datavorous/entrance-exam-dataset huggingface dataset:
E.coli cells with a mutated z gene of the lac operon cannot grow in medium containing only lactose as the source of energy because:

Options:
A The lac operon is constitutively active in these cells
B They cannot synthesize functional Beta galactosidase
C In the presence of glucose, E.coli do not utilize lactose
D They cannot transport lactose from the medium into the cell

The correct answer is:
They cannot synthesize functional Beta galactosidase

Solution:
Operons are segments of genetic material which function as regulated unit or units that can be switched on and switched off. An operon consists of one to several structural genes. (Three in lac operon) these are genes which produce mRNAs for forming polypeptides / proteins/enzymes. Z (produces enzyme Î² galactosidase for splitting lactose into glucose and galactoside). Y ( produces enzyme galactoside permease required in the entry of lactose ) A (produces enzyme thiogalactoside transacetylase). The three structural genes of the operon produce a single polycistronic mRNA.

Topic: Biology, Molecular Basis of Inheritance, NEET
E.coli with completely N15 DNA was allowed to replicate in N14 medium for two generations. Percentage of bacteria with heavy DNA will be

Options:
A 6.25%
B 50%
C 25%
D 100%

The correct answer is:
50%

Solution:
Meselson and Stahl found that DNA of the first generation of bacteria was hybrid or intermediate (N15 N14). The second generation of bacteria, after 40 minutes, contained two types of DNA, 50% light (N14 N14) and 50% intermediate (N14 N15). The third generation of bacteria after 60 minutes contained two types of DNA, 25% intermediate (N15 N14) and 75% light (N14 N14) in 1:3 ratio. The fourth-generation after 80 minutes contained 12.5% N15 N14 and 87.5% N14N14 DNA in a 1:7 ratio.

Topic: Biology, Molecular Basis of Inheritance, NEET
Ecological niche is

Options:
A the sum total of environmental factors or conditions, which determine the existence of organism, population, or community in a particular locality.
B an ecologically adapted zone and is the address of an organism
C the physical position and functional role of a species within the community
D formed of all plants and animals living at the bottom of a lake

The correct answer is:
the physical position and functional role of a species within the community

Solution:
The place and function of a species/organism in its environment are termed as an ecological niche. The ecological niche is about the species interaction with its environment to meets its requirement of resources. It also describes the response of organism to the different resources in the surrounding. Species niche is about interactions between the biotic and abiotic factors in the particular region. An ecological niche refers to animal's place in the biotic environment and its relation to its food and enemies or its functional role in an ecosystem.

Topic: Biology, Organisms and Populations, NEET
Ecological pyramids are of

I. three types (age pyramids, energy pyramids and biomass pyramids).
II. four types (age pyramids, energy pyramids, number pyramids and biomass pyramids).
III. five types ((age pyramids, energy pyramids, number pyramids, tropical pyramids and biomass pyramids).

Select the statements with the correct option.

Options:
A I, II and II
B I and II
C I only
D None are correct

The correct answer is:
None are correct

Solution:
Three types of ecological pyramid are present, and they are: the pyramid of the number, pyramid of biomass and pyramid of energy.

Topic: Biology, Ecosystem, NEET
Ecological succession is

Options:
A Directional but unpredictable.
B Directional and predictables.
C Gradual and predictable.
D Directionless and unpredictable.

The correct answer is:
Gradual and predictable.

Solution:
The gradual and fairly predictable changes that occur in a species till a climax stage develops which does not change further because it is in perfect harmony with the environment is called ecological succession.

Topic: Biology, Ecosystem, NEET
Ecologically, the most important factor that controls the distribution of organism on Earth is

Options:
A Rainfall
B Temperature
C Light
D Humidity

The correct answer is:
Temperature

Solution:
Ecologically temperature is most important factor because it controls distribution of organism on earth. On the basis of temperature tolerance, both plants and animals show a distribution pattern on earth. Temperature affects all physiological functions of organisms through its effect on enzyme activity.

