datavorous/entrance-exam-dataset huggingface dataset:
Which of these modification of stem is incorrect?

Options:
A A lateral branch with short internodes and each node bearing a rosette of leaves and a tuft of roots is found in aquatic plants like Pistia and Eichhornia.
B In banana, pineapple and Chrysanthemum, the lateral branches originate from the basal and underground portion of the main stem, grow horizontally beneath the soil and then come out obliquely upward giving rise to leafy shoots.
C In plants like mint and jasmine a slender lateral branch arises from the base of the main axis and after growing aerially for some time arch downwards to touch the ground.
D Axillary buds of stems may also get modified into woody, straight and pointed thorns which are found in many plants such as cucumber and pumpkin

The correct answer is:
Axillary buds of stems may also get modified into woody, straight and pointed thorns which are found in many plants such as cucumber and pumpkin

Solution:
kins, watermelon) and grapevines. Axillary buds of stems may also get modified into woody, straight and pointed thorns. Thorns are found in many plants such as Citrus, Bougainvillea. They protect plants from browsing animals. Some plants of arid regions modify their stems into flattened (Opuntia), or fleshy cylindrical (Euphorbia) structures. They contain chlorophyll and carry out photosynthesis. Underground stems of some plants such as grass and strawberry, etc., spread to new niches and when older parts die new plants are formed. In plants like mint and jasmine a slender lateral branch arises from the base of the main axis and after growing aerially for some time arch downwards to touch the ground. A lateral branch with short internodes and each node bearing a rosette of leaves and a tuft of roots is found in aquatic plants like Pistia and Eichhornia. This is called offset. In banana, pineapple and Chrysanthemum, the lateral branches originate from the basal and underground portion of the main stem, grow horizontally beneath the soil and then come out obliquely upward giving rise to leafy shoots. These are called suckers.

Topic: Biology, Morphology of Flowering Plants, NEET
Which of these organisms show budding?

Options:
A Yeast
B Hydra
C Spongilla
D All of these

The correct answer is:
All of these

Solution:
In yeast, the division is unequal. Small buds are produced that remain attached initially to the parent cell which eventually get separated and mature into a new yeast organism.

Topic: Biology, Reproduction in Organisms, NEET
Which of these parts in the complex permanent tissue involved in transport of water is different from the rest?

Options:
A tracheid
B vessel
C xylem fibers
D xylem parenchyma

The correct answer is:
xylem parenchyma

Solution:
Xylem tissue is described as a complex and heterogeneous one. It is composed of four elements, two tracheary elements namely tracheids & vessels, these are dead cells whose function includes transportation of water & minerals. Remaining elements include xylem fibres & xylem parenchyma of which the only parenchyma is a living cell. To conclude, xylem parenchyma is the only living cell in the xylem tissue.

Topic: Biology, Anatomy of Flowering Plants, NEET
Which of these phases of the menstrual cycle is correctly matched with its period?

(I) Menstrual phase: 1st-4th Day
(II) Proliferative phase: 5th-13th Day
(III) Ovulatory phase: 14th Day
(IV) Luteal phase: 15th-28th Day

Options:
A I, II and III
B I, II and IV
C II and IV
D I, II, III and IV

The correct answer is:
I, II, III and IV

Solution:
The series of cyclic changes that take place in simultaneously in the ovaries and uterine wall (endometrium) of female reproductive tract stimulated by different concentrations of gonadotropins like FSH and LH is called menstrual cycle. It is mainly made up of 4 phases: Menstrual phase or Destructive phase - 1st-4th Day - endometrium degenerate. Proliferative phase or Follicular phase - 5 5th-13th Day - High F.S.H. level stimulates primordial follicle to mature into Graafian Follicle. Ovulatory phase - 14th Day - release of ovum. Luteal phase or Secretory phase - 15th-28th Day - rise in progesterone levels and the endometrium secretes nutrients for implantation

Topic: Biology, Human Reproduction, NEET
Which of these plants follow the CAM pathway for photosynthesis?

