The correct answer is:
Xenon and krypton

Solution:
Noble gases like xenon and krypton combine with oxygen and fluorine to form compounds.

Topic: Chemistry, Chemical Bonding and Molecular Structure, NEET
Which noble gases have a particularly stable outer shell configuration of eight (octet) electrons?

Options:
A All noble gases
B Helium only
C Noble gases except helium
D Noble gases except neon

The correct answer is:
Noble gases except helium

Solution:
Kössel notes that all noble gases have stable outer shell configurations, but helium is the exception, having a duplet (two electrons) in its outer shell.

Topic: Chemistry, Chemical Bonding and Molecular Structure, NEET
Which noble gases occur in the Earth's atmosphere?

Options:
A All noble gases except radon and oganesson
B Only argon
C All noble gases except xenon and krypton
D None of the noble gases are found in the atmosphere

The correct answer is:
All noble gases except radon and oganesson

Solution:
All noble gases except radon and oganesson occur in the Earth's atmosphere.

Topic: Chemistry, p Block Elements (Group 15, 16, 17 & 18), NEET
Which nomenclature is not according to IUPAC system?

Options:
A

B

C

D

The correct answer is:

Solution:
In IUPAC system of nomenclature, preference is given to multiple bond than halogen substituent, so the correct name of $\mathrm{Br}-\stackrel{3}{\mathrm{CH}_2}-\stackrel{2}{\mathrm{CH}}=\stackrel{1}{\mathrm{CH}_2}$ is 3-bromoprop-1-ene

Topic: Chemistry, General Organic Chemistry, NEET, NEET 2012 (Screening)
Which notation is used to express the oxidation number of a metal in a compound, as described by Alfred Stock?

Options:
A Lewis notation
B Stock notation
C Bohr notation
D Dalton notation

The correct answer is:
Stock notation

Solution:
The passage refers to the notation given by Alfred Stock as "Stock notation."

Topic: Chemistry, Redox Reactions, NEET
Which of following are the steps of genetic engineering?

Options:
A Isolation of DNA
B Fragmentation of DNA by restriction endonuclease.
C Isolation of the desired DNA fragments.
D All of these

The correct answer is:
All of these

Solution:
Genetic engineering: It is manipulation of genetic material which can be added or detected through their bases or parts of DNA to introduce these into host organisms and thereby change the phenotype of the host organism.

The steps of genetic engineering are

(i) Isolation of DNA.

(ii) Separation by gel electrophoresis.

(iii) Isolation of the desired DNA fragments.

(iv) Amplification of the gene of interest.

(v) Ligation of the DNA fragment into a vector using DNA Ligase.

(vi) Transfer of recombinant DNA into the host organism.

(vii) Culturing the host cell on a suitable medium on a large scale.

(viii) Extraction of the desired product.

(ix) Downstream processing of the products as finished products is ready for marketing.

Topic: Biology, Biotechnology - Principles and Processes, NEET
Which of following coordinate complexes is an exception to EAN rule?
(Given Atomic number Pt = 78, Fe = 26, Zn = 30, Cu = 29)

Options:
A [Pt(NH3)6]4+
B [Fe(CN)6]4-
C [Zn(NH3)4]2+
D [Cu(H2O)4]2+

The correct answer is:
[Cu(H2O)4]2+

Solution:
As in [Cu(H2O)4]2+ EAN is 35, so it does not follow EAN rule.
EAN = Atomic number of central atom + Number of electrons donated by ligands – oxidation state of central atom.
(A) [Pt(NH3)6]4+ EAN =78+2×6-4=86
(B) [Fe(CN)6]4- EAN =26+1×6+4=36
(C) [Zn(NH3)4]2+ EAN =30+2×4-2=36
(D) [Cu(H2O)4]2+ EAN =29+2×4-2=35

Topic: Chemistry, Coordination Compounds, NEET
Which of following gates produces output of 1?