Topic: Biology, Organisms and Populations, NEET
EcoRI always cut DNA molecules at a particular point by recognizing a specific sequence between:

Options:
A G and A
B T and C
C A and A
D T and T

The correct answer is:
G and A

Solution:
Restriction enzymes, also called restriction nucleases (EcoRI in this example), surrounds the DNA molecule at the point it seeks (sequence GAATTC). EcoRI cuts one strand of the DNA double helix at one point and the second strand at a different, complementary point (between the G and the A base).

Topic: Biology, Biotechnology - Principles and Processes, NEET
EcoRI always cuts DNA molecules at a particular point by recognizing a specific restriction sequence, the sticky ends formed after digestion have the sequence

Options:
A AATTC
B TCCCA
C AACTT
D TTCAC

The correct answer is:
AATTC

Solution:
Restriction enzymes, also called restriction nucleases (EcoRI in this question), surround the DNA molecule at the recognition point (sequence GAATTC for EcoRI). EcoRI cuts one strand of the DNA double helix at one point and the second strand at the complementary point (between the G and A base).

Topic: Biology, Biotechnology - Principles and Processes, NEET
Ecotone is:

Options:
A A polluted area
B The bottom of a lake
C A zone of developing community
D A zone of transition between two communities

The correct answer is:
A zone of transition between two communities

Solution:
A community of organisms interacting with an abiotic components in a particular region/area will be called an ecosystem. Various groups of interacting organisms in a particular region are included in community. There are various types of ecosystems like terrestrial, aquatic etc. The region or habitat which integrates two different ecosystems together is said to be an ecotone. Ecotone forms the transition region between two different biological communities or ecosystems.

Topic: Biology, Organisms and Populations, NEET
Ectopic pregnancies are referred to as :

Options:
A Implantation of embryo at site other than uterus
B Implantation of defective embryo in the uterus
C Pregnancies terminated due to hormonal imbalance
D Pregnancies with genetic abnormality.

The correct answer is:
Implantation of embryo at site other than uterus

Solution:
Any extra-uterine pregnancy is known as ectopic pregnancy. Implantation can occur in the wall of abdominal cavity and ovaries, but 90-95% of ectopic pregnancies are tubal pregnancy, where implantation occurs in the fallopian tube.

Topic: Biology, Reproductive Health, NEET, NEET 2015 (Phase 2)
Edaphic factor refers to:

Options:
A Water
B Soil
C Relative humidity
D Altitude

The correct answer is:
Soil

Solution:
factors related to soil or known as Edaphic factors.

Topic: Biology, Ecosystem, NEET
Edge length of cube is 300 pm. Its body diagonal would be

Options:
A 600 pm
B 423 pm
C 519.6 pm
D 450.5 pm

The correct answer is:
519.6 pm

Solution:
Length of body diagonal
= 3  × edge length of the cube (a)
=â 3 âÃâ300âpmâ=â1.732âÃâ300
â=â519.6âpm

Topic: Chemistry, Solid State, NEET
Edible part in mango is:

Options:
A mesocarp
B epicarp
C endocarp
D epidermis

The correct answer is:
mesocarp

Solution:
In mango, pericarp is differentiated into the exocarp, mesocarp and endocarp. Exocarp is form the outer covering of the fruit. Mesocarp is the edible part of the mango and is hard and stony (seed).

Topic: Biology, Morphology of Flowering Plants, NEET, NEET 2002
Edible part of mango is:

Options:
A endocarp
B receptacle
C epicarp
D mesocarp.

The correct answer is:
mesocarp.

Solution:
In mango, pericarp is differentiated into the exocarp, mesocarp and endocarp. Exocarp is form the outer covering of the fruit. Mesocarp is the edible part of the mango and is hard and stony (seed).