Options:
A Plants with no leaves
B Plants with their leaves reduced to thorns
C Plants with sunken stomata
D Plants with flattened stems

The correct answer is:
Plants with sunken stomata

Solution:
Many desert plants have a thick cuticle on their leaf surfaces and have their stomata arranged in deep pits (sunken) to minimise water loss through transpiration. They also have a special photosynthetic pathway (CAM) that enables their stomata to remain closed during day time. Some desert plants like Opuntia, have no leaves â they are reduced to spinesâ and the photosynthetic function is taken over by the flattened stems.

Topic: Biology, Organisms and Populations, NEET
Which of these plants have a modification of stem as indicated by the red arrow, in this diagram?

Options:
A Pistia and Eichhornia
B Pineapple and Chrysanthemum
C Mint and Jasmine
D Grass and Strawberry

The correct answer is:
Pineapple and Chrysanthemum

Solution:
The given diagram is of suckers a type of underground stem. In this modification, the lateral branches originate from the basal and underground portion of the main stem, grow horizontally beneath the soil and then come out obliquely upward giving rise to leafy shoots. It is seen in banana, pineapple and Chrysanthemum. Underground stems of some plants such as grass and strawberry, etc., spread to new niches and when older parts die new plants are formed. In plants like mint and jasmine a slender lateral branch arises from the base of the main axis and after growing aerially for some time arch downwards to touch the ground. A lateral branch with short internodes and each node bearing a rosette of leaves and a tuft of roots is found in aquatic plants like Pistia and Eichhornia.

Topic: Biology, Morphology of Flowering Plants, NEET
Which of these species will have non-zero magnetic moment?

Options:
A $\mathrm{Na}^{+}$
B Mg
C $F^{-}$
D $A r^{+}$

The correct answer is:
$A r^{+}$

Solution:
Key point The species which has one or more unpaired electrons have non-zero magnetic moment.
Electronic configuration of
$$
\begin{array}{l}
\mathrm{Na}^{+}(Z=11)=1 \mathrm{s}^{2} 2 \mathrm{s}^{2} 2 p^{6} \\
\mathrm{Mg}(Z=12)=1 \mathrm{s}^{2} 2 \mathrm{s}^{2} 2 p^{6} 3 \mathrm{s}^{2} \\
\mathrm{F}^{-}(Z=9)=1 \mathrm{s}^{2} 2 s^{2} 2 p^{6} \\
\quad \mathrm{Ar}^{+}(Z=18)=1 \mathrm{s}^{2} 2 \mathrm{s}^{2} 2 p^{6} 3 \mathrm{s}^{2} 3 p^{5}
\end{array}
$$
As, Ar $^{+}$ has an unpaired electron, it has non-zero magnetic moment. Hence, (d) is the correct option.

Topic: Chemistry, Structure of Atom, JEE Main
Which of these statements about proximal convoluted tubule is/are true?

I. It is lined by simple columnar brush border epithelium which increases the surface area for reabsorption.

II. Nearly all of the essential nutrients and 70%–80% of electrolytes and water are reabsorbed by this segment.

III. It selectively secretes hydrogen ions, ammonia and potassium ions into the filtrate.

IV. It is the most convoluted part of the nephron and is present in the medullary region of the kidney.

Options:
A I and IV
B I, II and III
C II and III
D I, II, III and IV

The correct answer is:
II and III

Solution:
Proximal convoluted tubule or PCT is the most convoluted part of the nephron located in the renal cortex. It is the first part of the renal tube and is internally lined by simple cuboidal brush border epithelium, which increases the surface area for reabsorption. There is maximum reabsorption of nutrients, electrolytes and water in this region of the nephron. It also maintains the pH by tubular secretion of hydrogen ions, ammonia and potassium ions.

Topic: Biology, Excretory Products and their Elimination, NEET
Which of these statements about the adrenal cortex is true?

