datavorous/entrance-exam-dataset huggingface dataset:
Which one of the following statements cannot be connected to Predation?

Options:
A It might lead to extinction of a species
B Both the interacting species are negatively impacted
C It is necessitated by nature to maintain the ecological balance
D It helps in maintaining species diversity in a community

The correct answer is:
Both the interacting species are negatively impacted

Solution:
Predation is a type of antagonistic interaction in which the predator is benefited, and the other species is harmed. This maintains ecological balance and the species diversity in the ecosystem.

Topic: Biology, Organisms and Populations, NEET, NEET 2022 (Phase 1)
Which one of the following statements for D.I. Mendeleeff, is incorrect ?

Options:
A He authored the textbook - Principles of Chemistry.
B At the time, he proposed Periodic Table of elements structure of atom was known.
C Element with atomic number 101 is named after him.
D He invented accurate barometer.

The correct answer is:
At the time, he proposed Periodic Table of elements structure of atom was known.

Solution:
At the time, he proposed the periodic table but structure of atom was unknown.

Topic: Chemistry, Classification of Elements and Periodicity in Properties, JEE Main, JEE Main 2021 (22 Jul Shift 1)
Which one of the following statements for pyramid of energy is incorrect, whereas the remaining three are correct?

Options:
A It shows energy content of different trophic level organisms
B It is inverted in shape
C It is upright in shape
D Its base is broad

The correct answer is:
It is inverted in shape

Solution:
Pyramid of energy is graphic representation of energy per unit area sequence-wise in various rising trophic levels with producers at the base and top carnivores at the apex. Pyramid of energy is upright in all the cases. It is also more accurate than other types of ecological pyramids.

Topic: Biology, Ecosystem, NEET, NEET 2011 (Screening)
Which one of the following statements is correct?

Options:
A
From a mixed precipitate of $\mathrm{AgCl}$ and $\mathrm{AgI}$, ammonia solution dissolves only $\mathrm{AgCl}$

B
Ferric ions give a deep green precipitate on adding potassium ferrocyanide solution

C
On boiling a solution having $\mathrm{K}^{+}, \mathrm{Ca}^{2+}$ and $\mathrm{HCO}_3^{-}$ions we get a precipitate of $\mathrm{K}_2 \mathrm{Ca}\left(\mathrm{CO}_3\right)_2$.

D
Manganese salts give a violet borax bead test in the reducing flame

The correct answer is:
From a mixed precipitate of $\mathrm{AgCl}$ and $\mathrm{AgI}$, ammonia solution dissolves only $\mathrm{AgCl}$

Solution:
Ammonia can dissolve ppt. of Agcl only due to formation of complex as given below:
$\mathrm{AgCl}+2 \mathrm{NH}_3 \rightarrow\left[\mathrm{Ag}\left(\mathrm{NH}_3\right)_2\right] \mathrm{Cl}$

Topic: Chemistry, General Organic Chemistry, JEE Main, JEE Main 2003
Which one of the following statements is correct?

Options:
A
All amino acids except lysine are optically active

B
All amino acids are optically active

C
All amino acids except glycine are optically active

D
All amino acids except glutamic acid are optically active

The correct answer is:
All amino acids except glycine are optically active

Solution:

Topic: Chemistry, Biomolecules, JEE Main, JEE Main 2012 (Offline)
Which one of the following statements is correct?

Options:
A endocrine glands regulate neural activity, but not vice versa
B neurons regulate endocrine activity, but not vice versa
C endocrine glands regulate neural activity, and nervous system regulates endocrine glands
D neither hormones control neural activity nor the neurons control endocrine activity

The correct answer is:
neurons regulate endocrine activity, but not vice versa

Solution:
The nervous system and endocrine system both use chemical messengers to signal cells, but each has a different transmission speed. The signals from nervous system stimulates the endocrine system, which inturn target the specific organ to function.
Related Theory
Along with the nervous system, the endocrine system coordinates the body's functions to maintain homeostasis during rest and exercise. The nervous and endocrine systems also work together to initiate and control movement, and all the physiological processes movement involves.

