datavorous/entrance-exam-dataset huggingface dataset:
Assertion : In a regular medical examination of a small population, a 35 years old lady was found to have higher levels of oestrogens, progesterone in her blood.
Reason : The lady is 12 weeks pregnant.

Options:
A If both assertion and reason are true and reason is the correct explanation of assertion.
B If both assertion and reason are true but reason is not the correct explanation of assertion.
C If assertion is true but reason is false
D If both assertion and reason are false

The correct answer is:
If both assertion and reason are true and reason is the correct explanation of assertion.

Solution:
One of the hormones released by the placenta is human chorionic gonadotropin (hCG). This hormone is secreted by the trophoblast cells even before they become the chorion, and is the hormone assayed in the pregnancy test. Because its action is almost identical to that of luteinizing hormone (LH), hCG maintains the mother's corpus luteum. The corpus luteum, in turn, continues to secrete oestrogens and progesterone, thereby preventing menstruation and further ovulations. At around $10^{\text {th }}$ week, the secretion of human chorionic gonadotropin (hCG) by placenta declines, and the corpus luteum regresses as a result. However, menstruation does not occur because placenta itself secretes oestrogens and progesterone. In fact, the amounts of these two hormones secreted by the placenta far exceed the amounts that are ever secreted by the ovaries. The high levels of oestrogens and progesterone in the blood during pregnancy continue to inhibit the release of $\mathrm{FSH}$ and $\mathrm{LH}$, thereby preventing ovulation. They also help maintain the uterus and eventually prepare it for labor and delivery, and they stimulate the development of the mammary glands in the preparation forlactation after delivery.

Topic: Biology, Human Reproduction, AIIMS, AIIMS 2013
Assertion : In an adiabatic process, change in internal energy of a gas is equal to work done on or by the gas in the process.
Reason : Temperature of gas remains constant in an adiabatic process.

Options:
A If both assertion and reason are true and reason is the correct explanation of assertion.
B If both assertion and reason are true but reason is not the correct explanation of assertion.
C If assertion is true but reason is false.
D If both assertion and reason are false.

The correct answer is:
If assertion is true but reason is false.

Solution:
Assertion is true but reason is false.
In an adiabatic process, no exchange of heat is permissible i.e., $d Q=0$.
As, $d Q=d U+d W=0 . \quad \therefore d U=-d W$.

Topic: Physics, Thermodynamics, AIIMS, AIIMS 2016
Assertion : In an SHM, kinetic and potential energies become equal when the displacement is \(1 / \sqrt{2}\) times the amplitude.
Reason : In SHM, kinetic energy is zero when potential energy is maximum.

Options:
A If both assertion and reason are true and reason is the correct explanation of assertion
B If both assertion and reason are true but reason is not the correct explanation of assertion
C If assertion is true but reason is false
D If both assertion and reason are false.

The correct answer is:
If both assertion and reason are true but reason is not the correct explanation of assertion

Solution:
When the displacement of a particle executing SHM is $y$, then its $K . E .=\frac{1}{2} m \omega^2\left(a^2-y^2\right)$ and
$P . E .=\frac{1}{2} m \omega^2 y^2$
For $K . E .=P . E$. or $2 y^2=a^2$ or, $y=a / \sqrt{2}$. Since total energy remains constant through out the motion, which is $E=K . E .+P . E$. So, when P.E. is maximum then $K . E$. is zero and vice versa.

Topic: Physics, Oscillations, AIIMS, AIIMS 2008
Assertion : In angiosperms the conduction of water is more efficient because their xylem has vessels.
Reason : Conduction of water by vessel elements is an active process with energy supplied by xylem parenchyma rich in mitochondria.

Options:
A If both assertion and reason are true and reason is the correct explanation of the assertion
B If both assertion and reason are true but reason is not the correct explanation of the assertion
C If assertion is true, but reason is false
D Both assertion and reason are false statements.