Options:
A It secretes some androgens
B The zonaglomerulosa secretes aldosterone.
C The zonafasciculata is stimulated by ACTH.
D All of the above

The correct answer is:
All of the above

Solution:
Adrenal gland is divided into outer cortex and inner medulla. The cortex is further divided into three zones depending on the shape of cells. The outer zone glomerulosa that consists of glomerular shaped cells and secrete mineralocorticoids. The main mineralocorticoid is Aldosterone. The middle layer is known as Zona Fasciculata that consists of fibres and it is the zone with maximum thickness and it secretes Glucocorticoids. The inner zone is Zona reticularis and it secretes Sex hormones. Adrenal cortex is under the control of ACTH. This is Adrenocorticotrophin hormone and is released by anterior pituitary under the influence of Hypothalamus.

Topic: Biology, Chemical Coordination and Integration, NEET
Which of these statements about the counter current mechanism is true?

Options:
A NaCl is transported by the ascending limb of Henle's loop which is exchanged with the descending limb of vasa recta. NaCl is returned to the interstitium by the ascending portion of vasa recta.
B NaCl is transported by the descending limb of Henle's loop which is exchanged with the ascending limb of vasa recta. NaCl is returned to the interstitium by the descending portion of vasa recta.
C NaCl is transported by the ascending limb of Henle's loop which is exchanged with the ascending limb of vasa recta. NaCl is returned to the interstitium by the ascending portion of vasa recta.
D NaCl is transported by the descending limb of Henle's loop which is exchanged with the descending limb of vasa recta. NaCl is returned to the interstitium by the descending portion of vasa recta.

The correct answer is:
NaCl is transported by the ascending limb of Henle's loop which is exchanged with the descending limb of vasa recta. NaCl is returned to the interstitium by the ascending portion of vasa recta.

Solution:
The Henle's loop and vasa recta play a significant role in producing concentrated urine in mammals. The flow of filtrate in the two limbs of Henle's loop is in opposite directions and thus forms a counter current. The flow of blood through the two limbs of vasa recta is also in a counter current pattern. The proximity between the Henle's loop and vasa recta, as well as the counter current in them help in maintaining an increasing osmolarity towards the inner medullary interstitium, i.e., from 300 mOsmol/L in the cortex to about 1200 mOsmol/L in the inner medulla. This gradient is mainly caused by NaCl and urea. NaCl is transported by the ascending limb of Henle's loop which is exchanged with the descending limb of vasa recta. NaCl is returned to the interstitium by the ascending portion of vasa recta. Similarly, small amounts of urea enter the thin segment of the ascending limb of Henle's loop which is transported back to the interstitium by the collecting tubule.

Topic: Biology, Excretory Products and their Elimination, NEET
Which of these statements about the human ear is true?

Options:
A The crista and macula are the specific receptors of the vestibular apparatus responsible for maintenance of balance of the body and posture.
B The fluid between bony labyrinth and membranous labyrinth is endolymph
C The lateral most ear ossicle is stapes while the medial most ear ossicle is malleus
D A large number of processes called stereo cilia are projected from the basal part of each hair cell of organ of Corti.

The correct answer is:
The crista and macula are the specific receptors of the vestibular apparatus responsible for maintenance of balance of the body and posture.

Solution:
The fluid between bony labyrinth and membranous labyrinth is perilymph while the fluid within membranous labyrinth is endolymph. The lateral most ear ossicle is malleus which is attached to the tympanic membrane while the medial most ear ossicle is stapes which is attached to oval window of vestibule. A large number of processes called stereo cilia are projected from the apical part of each hair cell of organ of Corti. The basal end of the hair cell is in close contact with the afferent nerve fibres.

Topic: Biology, Neural Control and Coordination, NEET
Which of these statements about transport in plant is incorrect?