Options:
A
B
C
D

The correct answer is:

Solution:
Output of circuit ( B ) is, 0.0 ¯ = 0 ¯ =1

Topic: Physics, Semiconductors, NEET
Which of following order is correct-

Options:
A Deuterium>Hydrogen(Enthalpy of fusion)
B Hydrogen>Deuterium(Enthalpy of bond dissociation)
C Deuterium>Hydrogen(Enthalpy of vaporisation)
D a and c both

The correct answer is:
a and c both

Solution:
Correct Option is : 4
a and c both

Topic: Chemistry, Hydrogen, NEET
Which of following represents the correct order of covalent character among the iodides of alkali metals?

Options:
A LiI > NaI > KI > RbI > CsI
B NaI > KI > RbI > CaI > LiI
C LiI > CsI > RbI > KI > NaI
D CsI > RbI > KI > NaI > LiI

The correct answer is:
LiI > NaI > KI > RbI > CsI

Solution:
Extent of polarization decreases with increasing in size of cation. Extent of polarization is maximum in LiI and minimum in CsI. Hence, LiI has maximum covalent character while CsI has minimum covalent character.
LiI > NaI > KI > RbI > CsI

Topic: Chemistry, Chemical Bonding and Molecular Structure, NEET
Which of following statement is incorrect regarding mitochondria?

Options:
A Matrix possesses single ds circular DNA molecule and ribosomes of 70S type.
B Site of aerobic and anaerobic respiration
C Outer membrane forms the continuous limiting boundrary of the organelle, while inner membrane is folded into cristae.
D Mitochondria divide by fission like division to increases its number.

The correct answer is:
Site of aerobic and anaerobic respiration

Solution:
Mitochondria is the site for aerobic respiration only. Glycolysis is the common step for aerobic and anaerobic respiration which occurs in the cytoplasm. Further, anaerobic respiration occurs in the cytoplasm and the aerobic respiration occurs in the mitochondria with the release of carbon dioxide by utilizing oxygen.

Topic: Biology, Respiration in Plants, NEET
Which of following statements is false?

Options:
A Increase of pressure of a gas causes the amount of adsorption to increase
B Increase of temperature may increase or decrease the amount of adsorption
C The adsorption may be monolayer or multilayer
D Particle size of the adsorbent does not affect the amount of adsorption

The correct answer is:
Particle size of the adsorbent does not affect the amount of adsorption

Solution:
As particle size increases amount of adsorption decreases.

Topic: Chemistry, Surface Chemistry, NEET
Which of following trihalides of nitrogen behaves as the weakest base?

Options:
A NF3
B NCl3
C NBr3
D NI3

The correct answer is:
NF3

Solution:
Among trihalides of nitrogen given here NF3 behaves as the weakest base because of high electronegativity of F atom, the nitrogen atom attains positive charge and therefore, it has practically no electron-donating properties.

Topic: Chemistry, p Block Elements (Group 15, 16, 17 & 18), NEET
which of the above statements are correct?
Extraction of metal from the ore cassiterite involves
(1) Self- reduction of a sulphide ore
(2) Carbon reduction of an oxide are
(3) Removal of iron impurity
(4) Removal of copper impurity

Options:
A 1,3,4
B 2,3,4
C 2,3
D 3,4

The correct answer is:
2,3,4

Solution:
The ore cassiterite contains the impurity of Fe,Mn,W and traces of Cu so removal of Fe and Cu etc are needed hence 3 and 4 are correct. As it is reduced by carbon reduction method so 2 is correct and 1 is wrong.
SnO2+2C→2CO+Sn

Topic: Chemistry, General Principles and Processes of Isolation of Metals, NEET
Which of the alkali metal chloride ( $\mathrm{MCl})$ forms its dihyrate salt $\left(\mathrm{MCl} \cdot 2 \mathrm{H}_2 \mathrm{O}\right)$ easily?

Options:
A $\mathrm{LiCl}$
B $\mathrm{CsCl}$
C $\mathrm{RbCl}$
D $\mathrm{KCl}$

The correct answer is:
$\mathrm{LiCl}$

Solution:
The size of the ion and its charge determines extent of hydration. Greater the charge and smaller the size of ion, greater is the extent of hydration and hence greater is the hydration enthalpy. Thus, $\mathrm{Li}^{+}$having maximum hydration tendency forms dihydrate salt $\left(\mathrm{LiCl}_2 2 \mathrm{H}_2 \mathrm{O}\right)$ easily.

