datavorous/entrance-exam-dataset huggingface dataset:
During the propagation of a nerve impulse, the action potential results from the movement of

Options:
A $\mathrm{K}^{+}$ions from extracellular fluid to intracellular fluid
B $\mathrm{Na}^{+}$ions from intracellular fluid to extracellular fluid
C $\mathrm{K}^{+}$ions from intracellular fluid to extracellular fluid
D $\mathrm{Na}^{+}$ions from extracellular fluid to intracellular fluid

The correct answer is:
$\mathrm{Na}^{+}$ions from extracellular fluid to intracellular fluid

Solution:
During the propagation of nerve impulse when a stimulus of adequate strength is applied to a polarised membrane, the permeability of the membrane to $\mathrm{Na}^{+}$is greatly increased at the point of stimulation. As a result the sodium ion channels permit the influx of $\mathrm{Na}^{+}$by diffusion. Since, there are more $\mathrm{Na}^{+}$ions entering than leaving, the electrical potential of the membrane changes from $-70 \mathrm{mV}$ towards zero. At $0 \mathrm{mV}$ the membrane is said to be depolarised. While the resting potential is determined largely by $\mathrm{K}^{+}$ions, the action potential is determined largely by $\mathrm{Na}^{+}$ions. Action potential is another name of nerve impulse. The stimulated negatively charged point on the outside of the membrane sends out an electrical current to the positive point adjacent to it. This local current causes the adjacent inner part of the membrane to reverse its potential from $-70 \mathrm{mV}$ to $+30 \mathrm{mV}$.

Topic: Biology, Neural Control and Coordination, NEET, NEET 2008 (Screening)
During the propagation of a nerve impulse, the action potential results from the movement of

Options:
A K+ ions from extracellular fluid to intracellular fluid
B Na+ ions from extracellular fluid to intracellular fluid
C K+ ions from intracellular fluid to extracellular fluid
D Na+ ions from intracellular fluid to extracellular fluid

The correct answer is:
Na+ ions from extracellular fluid to intracellular fluid

Solution:
The total sum of physio-electrochemical changes that takes place along the length of the nerve fibre is known as nerve impulse. Change in potential due to the stimulation of nerve fibre is called an action potential. During propagation of nerve impulse, Na+ enters inside so (+ve) charge is formed inside the membrane. K+ ions come out.

Topic: Biology, Neural Control and Coordination, NEET
During the purification process for recombinant DNA technology, addition of chilled ethanol precipitates out

Options:
A Polysaccharides
B RNA
C DNA
D HIstones

The correct answer is:
DNA

Solution:
Recombinant DNA technology involves several steps in specific sequence such as isolation of DNA, fragmentation of DNA by restriction endonucleases, isolation of a desired DNA fragment, ligation of the DNA fragment into a vector, transferring the recombinant DNA into the host, culturing the host cells in a medium at large scale and extraction of the desired product. Genes are located on long molecules of DNA interwined with proteins such as histones. The RNA can be removed by treatment with ribonuclease whereas proteins can be removed by treatment with protease. Other molecules can be removed by appropriate treatments and purified DNA ultimately precipitates out after the addition of chilled ethanol. This can be seen as collection of fine threads in the suspension.

Topic: Biology, Biotechnology - Principles and Processes, NEET, NEET 2023 (All India)
During the purification process for recombinant DNA technology, addition of chilled ethanol precipitates out:

Options:
A RNA
B DNA
C Histones
D Polysaccharides

The correct answer is:
DNA

Solution:
During the purification process for recombinant DNA technology, the RNA can be removed by treatment with ribonuclease whereas proteins can be removed by treatment with protease. Other molecules can be removed by appropriate treatments and purified DNA ultimately precipitates out after the addition of chilled ethanol.

Topic: Biology, Biotechnology - Principles and Processes, NEET, NEET 2021
During the reduction of nitro compounds with iron scrap and hydrochloric acid, what role does FeCl2 play?