Topic: Biology, Morphology of Flowering Plants, NEET, NEET 2004
Effect on the genetic drift is minimized if

Options:
A Population is large
B Emigrating individuals are large in number
C Emigration occurs frequently
D Large segment of a population dies

The correct answer is:
Population is large

Solution:
Genetic drift:
If the change in gene frequency occurs by chance, it is called genetic drift. Sometimes the genetic drift is so prominent in the new sample of the population that newly formed population may become a different species. In this case, the original drifted population is termed as founders and the effect is called the founder effect. When there are fewer copies of an allele, larger is the genetic drift and when there is more number of copies, the effect is minimized.
Bottleneck effect - Bottlenecks are natural calamities like earthquakes, volcanic eruptions, earthquakes or storms, etc. sudden change in the environment may drastically reduce the size of the population and now this population may be genetically different from the original population. Certain alleles may have more frequency among the survivors, others may be less and some may be absent altogether. In a population that has passed through a bottleneck ultimately recovers in size, but it may have low levels of genetic variations for a long period of time and this may produce a new species.

Topic: Biology, Evolution, NEET
Effective atomic number (EAN) of Mn in Mn 2 (CO) 10 is

Options:
A 36
B 35
C 72
D 40

The correct answer is:
36

Solution:
In Mn 2 (CO) 10 , there is one MnâMn bond
Electron present in 2 Mn = 50
Electrons donated by 10 CO = 20
Electrons in one Mn−Mn bond = 2
Total electrons = 72
So EAN per Mn=722=36 .

Topic: Chemistry, Coordination Compounds, NEET
Effective nuclear charge (Zeff) for a nucleus of an atom is defined as

Options:
A shielding of the outermost shell electrons from the nucleus by the innermost shell electrons
B the net positive charge experienced by electron from the nucleus
C the attractive force experienced by the nucleus from electron
D screening of positive charge on nucleus by innermost shell electrons

The correct answer is:
the net positive charge experienced by electron from the nucleus

Solution:
Effective nuclear charge is the net positive charge experienced by the electrons from the nucleus. Due to presence of electrons in the innermost shells the electrons in the outermost shell do not experience the full positive charge from the nucleus. This is known as shielding of the outermost shell electrons from the nucleus by the innermost shell electrons.

Topic: Chemistry, Classification of Elements and Periodicity in Properties, NEET
Effectiveness of different wavelength of light on photosynthesis is measured by

Options:
A Quantum yield
B Quantum requirement
C Absorption spectrum
D Fluorescence

The correct answer is:
Absorption spectrum

Solution:
Absorption of different wavelength of light by different pigment is variable, and each pigment absorbs different wavelength differently. The absorption of light of different wave length by different pigment is called absorption spectrum which mediates the process of photosynthesis.

Topic: Biology, Photosynthesis in Higher Plants, NEET
Egg apparatus consists of

Options:
A egg and two synergids
B 2 eggs and 2 synergids
C 2 synergids
D egg and one synergid

The correct answer is:
egg and two synergids

Solution:
The embryo sac or female gametophyte in angiosperms is a 7 celled 8 nucleated structure. It has an egg apparatus towards the micropylar end It has a central haploid cell which is ovum or female gamete. On either sides of the eeg or ovum there is one synergid each. They have filiform apparatus which secretes a fluid which guides the pollen tube into the embryo sac. Synergids degenerate after fertilization.

Topic: Biology, Sexual Reproduction in Flowering Plants, NEET
Eight charges each of value q are placed on a ring of radius R placed in x-y plane with origin at centre. A -q charge having mass m is projected from z=∞ towards the centre of the ring with velocity v . The velocity of -q when it reaches the centre of ring is (neglect gravity)

Options:
A 8kq2mR
B 8kq2mR+v
C 16kq2mR+v2
D 16kq2mR+v

The correct answer is:
16kq2mR+v2

Solution:
Potential at the center Vc=-k(8q)R
Ui+Ki=Uf+Kf
0+12mv2=qVc+12mv′2
0+12mv2=-k8q2R+12mv′2
â´Â Â v′=16kq2mR+v2

Topic: Physics, Electrostatics, NEET
Eight resistances each of resistance 5 Î© are connected in the circuit as shown in the figure. The equivalent resistance between A and B is â

Options:
A 8 3 Î©
B 1 6 3 Ω
C 1 5 7 Ω
D 1 9 2 Ω

The correct answer is:
8 3 Î©

Solution:
From the symmetry current in AO will be same as current in OB
Simiarly current CO equal to current in OD
The given circuit can be redrawn as