Topic: Biology, Neural Control and Coordination, NEET, NEET 2006
Which one of the following statements is correct?

Options:
A Cleistogamous flowers are always autogamous.
B Xenogamy occurs only by wind pollination.
C Chasmogamous flowers do not open at all.
D Geitonogamy involves the pollen and stigma of flowers of different plants.

The correct answer is:
Cleistogamous flowers are always autogamous.

Solution:
Cleistogamous flowers are the flowers which are bisexual and never opens. Xenogamy occurs by hydrophily, anemophily, entomology and other pollinating agents. Chasmogamous flowers are open flowers which shows both self-pollination and cross pollination. Geitonogamy is type of self-pollination in which pollen of one flower get deposited on the stigma of other flower belonging to same plant.
Related Theory
Sometimes bisexual flowers remain closed and never open: such flowers are called cleislogamous. In such flowers, the anthers and stigma lie close to each other. When anthers dehisce, the pollen grains come in contact with stigma and pollination takes place. Such a type of pollination occurring in closed flowers is referred as cleistogamy. e.g. Arachis hypogea (Groundnut).

Topic: Biology, Sexual Reproduction in Flowering Plants, NEET, NEET 2013 (Karnataka)
Which one of the following statements is correct?

Options:
A Hybrid orbitals do not form $\sigma$ bonds
B Lateral overlap of $p$-orbitals or $p$ - and $d$-orbitals produces $\pi$-bonds
C The strength of bonds follows the order
$$
\sigma_{p-p} < \sigma_{s-s} < \pi_{p-p}
$$
D s-orbitals do not form $\sigma$ bonds

The correct answer is:
Lateral overlap of $p$-orbitals or $p$ - and $d$-orbitals produces $\pi$-bonds

Solution:
(a) Hybridised orbitals show only head on overlapping and thus form only $\sigma$ bonds. They never form $\pi$ bonds.
(c) Head on overlapping is stronger than lateral or sideways overlapping. Therefore, the strength of bonds follows the order
$$
\underbrace{\pi_{\rho-p}}_{\begin{array}{c}
\text { lateral } \\
\text { overlapping }
\end{array}} < \underbrace{\sigma_{s-s} < \sigma_{s-p} < \sigma_{\rho-p}}_{\text {head on overlapping of same shell }}
$$
(d) s-orbitals are spherically symmetrical and thus show only head on overlapping and form only $\sigma$ bonds.

Topic: Chemistry, Chemical Bonding and Molecular Structure, JEE Main
Which one of the following statements is correct?
[AIEEE-2011, 4/120]

Options:
A All amino acids except lysine are optically active
B All amino acids are optically active
C All amino acids except glycine are optically active
D All amino acids except glutamic acids are optically active

The correct answer is:
All amino acids except glycine are optically active

Solution:
The chemical formula of amino acid is R-CH(NH2)-COOH , it consists of a basic amino group (-NH2) and an acidic carboxyl group (-COOH) along with an organic R group (side chain) which is unique in each amino acid.

Those molecules which have one chiral carbon atom will be optically active.
The structure of lysine, glycine and glutamic acid are given below-

NH2-CH2-COOH , NH2-(CH2)4-CH(NH2)COOH , HOOC-(CH2)2-CH(NH2)COOH

Only 'glycine' is optically inactive (contains two hydrogen atoms at the α-carbon) whereas all amino acids are optically active.

The remaining amino acids are optically active.

Topic: Chemistry, Biomolecules, JEE Main
Which one of the following statements is correct for electrolysis of brine solution?

Options:
A Cl2 is formed at cathode
B O2 is formed at cathode
C H2 is formed at anode
D OH-is formed at cathode

The correct answer is:
OH-is formed at cathode

Solution:
Brine solution is the concentrated solution of NaCl in water.