Options:
A It acts as a reducing agent.
B It acts as a catalyst.
C It releases hydrochloric acid.
D It is a byproduct.

The correct answer is:
It is a byproduct.

Solution:
FeCl2 is a byproduct of the reaction.

Topic: Chemistry, Amines, NEET
During the synthesis phase, if the initial amount of DNA in the cell is 15 ng, then after the synthesis phase the amount of DNA in the cell will be ______.

Options:
A 15 ng
B 30 ng
C 45 ng
D 60 ng

The correct answer is:
30 ng

Solution:
During the S-phase of the cell cycle, DNA replication takes place and the quantity of DNA becomes double than the initial amount. If the initial amount of DNA is 15 ng then it increases to 30 ng during S-phase when DNA replication occurs.

Topic: Biology, Cell Cycle and Cell Division, NEET
During the translation process, the ATP molecule is required for

Options:
A Association of 50S subunit of the ribosome with the initiation complex.
B Binding of 30S subunit of the ribosome with mRNA
C Association of 30S-mRNA with formyl-met-tRNA.
D Charging of tRNA

The correct answer is:
Charging of tRNA

Solution:
In the first phase of translation, the amino acids are activated in the presence of ATP and linked to their cognate tRNA. This process is commonly called as charging of tRNA or aminoacylation of tRNA to be more specific.

Topic: Biology, Molecular Basis of Inheritance, NEET
During the transmission of nerve impulse through a nerve fibre, the inner membrane charge of the neurilemma will be

Options:
A First positive, then negative and continue to be positive
B First negative, then positive and continue to be positive
C First positive, then negative and again back to positive
D First negative, then positive and again back to negative.

The correct answer is:
First negative, then positive and again back to negative.

Solution:
The electrical potential difference across the plasma membrane is called the action potential or as a nerve impulse. At the resting stage, the outer membrane is positively charged and the inner membrane is negatively charged. Upon stimulus, the membrane becomes freely permeable to Na+. This leads to a rapid influx of Na+ followed by the reversal of the polarity at that site, i.e., the outer surface of the membrane becomes negatively charged and the inner side becomes positively charged. Later repolarization happens to get back the inner membrane to negatively charged.

Topic: Biology, Neural Control and Coordination, NEET
During the transmission of nerve impulse through a nerve fibre, the potential on the inner side of the plasma membrane has which type of electric change?

Options:
A first positive, then negative and continue to be negative
B first negative, then positive and continue to be positive
C first positive, then negative and again back to positive
D first negative, then positive and again back to negative.

The correct answer is:
first negative, then positive and again back to negative.

Solution:
The first channels to open are the sodium ion channels, which allow sodium ions to enter the cell. The resulting increase in positive charge inside the cell (up to about +40 $\mathrm{mV}$ ) starts the action potential. This is called the depolarization of the membrane. Potassium ion channels
Related Theory
Events that characterize the transmission of a nerve impulse. (Ref. to Fig. 25.7)

Topic: Biology, Neural Control and Coordination, NEET, NEET 2007
During the transport of water, the value of which of the following is always negative?

Options:
A water potential
B solute potential
C pressure potential
D Both (B) and (C)

The correct answer is:
solute potential

Solution:
The difference between the free energy of molecules of pure water and free energy of the solution is called the water potential of the system. Solute potential represents the concentration of the solutes. Water potential is negative in the presence of solutes. It is denoted by Ï s and is always negative. Pressure can build up in a plant system when water enters a plant cell due to diffusion causing a pressure built up against the cell wall, it makes the cell turgid (turgor pressure). This is called pressure potential. It is denoted by Ï p and is positive.

Topic: Biology, Transport in Plants, NEET
During the upward motion of the ball, what is the direction of acceleration when a player throws a ball upwards with an initial speed of 29.4 m/s?