1 R AB = 1 40 3 + 1 10 + 1 5
â´ R AB = 8 3 Î©

Topic: Physics, Current Electricity, NEET
Eight resistances each of resistance 5 Î© are connected in the circuit as shown in the figure. The equivalent resistance between A and B is

Options:
A 83 Ω
B 163 Ω
C 157 Ω
D 192 Ω

The correct answer is:
83 Ω

Solution:
The given circuit can be redrawn as
∴RAB=83 Ω

Topic: Physics, Current Electricity, NEET
Einstein's photoelectric equation states that Ek=hν-W . In this equation, Ek refers to

Options:
A kinetic energy of all ejected electrons
B mean kinetic energy of emitted electrons
C minimum kinetic energy of emitted electrons
D maximum kinetic energy of emitted electrons

The correct answer is:
maximum kinetic energy of emitted electrons

Solution:
Ek refers to maximum kinetic energy of emitted electrons. The energy of photon absorbed is used in doing work against forces of attraction and imparting kinetic energy to electron.

Topic: Chemistry, Structure of Atom, NEET
Elaioplasts store

Options:
A fats
B starch
C proteins
D essential amino acids

The correct answer is:
fats

Solution:
Plastids are found in plant cells. These consist of pigments. Based on the type of pigments, these are further classified as chloroplasts, chromoplasts and leucoplasts. Chloroplasts contain chlorophyll, which brings about photosynthesis. Chromoplasts contain colored pigments like carotenes, xanthophylls, etc. This is responsible for the colored part of the plant. Leucoplasts are colorless plastids and contain stored nutrients. These can be amyloplasts if they store carbohydrates. This is seen in potatoes etc. elaioplasts store oils, fats and aleuroplasts contain proteins.

Topic: Biology, Cell - The Unit of Life, NEET
Elbow joint is an example of

Options:
A pivot joint
B hinge joint
C gliding joint
D ball and socket joint

The correct answer is:
hinge joint

Solution:
In hinge joint, the convex surface of one bone fits into the concave surface of another bone. eg, knee, elbow and interphalangeal joints.
Pivot joint, one bone is fixed and second articulated, eg, atlas and axial of skull rotate with axis vertebra.
Gliding joints primarily permit side-by-side and back-and-forth gliding movements, eg, intercarpal joints and intertarsal joints.
In ball and socket joint, ball of one bone articulates in socket of another bone, eg, head of humerus and glenoid cavity of pectoral girdle.

Topic: Biology, Locomotion and Movement, NEET, NEET 2009 (Screening)
Elbow, knee, finger joints, toe joints, ankles are good examples for

Options:
A Saddle joint
B Hinge joint
C Gliding joint
D Pivot joint

The correct answer is:
Hinge joint

Solution:
The hinge joint is a type formed between bones where they can move in only one plane. Hinge joints permit uniaxial movements like flexion-extension and resemble the movements of a door or window. Humerus and ulna make the elbow joint which allows the flexion and extension of the forearm relative to the upper arm. In the elbow joint the ulna works like a hinge, so only forward movement is possible. In the knee joint, the patella or knee cap works as a hinge so only backward movement is possible.

Topic: Biology, Locomotion and Movement, NEET
Electric charge q is uniformly distributed over a rod of length l. The rod is placed parallel to a long wire carrying a current i. The separation between the rod and the wire is a. Find the force needed to move the rod along its length with a uniform velocity v.

Options:
A μ0iqv2πa
B μ0qv3πa2
C μ0q2v2πa2
D μ0ivq3πa

The correct answer is:
μ0iqv2πa

Solution:
F = I â B = Î» vLB
F = q vB
F = qv Î¼ 0 4 Ï 2 i a = Î¼ 0 iqv 2 Ï a

Topic: Physics, Magnetic Effects of Current, NEET
Electric displacement is given by D=ÎµE, here, Îµ=electric permittivity, E=electric field strength
The dimensions of electric displacement are

Options:
A [ML-2TA]
B [L-2T-1A]
C [L-2TA]
D None of these

The correct answer is:
[L-2TA]

Solution:
Electric displacement, D=εE
Unit of D=C2Nm2NC
∴ D=Cm2=[AT][L2]=[L-2TA]

Topic: Physics, Units and Dimensions, NEET
Electrically, an isolated p-type semiconductor is

Options:
A Positively charged
B Negatively charged
C Neutral
D None of the given

The correct answer is:
Neutral

Solution:
Semiconductors are made of atoms. All atoms are electrically neutral.