Options:
A The direction of movement in the phloem can be upwards or downwards, i.e., bi-directional.
B Phloem sap is mainly water and sucrose, but other sugars, hormones and amino acids are also transported or translocated through phloem.
C Xylem transports only inorganic nutrients while phloem transports only organic materials
D The chief sinks for the mineral elements are the growing regions of the plant, such as the apical and lateral meristems, young leaves, developing flowers, fruits and seeds, and the storage organs

The correct answer is:
Xylem transports only inorganic nutrients while phloem transports only organic materials

Solution:
Phloem sap is mainly water and sucrose, but other sugars, hormones, and amino acids are also transported or translocated through the phloem. Food, primarily sucrose, is transported by the vascular tissue phloem from a source to a sink. Usually, the source is understood to be that part of the plant which synthesizes the food, i.e., the leaf, and sink, the part that needs or stores the food. But, the source and sink may be reversed depending on the season, or the plant's needs. Sugar stored in roots may be mobilized to become a source of food in the early spring when the buds of trees, act as a sink; they need energy for growth and development of the photosynthetic apparatus. Since the source-sink relationship is variable, the direction of movement in the phloem can be upwards or downwards, i.e., bi-directional. An analysis of the xylem exudates shows that though some of the nitrogen travels as inorganic ions, much of it is carried in the organic form as amino acids and related compounds. Similarly, small amounts of P and S are carried as organic compounds. In addition, a small amount of exchange of materials does take place between xylem and phloem. Hence, it is not that we can clearly make a distinction and say categorically that xylem transports only inorganic nutrients while phloem transports only organic materials

Topic: Biology, Transport in Plants, NEET
Which of these statements is not true ?

Options:
A LiAlH4 is versatile reducing agent in organic synthesis.
B NO+ is isoelectronic with O2
C Boron is always covalent in its compounds
D In aqueous solution, the Tl+ ion is much more stable than Tl (III)

The correct answer is:
NO+ is isoelectronic with O2

Solution:
(i) LiAlH4 is a versatile reducing agent
(ii) NO+ (14 electrons), O2(16 electrons) not isoelectronic
(iii) âTl+ is more stable due to Inert pair effect
(iv) Boron compounds are ionic as well
B 2 O 3 + 2 NaOH → 2 NaBO 2 + H 2 O
(Sodium meta Borate)

Topic: Chemistry, p Block Elements (Group 13 & 14), JEE Main, JEE Main 2014 (19 Apr Online)
Which of these statements is not true ?

Options:
A LiAlH4 is versatile reducing agent in organic synthesis.
B NO+ is isoelectronic with O2
C Boron is always covalent in its compounds
D In aqueous solution, the Tl+ ion is much more stable than Tl (III)

The correct answer is:
NO+ is isoelectronic with O2

Solution:
(i) LiAlH4 is a versatile reducing agent
(ii) NO+ (14 electrons), O2(16 electrons) not isoelectronic
(iii) âTl+ is more stable due to Inert pair effect
(iv) Boron compounds are ionic as well
B 2 O 3 + 2 NaOH → 2 NaBO 2 + H 2 O
(Sodium meta Borate)

Topic: Chemistry, p Block Elements (Group 13 & 14), JEE Main
Which of these will not react with acetylene ?

Options:
A
$\mathrm{NaOH}$

B
ammonical $\mathrm{AgNO}_3$

C
$\mathrm{Na}$

D
$\mathrm{HCl}$

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

Solution:

Topic: Chemistry, General Organic Chemistry, JEE Main, JEE Main 2002
Which of these will produce the highest yield Friedel Crafts reaction?

Options:
A
B
C
D

The correct answer is:

Solution:
Aniline forms anilinium complex with Lewis acid, so phenol is most reactive among the given compounds for electrophilic substitution reaction.

Topic: Chemistry, Haloalkanes and Haloarenes, JEE Main, JEE Main 2020 (09 Jan Shift 1)
Which of two water sample A & B with BOD of 10 and 20 respectively, then mark correct option

Options:
A A is more polluted
B B is more polluted
C A and B both are equally polluted
D A and B both are equally suitable for drinking.

The correct answer is:
B is more polluted

Solution:
BOD for a clean water should be less than 5; where as highly polluted water could have a BOD value of 17 ppm or more.
So, B is more polluted and not suitable for drinking

Topic: Chemistry, Environmental Chemistry, JEE Main
Which one among the following chemical tests is used to distinguish monosaccharide from disaccharide ?