Options:
A The acceleration is directed downward.
B The acceleration is directed upward.
C There is no acceleration during upward motion.
D The acceleration is directed horizontally.

The correct answer is:
The acceleration is directed downward.

Solution:
Correct Option is : (A)
The acceleration is directed downward.

Topic: Chemistry, Motion In One Dimension, NEET
During total solar eclipse, Fraunhoffer's lines appear bright because

Options:
A Moon totally covers both parts of sun photosphere and chromosphere.
B Sun light is scattered by moon.
C Moon blocks the radiations emitted by chromosphere.
D Moon blocks the radiations emitted by photosphere and radiations emitted by chromosphere reach the earth.

The correct answer is:
Moon blocks the radiations emitted by photosphere and radiations emitted by chromosphere reach the earth.

Solution:
During total solar eclipse Fraunhoffer's lines appear bright because Moon blocks the radiations emitted by photosphere and radiations emitted by chromosphere only reach the earth.

Topic: Physics, Thermal Properties of Matter, NEET
During transcription holoenzyme RNA polymerase binds to a DNA sequence and the DNA assumes a saddle like structure at that point. What is chat sequence called?

Options:
A AAAT box
B TATA box
C GGTT box
D CAAT box.

The correct answer is:
TATA box

Solution:
A TATA box is a DNA sequence that indicates where a genetic sequence can be read and decoded. Promoter region is the proximal area of transcription unit, which provides site for attachment of transcription factors ( $\sigma$ factor) and RNA polymerase. It is present upstream at 5 ' end of coding strand. It has special structure; an AT rich area called TATA box or Pribnow box. The TATA box is able to define the direction of transcription and also indicates the DNA strand to be read.
Related Theory
The TATA box is named for its conserved DNA sequence, which is most commonly TATAAA. Many eukaryotic genes have a conserved TATA box located 25-35 base pairs before the transcription start site of a gene.

Topic: Biology, Molecular Basis of Inheritance, NEET, NEET 2005
During transcription holoenzyme RNA polymerase binds to a DNA sequence and the DNA assumes a saddle-like structure at that point. This sequence is

Options:
A AAAT box
B TATA box
C GGTT box
D CAAT box

The correct answer is:
TATA box

Solution:
TATA box is present in the eukaryotic promoter region. It has a resemblance with the Pribnow box of prokaryotes. TATA box was identified by Dr. Hogness and so, it is also called a Hogness box. It is a 7 bp long region located 20 bp upstream to the start point. During the process of transcription the RNA polymerase (a holoenzyme which has a core unit and a Sigma factor for proper initiation of transcription) binds to the TATA box due to which DNA assumes a saddle-like structure at this place.

Topic: Biology, Molecular Basis of Inheritance, NEET
During transcription, if the nucleotide sequence of the DNA strand that is being coded is ATACG then the nucleotide sequence in the $m$ RNA would be:

Options:
A TATGC
B TCTGG
C UAUGC
D UATGC.

The correct answer is:
UAUGC

Solution:
Template strand only serves as the template for transcription whereas coding strand contains the exact same sequence of nucleotides in the mRNA except thymine.
Coding DNA strand 5'-ATACG-3'
Template DNA strand 3'-TATGC-5' mRNA synthesised 5'-UAUGC-3'
Caution
The direction of the template strand is in 3' to 5', whereas the coding strand shows opposite directional polarity, i.e., $5^{\prime}$ to $3^{\prime}$ direction.

Topic: Biology, Molecular Basis of Inheritance, NEET, NEET 2004
During transcription, if the nucleotide sequence of the DNA strand that is being coded is ATACG; then the nucleotide sequence in the mRNA would be

Options:
A UAUGC
B UATGC
C TATGC
D TCTGG

The correct answer is:
UAUGC

Solution:
Bases sequence in DNA will decide the base sequence in RNA. Uracil (U) will work as substitute for thymine (T) in mRNA. Complementary base pairing for mRNA will be
.