Mere presence of an electron or a hole doesn't make it charged as in p type or in n type semiconductor, electrons and protons are equal in number.

Topic: Physics, Semiconductors, NEET
Electrode potential data given below
Cl2+2H2O→2ClO-+4H++2e-;E°=-1.61volt
ClO-+2H2O→ClO3-+4H++4e-;E°=-0.50volt
Based on these data which is the spontaneous reaction.

Options:
A Cl2+ClO-+ClO3-
B ClO-→Cl2+ClO3-
C ClO3-→Cl2+ClO-
D ClO-+Cl2→ClO3-

The correct answer is:
ClO-→Cl2+ClO3-

Solution:
Given electron potential data is-
Cl2+2H2O→2ClO–+4H++2e–;E°=-1.61 Volt
ClO–+2H2O→ClO3–+4H++4e–;E°=-0.50 Volt
For reaction to be spontaneous E0 reaction should +ve , Thus substracting equation 1 from equation 2.

Topic: Chemistry, Electrochemistry, NEET
Electrolysis of a solution of HSO 4 - ions produces S 2 O 8 2â . Assuming 75% current efficiency, what current should be employed to achieve a production rate of 1 mol of S 2 O 8 2â per hour ?

Options:
A 71.50 A
B 35.70 A
C 142.96 A
D 285.93 A

The correct answer is:
71.50 A

Solution:
2 HSO 4 â â S 2 O 8 2â +2 H + +2 e â â
So, required rate = 1 mol/hr of S 2 O 8 2− = 2 moles of HSO 4 â
= 2 Ã 9 6 5 0 0 C 3 6 0 0 s = 2 Ã 9 6 5 3 6 A â 53.6 A
So required current = 4 3 Ã 53.6 A = 71.47 A

Topic: Chemistry, Electrochemistry, NEET
Electrolysis of an acetate solution produces ethane according to the Kolbe reaction:

2CH3COO-âC2H6+2CO2+2e-

What volume of ethane is produced at 27Â°C and 740 mm Hg , if a current of 0.5 ampere were passed through the solution for 7 hours and the electrode reaction is 82% efficient?

Options:
A 2.70 L
B 5.4 L
C 1.35 L
D 0.65 L

The correct answer is:
1.35 L

Solution:
Number of moles of e-=0.500Ã7.00Ã360096500Ã0.82=0.1071 mole
Two moles of electrons are associated with 1 mole C2H6, thus,
Volume of C2H6=0.10712Ã22.4Ã760740Ã300273=1.35 L

Topic: Chemistry, Electrochemistry, NEET
Electrolytic reduction of nitrobenzene in weakly acidic medium gives

Options:
A N-phenylhydroxylamine
B nitrosobenzene
C aniline
D p-hydroxyaniline

The correct answer is:
aniline

Solution:
Electrolytic reduction of nitrobenzene in weakly acidic medium gives aniline but in strongly acidic medium it gives p-aminophenol through the acid-catalysed rearrangement of the initially formed phenylhydroxylamine.
C6H5NO2nitrobenzene→ElectrolyticC6H5NH2Aniline

Topic: Chemistry, Amines, NEET
Electrolytic reduction of nitrobenzene in weakly acidic medium gives:

Options:
A N-phenylhydroxylamine
B nitrosobenzene
C aniline
D p-hydroxyaniline

The correct answer is:
aniline

Solution:

Topic: Chemistry, Amines, NEET, NEET 2005
Electrolytic reduction of nitrobenzene in weakly acidic medium gives

Options:
A N - phenylhydroxylamine
B Nitrosobenzene
C Aniline
D p - hydroxyaniline

The correct answer is:
Aniline

Solution:

Topic: Chemistry, Amines, NEET
Electrolytic refining is used to purify which of the following metals?