Topic: Chemistry, s Block Elements, NEET, NEET 2019 (Odisha)
Which of the alkali metals form complex hydrides?

Options:
A Li
B Na
C K
D Both A and B

The correct answer is:
Both A and B

Solution:
Both Li and Na form complex hydrides, LiAlH4 and NaBH4 .
2MH+B2H6→2M+[BH4]-
(M = Li or Na)

Topic: Chemistry, s Block Elements, NEET
Which of the alkali metals has the least melting point?

Options:
A Na
B K
C Rb
D Cs

The correct answer is:
Na

Solution:
Correct Option is : (A)
Na

Topic: Chemistry, s Block Elements, NEET
Which of the alkaline earth metal halides given below is essentially covalent in nature?

Options:
A BeCl2
B MgCl2
C SrCl2
D CaCl2

The correct answer is:
BeCl2

Solution:
Be2+ cation is very small in size and in terms of Fajan's rules brings about polarization of electronic cloud of anion (Cl-) i.e. BeCl2 is covalent in nature.

Topic: Chemistry, s Block Elements, NEET
Which of the aromatic compounds react fastest with methoxide ion?

Options:
A
B
C
D

The correct answer is:

Solution:
A nitro from para position activate more for SNAr reaction due to electron withdrawing resonance effect than two nitro from meta position by inductive effect (-I).

Topic: Chemistry, Haloalkanes and Haloarenes, NEET
Which of the aromatic compounds react fastest with methoxide ion?

Options:
A
B
C
D

The correct answer is:

Solution:
A nitro from para position activate more for SNAr reaction due to electron withdrawing resonance effect than two nitro from meta position by inductive effect.

Topic: Chemistry, Haloalkanes and Haloarenes, NEET
Which of the arrangement of meninges is correct (inside to outside)?

Options:
A Duramater → arachnoid membrane → piamater
B Duramater → piamater → arachnoid membrane
C Piamater â arachnoid membrane â duramater
D Arachnoid membrane → duramater → piamater

The correct answer is:
Piamater â arachnoid membrane â duramater

Solution:
Meninges are the connective tissue membrane which protects the central nervous system and projections of its structure. These membranes are piamater (thinnest), arachnoid (thin, webbly and slightly vascular), and duramater (the outermost double layered, thick and nonvascular).

Topic: Biology, Neural Control and Coordination, NEET
Which of the below mentioned regions exhibit less seasonal variations?

Options:
A Tropics
B Temperates
C Alpines
D Both

The correct answer is:
Tropics

Solution:
Tropical regions exhibit less seasonal variations.

Topic: Biology, Biodiversity and its Conservation, NEET
Which of the below-mentioned regions exhibit less seasonal variations?

Options:
A Tropics
B Temperates
C Alpines
D Both A and B

The correct answer is:
Tropics

Solution:
The region near the middle of the Earth between the Tropic of Cancer and Tropic of Capricorn is considered as the Tropic region. This region receives the most amount of solar energy which leads to better productivity and higher species diversity. Tropical forests are the landscape within the north and south of and near equator and show less seasonal variations compared to other regions.
Below image describes the requirement of MAP and MAR of different forest types.

Topic: Biology, Ecosystem, NEET
Which of the comformers of n - butane has maximum potential energy?

Options:
A Anti
B Gauche
C Fully eclipsed
D Eclipsed

The correct answer is:
Fully eclipsed

Solution:
In fully eclipsed confirmation, repulsion is maximum so it has maximum energy also but least stability.
The decreasing order of energy or increasing order of stability for various conformations of butane is as follows
Fully eclipsed, Eclipsed, Gauche, Anti

Topic: Chemistry, General Organic Chemistry, NEET
Which of the components of human semen are correctly matched with the glands that secrete it?