NaCl (aq.)→Na(aq) ++Cl(aq) +

The cathode will attract the sodium ions from the sodium chloride and hydrogen ions from the water. The hydrogen ions gain 2 electrons and are reduced to form hydrogen molecules.

2H+ (aq) + 2e- → H2 (g)

2H2O + 2e− → H2 (g) + 2OH− (aq)

The anode will attract the hydroxide ions from the water and chlorine ions from sodium chloride. The chlorine ions lose 2 electrons and get oxidised.

Cl2 → 2Cl− + 2e−

Na+ + OH− → NaOH

Topic: Chemistry, Electrochemistry, JEE Main, JEE Main 2023 (31 Jan Shift 1)
Which one of the following statements is correct for secondary succession?

Options:
A It occurs on a deforested site
B It follows primary succession
C It is similar to primary succession except that it has a relatively fast pace
D It begins on a bare rock

The correct answer is:
It occurs on a deforested site

Solution:
Secondary succession or subsere is ecological succession that takes place in a recently denuded area which still contains a lot of organic debris, remains and propagules of previously living organisms. It is more common and caused by baring of an area due to forest fires, deforestation, excessive overgrazing, landslides, earthquakes, repeated floods, etc. Only 50 to 100 years are required for establishment of a grassland over a recently denuded area. Formation of forest requires 100 to 200 years.

Topic: Biology, Ecosystem, NEET, NEET 2011 (Screening)
Which one of the following statements is correct in respect of the curve $4 \mathrm{y}-\mathrm{x}^{2}-8=0 ?$

Options:
A The curve is increasing in $(-4,4)$
B The curve is increasing in $(-4,0)$
C The curve is increasing in $(0,4)$
D The curve is decreasing in $(-4,4)$

The correct answer is:
The curve is increasing in $(0,4)$

Solution:
Given that $4 \mathrm{y}-\mathrm{x}^{2}-8=0$ $\Rightarrow \quad y=\frac{x^{2}+8}{4}$
Differentiating w.r.t. $\mathrm{x}$
$\frac{\mathrm{dy}}{\mathrm{dx}}=\frac{2 \mathrm{x}}{4}$
For increasing function
$\frac{\mathrm{dy}}{\mathrm{dx}}>0$
So, $\frac{2 x}{4}>0 \Rightarrow x>0$
Thus, the curve is increasing in $(0,4)$.

Topic: Mathematics, Application of Derivatives, JEE Main
Which one of the following statements is correct with respect to immunity?

Options:
A Preformed antibodies need to be injected to treat the bite by a viper snake
B The antibodies against small pox pathogen are produced by T-lymphocytes
C Antibodies are protein molecules, each of which has four light chains
D Rejection of a kidney graft is the function of B-lymphocytes

The correct answer is:
Preformed antibodies need to be injected to treat the bite by a viper snake

Solution:
In artificially acquired passive immunity preformed antibody in an immune serum is introduced into the body by infection. As the antivenum used to treat snake bites. In this case, the body does not produce any antibodies. Antibody is a protein molecule having two light chain and two heavy chain. B-cells recognize and bind antigens and may differentiate to memory cell or plasma cells (produce antibody). T-cells causes transplant rejection.

Topic: Biology, Human Health and Diseases, NEET, NEET 2012 (Mains)
Which one of the following statements is correct?

Options:
A Fertilization in human takes place in the womb.
B Zygote contains haploid number of chromosomes.
C Fertilization membrane avoids polyspermy.
D Primary oocyte inhibits the process of oogenesis.

The correct answer is:
Fertilization membrane avoids polyspermy.

Solution:
After the spermâs receptors come into contact with the eggâs jelly layer and the acrosomal enzymes are released and break down the jelly layer, the sperm head comes in contact with the plasma membrane of the egg. When the two plasma membranes contact one another, signals in the egg are initiated.

First, Na+ channels in the egg open, allowing Na+ to flood into the egg. This causes a depolarization of the egg from its normal resting potential of -70 mV.