Options:
A Seliwanoff's test
B Iodine test
C Barfoed test
D Tollen's test

The correct answer is:
Barfoed test

Solution:
Barford test is used for distinguish monosaccharide from disaccharide

Topic: Chemistry, Biomolecules, JEE Main, JEE Main 2021 (27 Jul Shift 1)
Which one among the following complex ions has the highest paramagnetism?

Options:
A Cr(H2O)63+
B Fe(H2O)62+
C CuH2O62+
D ZnH2O62+

The correct answer is:
Fe(H2O)62+

Solution:
μ=n(n+2) BM , n is number of unpaired electrons.
[Fe(H2O)6]2+ has four unpaired electrons, [Cr(H2O)6]3+,[Cu(H2O)6]2+ and [Zn(H2O)6]2+ have 3, 1, 0 unpaired electrons respectively.

Topic: Chemistry, Coordination Compounds, JEE Main
Which one among the following does not have the hydrogen bond

Options:
A Phenol
B Liquid $N H_3$
C Water
D Liquid $\mathrm{HCl}$

The correct answer is:
Liquid $\mathrm{HCl}$

Solution:
The correct option is D Hydrochloric acid
$\mathrm{HCl}$ does not form hydrogen bond. For the formation of hydrogen bond, at least one hydrogen atom must be bonded to one of the three most electonegative atoms, i.e, $\mathrm{O}, \mathrm{N}$ and $\mathrm{F}$.

Topic: Chemistry, Chemical Bonding and Molecular Structure, JEE Main
Which one among the following does not have the hydrogen bond?

Options:
A Phenol
B Water
C Liquid \( \mathrm{NH}_{3} \)
D Liquid \( \mathrm{HCl} \)

The correct answer is:
Liquid \( \mathrm{HCl} \)

Solution:
A hydrogen bond is formed between H and a more electronegative atom like F,O or N . It is a form of dipole-dipole attraction between molecules.

In liquid HCl, a hydrogen bond cannot be formed with Cl atom due to its greater size and lesser electronegativity as compared to F,O or N.

Topic: Chemistry, Chemical Bonding and Molecular Structure, JEE Main
Which one among the following ions, is smallest in size

Options:
A N3-
B O2-
C F-
D Na+

The correct answer is:
Na+

Solution:
Na+<F-<O2-<N3- , All are isoelectronic species, hence effective number charge is highest for Na+ so it has smallest size.

Topic: Chemistry, Classification of Elements and Periodicity in Properties, JEE Main
Which one among the following is the best reagent for the conversion of pent-3-en-2-ol into pent-3-en-2-one?

Options:
A KMnO4/H2SO4
B K2Cr2O7/H2SO4
C CrO3/CH3COOH
D

The correct answer is:

Solution:
P.C.C. is selective oxidising agent which does not affect the oxidation of alkene.

Topic: Chemistry, Alcohols Phenols and Ethers, JEE Main
Which one among the following metals is the weakest reducing agent?

Options:
A K
B Rb
C Na
D Li

The correct answer is:
Na

Solution:
According to the electrochemical series

K+ / K → -2.93V

Rb+ / Rb → -2.98V

Na+ / Na → -2.71V

Li+ / Li → -3.05V

Among the given alkali metals, sodium metal is the weakest reducing agent as its standard reduction potential is least negative which is ENa+/Na° = -2.71

So, the correct option is C.

Topic: Chemistry, s Block Elements, JEE Main, JEE Main 2023 (25 Jan Shift 2)
Which one among the following pairs of ions cannot be separated by $H_2 S$ in dilute hydrochloric acid

Options:
A $\mathrm{Bi}^{3+}, \mathrm{Sn}^{4+}$
B $\mathrm{Al}^{3+}, \mathrm{Hg}^{2+}$
C $\mathrm{Zn}^{2+}, \mathrm{Cu}^{2+}$
D $\mathrm{Ni}^{2+}, \mathrm{Cu}^{2+}$

The correct answer is:
$\mathrm{Bi}^{3+}, \mathrm{Sn}^{4+}$

Solution:
Both will precipitate as sulphide

Topic: Chemistry, Practical Chemistry, JEE Main
Which one amongst the following are good oxidising agents?