The correct answer is:
If assertion is true, but reason is false

Solution:
Xylem is the main conducting tissue in plants. It consists of 4 different components - tracheids, trachea or vessels, xylem fibre and xylem parenchyma. Tracheids are elongated cells with tapering end. They are generally present in ferns and gymnosperms for conduction of water. In angiosperms, vessels are composite structure as these are formed by dissolution of end walls of row of cells i.e., vessels elements. So angiosperms, have more efficient system of conduction due to presence of vessels. Conduction of water by vessel elements is also known as ascent of sap. Water absorbed by roots, goes upward to replace the water loss by transpiration. The most accepted theory for ascent of sap is transpiration pull theory i.e., when water is lost by transpiration from the leaves, a tension is created in the xylem and due to this water absorbed by roots hair is passed through vessels to the leaves. The xylem parenchyma are mainly for storage function but sometimes help in conduction.

Topic: Biology, Anatomy of Flowering Plants, AIIMS, AIIMS 2006
Assertion : In angiosperms, transport of food and water is more efficient than gymnosperms and pteridophytes.
Reason : In angiosperms longitudinally arranged sieve elements and vessels with perforated end walls are present.

Options:
A If both assertion and reason are true and reason is the correct explanation of assertion
B If both assertion and reason are true but reason is not the correct explanation of assertion
C If assertion is true but reason is false
D If both assertion and reason are false.

The correct answer is:
If both assertion and reason are true and reason is the correct explanation of assertion

Solution:
Vessels are much elongated tubes which are closed at either end and are formed by the union of several short, wide and thickened cells called vessel elements. The end walls of vessel elements are transverse or oblique. They are often completely dissolved. The condition is called simple perforation plate. In a few cases the end walls remain intact and possess several pores in reticulate, scalariform or forminate forms. Such an end wall is called multiple perforation plate. Sieve tubes are elongated tubular conducting channels of phloem formed of several cells called sieve tube elements or members or sieve tube cells. Sieve tube members are placed end to end. The end walls are generally bulged out. They may be transverse or oblique. They have many small pores or sieve pits. Due to the presence of sieve pits the end walls are commonly called sieve plates. In some cases the end walls of sieve elements possess more than one porous area. Such an end wall is called compound sieve plate.
Gymnosperms \& pteridophytes lack these two vascular structures i.e. vessels and sieve elements. In angiosperms presence of vessels \& sieve elements in addition to all other vascular tissues make their food \& water transport more efficient.

Topic: Biology, Plant Kingdom, AIIMS, AIIMS 2011
Assertion: In case of motion of an ideal fluid in a horizontal tube, where the area of cross-section is minimum, pressure is maximum. Reason: Hydrostatic pressure in different ideal liquids at points of different depth can be same.

Options:
A If both Assertion and Reason are true and the Reason is correct explanation of the Assertion.
B If both Assertion and Reason are true but Reason is not explanation of the Assertion.
C If Assertion is true but the Reason is false.
D If Assertion is false but Reason is true.

The correct answer is:
If Assertion is false but Reason is true.

Solution:
According to the equation of continuity, speed of the fluid is maximum at the minimum cross-sectional area of a horizontal tube and so will be the kinetic energy. And according to Bernoulli's theorem, the pressure will be minimum, where kinetic energy is maximum. So Assertion is false.
The reason is true, as excess pressure due to fluid is ρgh. So, for fluids of different densities, pressure can be the same at different depths.

Topic: Physics, Mechanical Properties of Fluids, JEE Main
Assertion : In recombinant DNA technology, human genes are often transferred into bacteria (prokaryotes) or yeast (eukaryote).
Reason : Both bacteria and yeast multiply very fast to form huge populations which express the desired gene.

Options:
A If both assertion and reason are true and reason is the correct explanation of assertion
B If both assertion and reason are true but reason is not the correct explanation of assertion
C If assertion is true but reason is false
D If both assertion and reason are false.