While depolarization is occurring, the remainder of the jelly layer is dissolving. With the dissolution of the jelly layer and the depolarization of the plasma membrane, the first block to preventing fertilization by multiple sperm is put into place.

Within 1/10th of a second of contact, the fast block to polyspermy is initiated. The cortical granules release its secretion causing the change in the composition of the zona pellucida membrane.
Slow block:

The cortical vesicles contain enzymes that cause a number of changes to occur in the egg.

1. The eggâs sperm receptors are removed.

2. H2O is absorbed, causing the membrane to swell and push the vitelline membrane away from the plasma membrane.

3. The vitelline membrane hardens.

Topic: Biology, Human Reproduction, NEET
Which one of the following statements is false?

Options:
A
Raoult's law states that the vapour pressure of a components over a solution is proportional to its mole fraction

B
Two sucrose solutions of same molality prepared in different solvents will have the same freezing point depression

C
The correct order of osmotic pressure for $0.01 \mathrm{M}$ aqueous solution of each compound is $\mathrm{BaCl}_2>\mathrm{KCl}>\mathrm{CH}_3 \mathrm{COOH}>$ sucrose

D
The osmotic pressure $(\pi)=\mathrm{MRT}$, where $\mathrm{M}$ is the molarity of the solution

The correct answer is:
Two sucrose solutions of same molality prepared in different solvents will have the same freezing point depression

Solution:
No Solution Available

Topic: Chemistry, Biomolecules, JEE Main, JEE Main 2004
Which one of the following statements is false?

Options:
A The correct order of osmotic pressure for 0.01 M aqueous solution of each compound is $\mathrm{BaCl}_{2}>\mathrm{KCl}>\mathrm{CH}_{3} \mathrm{COOH}>$ sucrose.
B The osmotic pressure $(\pi)$ of a solution is given by the equation $\pi=\mathrm{MRT}$, where $\mathrm{M}$ is the molarity of the solution.
C Raoult's law states that the vapour pressure of a component over a solution is proportional to its mole fraction.
D Two sucrose solutions of same molality prepared in different solvents will have the same freezing point depression.

The correct answer is:
Two sucrose solutions of same molality prepared in different solvents will have the same freezing point depression.

Solution:
$\Delta \mathrm{T}_{\mathrm{f}}=\mathrm{K}_{\mathrm{f}} \times \mathrm{m} \times \mathrm{i}$. Since $\mathrm{K}_{\mathrm{f}}$ has different values
for different solvents, hence even if the $\mathrm{m}$ is the same $\Delta \mathrm{T}_{\mathrm{f}}$ will be different.

Topic: Chemistry, Solutions, JEE Main
Which one of the following statements is FALSE for hydrophilic sols?

Options:
A These sols are reversible in nature.
B Their viscosity is of the order of that of H2O.
C The sols cannot be easily coagulated.
D They do not require electrolytes for stability.

The correct answer is:
Their viscosity is of the order of that of H2O.

Solution:
Viscosity of hydrophilic sol >viscosity of H2O

Hydrophilic sol is more stable so can't be easily coagulated

Hydrophilic sols are reversible sols.

No electrolytes are required to stabilise hydrophilic sol.

Topic: Chemistry, Surface Chemistry, JEE Main, JEE Main 2021 (25 Feb Shift 2)
Which one of the following statements is incorrect?

Options:
A Primary metabolites have identifiable functions.
B Some secondary metabolites have ecological importance.
C Secondary metabolites like rubber, drugs, spices, scents and pigments are useful to human welfare.
D Secondary metabolites are not found in fungi, microbes and plants.

The correct answer is:
Secondary metabolites are not found in fungi, microbes and plants.

Solution:
Organic compounds present in living tissue are called as biomolecules. These biomolecules which are main structural and functional components of all cells are called as primary metabolites. In plant, fungal and microbial cells many other compounds like alkaloids, flavinoids, rubber, scents, gums, spices etc are present without any identifiable function, these are called as secondary metabolites.