(i) Citric acid - Prostate gland

(ii) Fibrinogen - Seminal vesicle

(iii) Prostaglandins - Prostate gland

(iv) Fructose - Seminal vesicle

Options:
A i, ii, iii and iv
B ii, iii and iv
C ii and iv
D i, ii and iv

The correct answer is:
i, ii and iv

Solution:
Fluid from Seminal vesicle contains fructose, vitamin C, prostaglandins and fibrinogen. Fructose is a seminal fluid that provides energy to sperms. Prostaglandins increase the mobility of sperms and stimulate vaginal contractions, which help the infusion of gametes. Fibrinogen helps in the coagulation of semen after ejaculation. The prostatic fluid contains lipids citric acid, enzyme acid phosphatase and proteolytic enzymes. Proteolytic enzymes help in liquefaction of semen.

Topic: Biology, Human Reproduction, NEET
Which of the compounds shown below will react with diethyl malonate in the presence of methoxide ion to give a compound, which on treatment with aqueous acid and gentle heating will decarboxylate to form butanoic acid?

Options:
A
B CH3CH2Br
C
D CH3CH2CH2Br

The correct answer is:
CH3CH2Br

Solution:
Here ethyl bromide reacts with diethyl malonate and the reaction is as follows

Topic: Chemistry, Carboxylic Acid Derivatives, NEET
Which of the compounds will react faster in SN1 reaction with the OH-ion? CH3— CH2— Cl or C6H5— CH2— Cl

Options:
A CH3—CH2—Cl
B C6H5—CH2—Cl
C Both react at the same rate towards SN1 reaction
D None of them undergo SN1 reaction

The correct answer is:
C6H5—CH2—Cl

Solution:
Correct Option is : (B)
C6H5—CH2—Cl

Topic: Chemistry, Haloalkanes and Haloarenes, NEET
Which of the compounds with molecular formula $\mathrm{C}_5 \mathrm{H}_{10}$ yields acetone on ozonolysis?

Options:
A 3-Methyl-l-butene
B Cyclopentane
C 2-Methyl-1-butene
D 2-Methyl-2-butene

The correct answer is:
2-Methyl-2-butene

Solution:
2-methyl-2-butene (molecular formula \(\mathrm{C}_5 \mathrm{H}_{10}\)) yields acetone on ozonolysis.
Related Theory
Ozone is a very reactive allotrope of oxygen. The reaction of ozone with alkenes and alkynes causes the oxidative cleaving of the alkene or alkyne. The carbon-carbon triple bonds are replaced with carbon-oxygen double bonds, giving the required carbonyl product

Topic: Chemistry, Hydrocarbons, NEET, NEET 2007
Which of the contraceptive release mineral ions to inhibit the motility of a sperm?

Options:
A Condoms
B Copper T
C Saheli
D Norplant

The correct answer is:
Copper T

Solution:
Copper ions are toxic for the sperm and prevent its motility so that it cannot fertilize eggs.

Topic: Biology, Reproductive Health, NEET
Which of the curve shows, how oxygen is loaded and unloaded due to partial pressure?

Options:
A O2 Curve
B CO2 Curve
C Bohr’s curve
D O2 Dissociation curve

The correct answer is:
Bohr’s curve

Solution:
The oxygen-haemoglobin dissociation curve under normal conditions is sigmoid shaped. The lower part of the curve indicates dissociation of oxygen from haemoglobin, whereas the upper part indicates the acceptance of oxygen by haemoglobin.

The shifting of oxygen-haemoglobin dissociation curve to the right by carbon dioxide partial pressure increasing is known as Bohr effect.

Topic: Biology, Breathing and Exchange of Gases, NEET
Which of the elements possess the highest oxidation state?

Options:
A Mn
B Cr
C Pt
D Os

The correct answer is:
Os

Solution:
Correct Option is : 4
Os

Topic: Chemistry, d and f Block Elements, NEET
Which of the events listed below is not observed during mitosis?

Options:
A Chromatin condensation
B Movement of centrioles to opposite poles
C Appearance of chromosomes with two chromatids joined together at the centromere
D Crossing over

The correct answer is:
Crossing over

Solution:
Crossing over occurs in pachytene (it is a phase of meiosis-I). Crossing over is the exchange of genetic material (genes) between two homologous chromosomes.