The correct answer is:
If both assertion and reason are true and reason is the correct explanation of assertion

Solution:
In recombinant DNA technology widely used host for replication and amplification of recombinant DNA are prokaryotic $E$. coli and the eukaryotic yeast. They replicate very fast to form a large population which expresse desired gene. Yeast artificial chromosome (YAC) are important cloning tools for the analysis of complex genome such as that of humans. They allow the maintenance, propagation and analysis of such genome in an experimentally tractable system, the yeast.

Topic: Biology, Biotechnology - Principles and Processes, AIIMS, AIIMS 2005
Assertion : In recombinant DNA technology, human genes are often transferred into bacteria (prokaryotes) or yeasts (eukaryotes).
Reason : Both bacteria and yeasts multiply very fast to form huge populations which express the desired gene.

Options:
A If both assertion and reason are true and reason is the correct explanation of assertion.
B Ifboth assertion and reason are true but reason is not the correct explanation of assertion.
C If assertion is true but reason is false.
D If both assertion and reason are false.

The correct answer is:
If both assertion and reason are true and reason is the correct explanation of assertion.

Solution:
In recombinant DNA technology, widely used hosts for replication and amplification of recombinant DNA are prokaryotic E. coli and the eukaryotic yeast. They replicate very fast to form huge populations which express the desired gene. Yeast artificial chromosomes (YACs) are important cloning tools for the analysis of complex genome such as that of humans. They allow the maintenance, propagation and analysis of such genome in an experimentally tractable system, the yeast.

Topic: Biology, Biotechnology - Principles and Processes, AIIMS, AIIMS 2015
Assertion: In the reference frame of centre of mass, net force acting on system is always zero.
Reason: A pseudo force given by \( \vec{P}_{\mathrm{S}}=-m \vec{a}_{\mathrm{cm}} \) (where \( m \) is mass of system and \( \vec{a}_{\mathrm{cm}} \) is acceleration of centre of mass)
acts on system which balances all the external forces.

Options:
A If both Assertion and Reason are true and the Reason is correct explanation of the Assertion.
B If both Assertion and Reason are true, but Reason is not correct explanation of the Assertion.
C If Assertion is true, but the Reason is false.
D If Assertion is false, but Reason is true.

The correct answer is:
If both Assertion and Reason are true and the Reason is correct explanation of the Assertion.

Solution:
In centre of mass, frame acceleration of centre of mass is zero.

Hence, using Newton's second law of motion,

Fnet=macm=m×0=0

Also, Fnet=Fext+PS=0

and in ground frame, Fext=macm

From above two equations, we get,

PS=-Fext=-macm

Hence, both Assertion and Reason are true and the Reason is correct explanation of the Assertion.

Topic: Physics, Laws of Motion, JEE Main
Assertion : In woody stems, the amount of heart wood continues to increase year after year.
Reason : The cambial activity continues uninterrupted.

Options:
A If both assertion and reason are true and reason is the correct explanation of assertion
B If both assertion and reason are true but reason is not the correct explanation of assertion
C If assertion is true but reason is false
D If both assertion and reason are false.

The correct answer is:
If both assertion and reason are true and reason is the correct explanation of assertion

Solution:
Heartwood formation occurs spontaneously because it is a genetically programmed process. As a result of continued secondary growth for several years, the older parts of the stem and its old branches have a part of its secondary xylem rendered non - functional. Such a modified and non - functional secondary xylem is called the heart wood or duramen, the functional outer younger rings of secondary xylem constitute the sap wood or alburnum. With the passage of time and addition of new outer rings of secondary xylem due to cambial activity more rings of the sap wood are changed into heart wood. This leads to the increase in the thickness of heart wood, whereas the sap wood remains of about the same thickness.

Topic: Biology, Anatomy of Flowering Plants, AIIMS, AIIMS 2007
Assertion : Inbreeding increases homozygosity, thus exposes harmful recessive genes, which are eliminated by selection.Reason : Continued inbreeding reduces fertility and productivity.