(a) Sm2+

(b) Ce2+

(c) Ce4+

(d) Tb4+

Choose the most appropriate answer from the options given below :

Options:
A C only
B D only
C A and B only
D C and D only

The correct answer is:
C and D only

Solution:
The common oxidation state of lanthanide is +3. The lanthanide ions having +2 oxidation state undergo oxidation readily, hence they act as reducing agents. The lanthanide ions having +4 oxidation state undergo reduction readily, hence they act as oxidising agents.

Hence, Ce+4 and Tb+4 act as oxidising agent

Topic: Chemistry, d and f Block Elements, JEE Main, JEE Main 2023 (24 Jan Shift 2)
Which one does not give cannizzaro's reaction

Options:
A Which one does not give cannizzaro's reaction
B Benzaldehyde
C p-methoxy benzaldehyde
D 2,2 dimethyl propanal

The correct answer is:
2,2 dimethyl propanal

Solution:
Aldehyde, which does not have the $\alpha-H$ atom, gives cannizzaro's reaction on heating with conc. alkali solution $(50 \%)$

Topic: Chemistry, Aldehydes and Ketones, JEE Main
Which one has the highest boiling point

Options:
A Acetone
B Ethyl alcohol
C Diethyl ether
D Chloroform

The correct answer is:
Ethyl alcohol

Solution:
Ethyl alcohol has a intermolecular hydrogen bond.

Topic: Chemistry, Chemical Bonding and Molecular Structure, JEE Main
Which one has the highest boiling point?

Options:
A Xe
B He
C Ne
D Kr

The correct answer is:
Xe

Solution:
In case of noble gases, Vander waal forces exist between atoms which are directly proportional to size of elements.

Due to bigger size of Xe, it's electron cloud gets polarized more and as a result it has stronger Van Der Waals forces leading to a higher boiling point.

Topic: Chemistry, p Block Elements (Group 15, 16, 17 & 18), JEE Main, JEE Main 2015 (04 Apr)
Which one in the following is not the resonance structure of $\mathrm{CO}_2$

Options:
A $O=C=O$
B $-\mathrm{O}-\mathrm{C} \equiv \mathrm{O}^{+}$
C ${ }^{+} \mathrm{O} \equiv \mathrm{C}-\mathrm{O}^{-}$
D $O \equiv C=O$

The correct answer is:
$O \equiv C=O$

Solution:
Choice (1), (2), (3) are the resonance structures of $\mathrm{CO}_2$

Topic: Chemistry, Chemical Bonding and Molecular Structure, JEE Main
Which one is a colligative property?

Options:
A Boiling point
B Vapour pressure
C Osmotic pressure
D Freezing point

The correct answer is:
Osmotic pressure

Solution:
Osmotic pressure is a colligative property because it depends upon the number of solute particles but not on the nature of the solute.

Topic: Chemistry, Solutions, JEE Main
Which one is a true statement regarding DNA polymerase used in PCR?

Options:
A It is used to ligate introduced DNA in recipient cells
B It serves as a selectable marker
C It is isolated from a virus
D It remains active at high temperature

The correct answer is:
It remains active at high temperature

Solution:
Polymerase Chain Reaction (PCR) is used to amplify a DNA segment or to synthesize in vitro the multiple copies of gene (or DNA) of interest, using two sets of primers and the enzyme DNA polymerase. This enzyme is isolated from a bacterium Thermus aquaticus and it remains active during the high temperature but high temperature induced denaturation of double stranded DNA.

Topic: Biology, Biotechnology - Principles and Processes, NEET, NEET 2012 (Screening)
Which one is a true statement regarding DNA polymerase used in PCR?

Options:
A It is used to ligate introduced DNA in recipient cell
B It serves as a selectable marker
C It is isolated from a virus
D It remains active at high temperature

The correct answer is:
It remains active at high temperature

Solution:
The name of the DNA polymerase used in PCR is Taq polymerase extracted from a thermophilic bacteria Thermus aquaticus. The enzyme resists high temperature and performs polymerization of nucleotides.

Topic: Biology, Biotechnology - Principles and Processes, NEET