Topic: Biology, Cell Cycle and Cell Division, NEET
Which of the fact is not due to surface tension

Options:
A dancing of a camphor piece over the surface of water
B small mercury drop itself becomes spherical
C a liquid surface comes at rest after stirring
D mercury does not wet the glass vessel

The correct answer is:
a liquid surface comes at rest after stirring

Solution:
A liquid surface comes at rest after stirring due to viscosity.
Rest are examples of surface tension.

Topic: Physics, Mechanical Properties of Fluids, NEET
Which of the following 0.1 M complex compound solutions will have the minimum electrical conductivity?

Options:
A [Pt N H 3 3 C l 3 ]Cl
B [Pt N H 3 4 C l 2 ]C l 2
C [Pt N H 3 5 Cl]C l 3
D Hexaammine platinum(iv) chloride

The correct answer is:
[Pt N H 3 3 C l 3 ]Cl

Solution:
Ionic conductivity depends upon the number of ions produced in aqueous solution. Less no. of ions produced, lower is the electrical conductivity. So, triamminetrichlorido platinum (IV) chloride has the minimum electrical conductivity.

Topic: Chemistry, Coordination Compounds, NEET
Which of the following absorb light energy for photosynthesis?

Options:
A Chlorophyll
B Water molecule
C $\mathrm{O}_2$
D RUBP

The correct answer is:
Chlorophyll

Solution:
Chlorophyll molecule absorbs light for photosynthesis. $\mathrm{H}_2 \mathrm{O}$ molecules provide $\mathrm{H}^{+}$ions and electrons during photosynthesis. $\mathrm{O}_2$ is liberated during photosynthesis. RuBP (Ribulose 1, 5-bisphosphate) reacts with $\mathrm{CO}_2$ during dark reaction of photosynthesis. This process takes place in the presence of enzyme RuBisCO.

Topic: Biology, Photosynthesis in Higher Plants, NEET, NEET 2002
Which of the following accessory gland is not paired?

Options:
A Seminal vesicle
B Prostate gland
C Bulbourethral gland
D None of these

The correct answer is:
Prostate gland

Solution:
The male accessory glands include paired seminal vesicles, a prostate and paired bulbourethral glands. Secretions of these glands constitute the seminal plasma which is rich in fructose, calcium and certain enzymes. The secretions of bulbourethral glands also helps in the lubrication of the penis.

Topic: Biology, Human Reproduction, NEET
Which of the following accounts for 50% of the total cost of various ecosystem services?

Options:
A Soil formation
B Nutrient cycling
C Climate regulation
D Recreation and habitat for wild life

The correct answer is:
Soil formation

Solution:
As per ecological economist Robert Constanza, soil formation accounts for about 50%, and contributions of other services like recreation and nutrient cycling are less than 10% each from the total cost of various ecosystem services. Climate regulation and habitat for wildlife each cost approximately 6%.

Topic: Biology, Ecosystem, NEET
Which of the following acid will form an
(a) Anhydride on heating and
(b) Acid imide on strong heating with ammonia?

Options:
A
B
C
D

The correct answer is:

Solution:

Topic: Chemistry, Carboxylic Acid Derivatives, NEET, NEET 2020 (Phase 2)
Which of the following acids dissolves lead most readily to give clear solution?

Options:
A Acetic acid
B Hydrochloric acid
C Sulphuric acid
D Nitric acid

The correct answer is:
Nitric acid

Solution:
Both HCl and H2SO4 do react with Pb but form insoluble PbCl2 and PbSO4 . Out of CH3COOH and HNO3,HNO3 reacts more readily.

Topic: Chemistry, p Block Elements (Group 15, 16, 17 & 18), NEET
Which of the following acids does not exhibit optical isomerism?

Options:
A Maleic acid
B $\alpha$-amino acids
C Lactic acid
D Tartaric acid

The correct answer is:
Maleic acid

Solution:
Only those compounds exhibit optical isomerism, which have chiral centre and/or absence of symmetry elements. (Chiral carbon is the carbon all the four valencies of which are satisfied by four different groups.)
(a)
(b)
(c)
(d)
Thus, maleic acid does not exhibit optical isomerism.
Note If $R=H$, the $\alpha$-amino acid is achiral.

Topic: Chemistry, General Organic Chemistry, NEET, NEET 2012 (Screening)