Options:
A If both assertion and reason are true and reason is the correct explanation of assertion
B If both assertion and reason are true but reason is not the correct explanation of assertion
C If assertion is true but reason is false
D If both assertion and reason are false

The correct answer is:
If both assertion and reason are true but reason is not the correct explanation of assertion

Solution:
When the offsprings are produced by self fertilization or breeding between closely related parents it is called inbreeding. Inbreeding results in increase in homozygosity. The most revealing impact of inbreeding is the loss of vigour and physiological efficiency of the organisms characterized by reduction in size. A number of lethal and defective characters appear in the population which has undergone inbreeding (selfing). This loss of fitness in the progenies or decline in character expression with decreased heterozygosity arising from self mating is known as inbreeding depression or inbreeding decline. Continued inbreeding reduces fertility and even productivity. But the inbreeding progeny with lethal and harmful recessive genes being homozygous express these traits which otherwise remain hidden in heterozygous individuals. Natural selection works upon these individuals and eliminate them. Gradually, such genes get eliminated from the population.

Topic: Biology, Strategies for Enhancement in Food Production, AIIMS, AIIMS 2012
Assertion : Interferons are a type of antibodies produced by body cells infected by bacteria.
Reason : Interferons stimulate inflammation at the site of injury.

Options:
A If both assertion and reason are true and reason is the correct explanation of assertion
B If both assertion and reason are true but reason is not the correct explanation of assertion
C If assertion is true but reason is false
D If both assertion and reason are false.

The correct answer is:
If both assertion and reason are false.

Solution:
Interferons are not antibodies. These are natural proteins produced by the cells of the immune systems of most animals in response to challenges by foreign agents such as viruses, bacteria, parasites and tumor cells. Interferons belong to the large class of glycoproteins known as cytokines. In human body there are three types of interferon $-\alpha, \beta$ and $\gamma$.
Interferon alpha and beta are produced by many cell types, including T-cells and B-cells and are important component of the antiviral response. They stimulate both macrophages and NK (Natural Killer) cells. They both are also active against tumors. Inflammation is the first response to infection and injury and is critical to body defence. Basically, the inflammatory response is an attempt by the body to restore and maintain homeostasis after injury. Inflammation is the influx of fluid and cells that results in redness, swelling, heat, and pain at the infection site.

Topic: Biology, Human Health and Diseases, AIIMS, AIIMS 2005
Assertion : Long distance flow of photoassimilates in plants occurs through sieve tubes.
Reason : Mature sieve tubes have parietal cytoplasm and perforated sieve plates.

Options:
A If both Assertion and Reason are true and the reason is the correct explanation of the assertion
B If both Assertion and Reason are true but the reason is not the correct explanation of the assertion
C If Assertion is true statement but Reason is false
D if both Assertion and Reason are false statements

The correct answer is:
If both Assertion and Reason are true and the reason is the correct explanation of the assertion

Solution:
The main function of sieve tube is the transport of food products from green and storage organs of the plant to other organs of the plant. The sieve elements are sieve tubes arranged one above the other and have sieve plates (obligue or transverse perforated septa) on their end walls. The cytoplasm occur in the form of a thin living layer along the inner side of cellulose wall. The nucleus disappears in mature sieve elements.

Topic: Biology, Anatomy of Flowering Plants, AIIMS, AIIMS 2003
Assertion : Malpighian tubules are excretory organs in most of the insects.
Reason : These help in excretion of urea only.

Options:
A If both assertion and reason are true and reason is the correct explanation of assertion.
B If both assertion and reason are true but reason is not the correct explanation of assertion.
C If assertion is true but reason is false.
D If both assertion and reason are false.

The correct answer is:
If assertion is true but reason is false.

Solution:
Malpighian tubules are the excretory structures of most of the insects. They help in the removal of nitrogenous wastes mainly uric acid and osmoregulation.