Topic: Chemistry, Biomolecules, NEET
Which one of the following statements is incorrect?

Options:
A In amensalism one species is harmed and other is benefited.
B Commensalism is the interaction in which one species benefits and the other is neither harmed nor benefited.
C The association of cattle egret and grazing cattle is a classic example of commensalism.
D Competition occurs when closely related species complete for the same resources.

The correct answer is:
In amensalism one species is harmed and other is benefited.

Solution:
Amensalism is a type of biological association between two organisms where one of the two remains unaffected while the other is adversely affected by the relationship.
Classic example amensalism is displayed between fungus Penicillium and bacteria where Penicillium secretes antibiotic that inhibits the growth of bacteria (adversely affected) and Penicillium remains unaffected.

Topic: Biology, Organisms and Populations, NEET
Which one of the following statements is incorrect?

Options:
A The principle of countercurrent flow facilitates efficient respiration in gills of fishes
B The residual air in lungs slightly decreases the efficiency of respiration in mammals
C The presence of non-respiratory air sacs, increases the efficiency of respiration in birds
D In insects, circulating body fluids serve to distribute oxygen to tissues.

The correct answer is:
The residual air in lungs slightly decreases the efficiency of respiration in mammals

Solution:
Residual air is the air which remains in the lungs after the most forceful expiration. It is about $1200 \mathrm{ml}$. As the residual air remains in the lungs, it has no effect on respiration efficiency.

Topic: Biology, Breathing and Exchange of Gases, NEET, NEET 2006
Which one of the following statements is incorrect about menstruation?

Options:
A The beginning of the cycle of menstruation is called menarche
B During normal menstruation about $40 \mathrm{ml}$ blood is lost
C The menstrual fluid can easily clot
D At menopause in the female, there is especially abrupt increase in gonadotropic hormones

The correct answer is:
The menstrual fluid can easily clot

Solution:
Menopause is a senile change in ovaries. After menopause the level of pituitary gonadotropins remain same or slightly increase. FSH is more than LH; but the ovaries are not responding to these hormone, because all the ovarian follicles are converted into follicular atresia. There is decline in the level of progesterone and estrogen. Initially the blood inside the uterus clots, but it is liquefied by the enzyme plasmin released by uterus. Menstrual fluid which is discharged cannot clot again.

Topic: Biology, Human Reproduction, NEET, NEET 2008 (Mains)
Which one of the following statements is incorrect, in case of homologous series of alkanes,

Options:
A The members of the series are isomers of each other
B The members of the series have similar chemical properties
C The members of the series have the general formula CnH2n+2 , where n is an integer
D The difference between any two successive members of the series corresponds to 14 unit of relative atomic mass

The correct answer is:
The members of the series are isomers of each other

Solution:
The difference between any two successive members of the homologous series -CH2- i.e., the molecular weight of every two adjacent members differ by 14.
(CH2=12+2=14)

Topic: Chemistry, Hydrocarbons, JEE Main
Which one of the following statements is not a tautology?

Options:
A pâ¨qâpâ¨(~q)
B p∧q→(~p∨q)
C pâpâ¨q
D pâ§qâp

The correct answer is:
p∨q→p∨(~q)

Solution:
Logical Statement p→q is false if and only if p is true and q is false.

So, when p is false, q is true, p∨q→p∨~q will be false.

Clearly p∨q→p∨~q is not a tautology.

Topic: Mathematics, Mathematical Reasoning, JEE Main, JEE Main 2019 (08 Apr Shift 2)
Which one of the following statements is not correct?

Options:
A The bond angle in methanol is 1 0 8 . 9 o
B Alcohols are weaker acids than water
C Carbon-oxygen bond length in methanol, CH3OH is shorter than that of C - O bond length in phenol.
D Acid strength of alcohols decreases in the following order RCH 2 OH > R 2 CHOH > R 3 COH â

The correct answer is:
Carbon-oxygen bond length in methanol, CH3OH is shorter than that of C - O bond length in phenol.