Options:
A Cu and Zn
B GeÂ andÂ Si
C ZrÂ andÂ Ti
D ZnÂ andÂ Hg

The correct answer is:
Cu and Zn

Solution:
Mostly copper Cu and zinc Zn are purified by electrolytic refining.
â´Cu and Zn is the correct option.

Topic: Chemistry, General Principles and Processes of Isolation of Metals, NEET
Electromagnetic radiation of wavelength 242 nm is just sufficient to ionise the sodium atom. Calculate the ionisation energy of sodium in kJ mol–1.

Options:
A 312 kJ mol–1
B 416 kJ mol–1
C 494 kJ mol–1
D 534 kJ mol–1

The correct answer is:
494 kJ mol–1

Solution:
Correct Option is : (C)
494 kJ mol–1

Topic: Chemistry, Structure of Atom, NEET
Electromagnetic radiations of wavelength 2000 Ã are incident on a metal surface which has a work function 5.01 eV. The stopping potential for the given setup is

Options:
A 1.19 eV
B 6.19 eV
C 3.19 eV
D 4.19 eV

The correct answer is:
1.19 eV

Solution:
Incident energy =124002000=6.2 eV
∴ K.E. = 6.2 - 5.01 = 1.19 eV
∴ Stopping potential = 1.19 eV

Topic: Physics, Dual Nature of Matter, NEET
Electromagnetic waves propagate in the direction parallel to the vector

Options:
A E →
B B →
C E → × B →
D B → × E →

The correct answer is:
E → × B →

Solution:
Electromagnetic wave propagate perpendicular to electric and magnetic field vector and in the direction parallel to E → × B →

Topic: Physics, Electromagnetic Waves, NEET
Electromagnets are made of soft iron because soft iron has

Options:
A low retentivity and high coercive force
B high retentivity and high coercive force
C low retentivity and low coercive force
D high retentivity and low coercive force

The correct answer is:
low retentivity and low coercive force

Solution:
Electromagnets are made of soft iron because soft iron has low retentivity and low coercive force or low coercivity Soft iron is a soft magnetic material.

Topic: Physics, Magnetic Properties of Matter, NEET, NEET 2010 (Screening)
Electrometallurgical process is used to extract

Options:
A Fe
B Pb
C Na
D Ni

The correct answer is:
Na

Solution:
Because Na is very reactive and can not be extracted by means of the reduction by C, CO. etc. So, it is extracted by electrolysis of molten NaCl Solution.

Topic: Chemistry, General Principles and Processes of Isolation of Metals, NEET
Electron Affinity of Cl is 3.7 eV. How much Energy released in kCal when 2g of gaseous chlorine atoms is converted to Cl- ions in the gaseous state.

Options:
A 4.80 kCal
B 5.20 kCal
C 1.50 kCal
D 3.60 kCal

The correct answer is:
4.80 kCal

Solution:
Moles of Cl(g)= 2 3 5 Â· 5 = 0.0563 mole
Energy Released,
= 0.0 5 6 3 Ã 3.7 Ã 96.5 = 20.10 kJ
= 20.10 4.1 8 4 = 4.80 kCal

Topic: Chemistry, Classification of Elements and Periodicity in Properties, NEET
Electron are accelerated through a potential difference V and protons are accelerated through a potential difference of 4 V. The de - Broglie wavelengths are Î»e and Î»p for electrons and protons, respectively. The ratio of Î»eÎ»p is given by (given, me is mass of electron and mp is mass of proton)

Options:
A λeλp=mpme
B λeλp=memp
C λeλp=12memp
D λeλp=2mpme

The correct answer is:
λeλp=2mpme

Solution:
We have, E=qV, we know that E=12mv2
âÂ Â Â v=2Em
As, Î»=hmv=hm2Em
âÂ Â Î»=h2mqV .... (i)
For electron, Î»e=h2meeV .... (ii)
For proton, Î»p=h2mpeV′Â âµq=e
â´Î»p=h2mpq.4VÂ âµV′=4V ... (iii)
On dividing equation (ii) by equation (iii), we get
Î»eÂ Î»pÂ =2mpme

Topic: Physics, Dual Nature of Matter, NEET