Topic: Biology, Excretory Products and their Elimination, AIIMS, AIIMS 2019 (25 May)
Assertion
\(\mathrm{PbCl}_{2}\) is more stable than \(\mathrm{PbCl}_{4}\)
Reason
\(\mathrm{PbCl}_{4}\) is a powerful oxidising agent

Options:
A Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
B Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
C Assertion is correct but Reason is incorrect
D Assertion is incorrect but Reason is correct

The correct answer is:
Both Assertion and Reason are correct and Reason is the correct explanation for Assertion

Solution:
Pb4+ is less stable than Pb2+ due to the inert pair effect. So, Pb4+ compounds are very good oxidizing agents.

Pb4+ converts itself into Pb2+ to attain stability, the process is:

Pb4++2e- → Pb2+

Pb4+ is a very big cation and it's association with 4 anions like I- is not possible. Therefore, PbI4 does not exist and all other molecules exist.

Topic: Chemistry, Classification of Elements and Periodicity in Properties, JEE Main
Assertion : Meiosis II is similar to mitosis.
Reason : Meiosis I cannot occur in haploid cells.

Options:
A If both assertion and reason are true and reason is the correct explanation of assertion.
B If both assertion and reason are true but reason is not the correct explanation of assertion.
C If assertion is true but reason is false
D If both assertion and reason are false

The correct answer is:
If both assertion and reason are true but reason is not the correct explanation of assertion.

Solution:
Meiosis consists of two divisions, meiosis I and meiosis II. The first division of meiosis is called heterotypic or reduction division. During this division the number of chromosomes is reduced to half. The two chromatids of a chromosome become genetically different due to crossing over. These chromatids are separated in the second division of meiosis. The second meiotic division is known as homotypic or equational division, because the chromosome number remains the same as produced after the end of the first division. Though meiosis II is similar to mitosis, meiosis II is not mitosis because (i) it always occurs in haploid cells, (ii) it is not preceded by DNA replication, (iii) the two chromatids of a chromosome are often dissimilar, (iv) the daughter cells formed after meiosis II are neither similar to each other nor similar to the parent cell.

Topic: Biology, Cell Cycle and Cell Division, AIIMS, AIIMS 2013
Assertion : Movement of materials inside phloem is bidirectional i.e. it can be both upwards or downwards.
Reason : Movement of molecules inside xylem is unidirectional i.e. always upwards.

Options:
A If both assertion and reason are true and reason is the correct explanation of assertion
B If both assertion and reason are true but reason is not the correct explanation of assertion
C If assertion is true but reason is false
D If both assertion and reason are false.

The correct answer is:
If both assertion and reason are true but reason is not the correct explanation of assertion

Solution:
Long distance bulk movement of substances that occurs through conducting or vascular tissues of plants is called translocation. There are two vascular tissues, xylem and phloem. Xylem translocation is mainly from roots to aerial parts. It passes water with mineral salts, some organic nitrogen and hormones i.e. unidirectional. Phloem translocates organic substances and inorganic solutes first from leaves to all other parts of the plant and storage organs. Storage organs re-export organic nutrients to those parts which require the same as newly formed leaves and fruits i.e it is bidirectional.

Topic: Biology, Transport in Plants, AIIMS, AIIMS 2011
Assertion: Nitrogen and Oxygen are the main components in the atmosphere but these do not react to form oxides of nitrogen.

Reason: The reaction between nitrogen and oxygen requires high temperature.

Options:
A Both the Assertion and Reason are incorrect.
B Both Assertion and Reason are correct and the Reason is the correct explanation for the Assertion.
C Both Assertion and Reason are correct, but the Reason is not the correct explanation for the Assertion.
D The Assertion is incorrect but the Reason is correct.

The correct answer is:
Both Assertion and Reason are correct and the Reason is the correct explanation for the Assertion.

Solution:
N2(g) and O2(g) react under electric arc at 200C0 to form NO(g). Both the assertion and reason are correct and reason is correct explanation.

Topic: Chemistry, Environmental Chemistry, JEE Main, JEE Main 2015 (04 Apr)