Solution:
Carbon-oxygen bond length in methanol, CH3OH is longer than that of C - O bond length in phenol. This is due to the partial double bond character in C-O bond of Phenol due to resonance.

Topic: Chemistry, Alcohols Phenols and Ethers, JEE Main
Which one of the following statements is not correct?

Options:
A
Alcohols are weaker acids than water

B
Acid strength of alcohols decreases in the following $\mathrm{RCH}_2 \mathrm{OH}>\mathrm{R}_2 \mathrm{CHOH}>\mathrm{R}_3 \mathrm{COH}$

C
Carbon-oxygen bond length in methanol, $\mathrm{CH}_3 \mathrm{OH}$ is shorter than that of $\mathrm{C}-\mathrm{O}$ bond length in phenol.

D

The correct answer is:
Carbon-oxygen bond length in methanol, $\mathrm{CH}_3 \mathrm{OH}$ is shorter than that of $\mathrm{C}-\mathrm{O}$ bond length in phenol.

Solution:
The $\mathrm{C}-\mathrm{O}$ bond length in alcohols is $142 \mathrm{pm}$ and in Phenol it is $136 \mathrm{pm}$. The $\mathrm{C}-\mathrm{O}$ bond length in phenol is shorter than that in methanol due to the conjugation of unshared pair of electrons on oxygen with the ring, which imparts double bond character to the $\mathrm{C}-\mathrm{O}$ bond.

Topic: Chemistry, Alcohols Phenols and Ethers, JEE Main, JEE Main 2014 (11 Apr Online)
Which one of the following statements is NOT correct?

Options:
A Eutrophication indicates that water body is polluted
B The dissolved oxygen concentration below 6 ppm inhibits fish growth
C Eutrophication leads to increase in the oxygen level in water
D Eutrophication leads to anaerobic conditions

The correct answer is:
Eutrophication leads to increase in the oxygen level in water

Solution:
Eutrophication leads to decrease in oxygen level of water.

Eutrophication is the process by which an entire body of water, or parts of it, becomes progressively enriched with minerals and nutrients, particularly nitrogen and phosphorus. It has also been defined as "nutrient-induced increase in phytoplankton productivity".

Topic: Chemistry, Environmental Chemistry, JEE Main, JEE Main 2021 (27 Jul Shift 1)
Which one of the following statements is not correct?

Options:
A $\mathrm{NO}_2$ is a lung irritant
B The municipal sewage has $B O D$ value of $100-4000$ ppm
C Main source of CO is automobile exhaust fumes
D COD is the measure of bacteria in water

The correct answer is:
COD is the measure of bacteria in water

Solution:
In environmental chemistry, chemical oxygen demand (COD) is the total amount of oxygen, (in ppm) that would be consumed by pollutants in a given water sample measured solution. Thus, COD is useful in terms of water quality.
Hence, option (d) is incorrect while the other given statements are correct. i.e.
- Municipal sewage has BOD (Biological oxygen demand) value of $100-4000 \mathrm{ppm}$.
- $\mathrm{NO}_2$ can causes irritation of eyes, noise even lungs. About $70 \%$ CO is mainly from automobiles exhaust fumes.

Topic: Chemistry, Environmental Chemistry, AP EAMCET, AP EAMCET 2019 (20 Apr Shift 2)
Which one of the following statements is not correct?

Options:
A Catalyst does not initiate any reaction.
B The value of equilibrium constant is changed in the presence of a catalyst in the reaction at equilibrium.
C Enzymes catalyse mainly bio-chemical reactions.
D Coenzymes increase the catalytic activity of enzyme.

The correct answer is:
The value of equilibrium constant is changed in the presence of a catalyst in the reaction at equilibrium.

Solution:
A catalyst decreases activation energies of both the forward and backward reaction by same amount, therefore, it speeds up both forward and backward reaction by same rate.
Equilibrium constant is therefore not affected by catalyst at a given temperature.

Topic: Chemistry, Chemical Equilibrium, NEET, NEET 2017