Topic: Biology, Molecular Basis of Inheritance, NEET
During transcription, RNA polymerase holoenzyme binds to a gene promoter and assumes a saddle - like structure. What is it's DNA-binding sequence?

Options:
A AATT
B $\mathrm{CACC}$
C TATA
D TTAA.

The correct answer is:
TATA

Solution:
The DNA binding sequence for RNA polymerase is called TATA box. The TATA box is present in the eukaryotic promoter region. It is a 7-bp long regionlocated 20 bp upstream to the start point. It is surrounded by GC rich sequences. During the process of transcription, the RNA polymerase (a holoenzyme which has a core unit and a sigma factor for properinitiation oftranscription) binds to the TATA box because of which DNA assumes a saddle-like structure at this place.
Related Theory
In molecular biology, the TATA box (also called the Goldberg-Hogness box) is a sequence of DNA found in the core promoter region of genes in archaea and eukaryotes. The bacterial homolog of the TATA box is called the Pribnow box which has a shorter consensus sequence.

Topic: Biology, Molecular Basis of Inheritance, NEET, NEET 2007
During transcription, the DNA site at which RNA polymerase binds is called:

Options:
A promoter
B regulator
C receptor
D enhancer

The correct answer is:
promoter

Solution:
Promoter region is the proximal area of transcription unit, which provides site for attachment of transcription factors ( $\sigma$ factor) and RNA polymerasc. It is present upstream at 5' end of coding strand. It has special structure; an AT rich area called TATA box or Pribnow box.

Topic: Biology, Molecular Basis of Inheritance, NEET, NEET 2003
During transcription, the DNA site at which RNA polymerase binds is called

Options:
A Terminator
B Promoter
C Regulator
D Operator

The correct answer is:
Promoter

Solution:
A regulator is a gene that forms a biochemical for suppressing the activity of the operator gene. The promoter is the gene that provides the point of attachment to RNA polymerase required for transcription of structural genes.

Topic: Biology, Molecular Basis of Inheritance, NEET
During transcription, which of the following base pairs form the complementary base pair?

Options:
A Adenine-Thymine
B Adenine-Uracil
C Thymine-Cytosine
D Guanine-Cytosine

The correct answer is:
Adenine-Uracil

Solution:
During transcription, the adenosine complements uracil instead of thymine.

Topic: Biology, Molecular Basis of Inheritance, NEET
During translation initiation in prokaryotes, a GTP molecule is needed in:

Options:
A formation of formyl-met- $t$ RNA
B binding of $30 \mathrm{~S}$ subunit of ribosome with $m$ RNA
C association of $30 \mathrm{~S} m \mathrm{RNA}$ with formyl-mel- $t$ RNA
D association of $50 \mathrm{~S}$ subunit of ribosome with initiation complex

The correct answer is:
association of $30 \mathrm{~S} m \mathrm{RNA}$ with formyl-mel- $t$ RNA

Solution:
Formyl-met-tRNA is formed by addition of methionine to tRNA fMet (formyl-methionine specifictRNA) by the fMet-tRNA synthetase to produce methioninetRNA and then transfer of formyl group from N10 formyl tetrahydrofolate to the amino group of the Met residue to produce $\mathrm{N}$-formyl methionine tRNA. Binding of $30 \mathrm{~S}$ ribosomal subunit to two initiation factors, IF-1 and IF-3 initiates translation. Factor IF-3 prevents the $30 \mathrm{~S}$ and $50 \mathrm{~S}$ subunits from combining prematurely and mediated binding of mRNA to $30 \mathrm{~S}$ subunit. This is followed by binding of complex consisting of the $30 \mathrm{~S}$ ribosomal subunit, IF-3, and mRNA with the initiating formyl met tRNA in presence of GTP-bound IF-2. The pairing of anticodon of tRNA with the mRNAs initiation codon induces binding of $50 \mathrm{~S}$ ribosomal subunit. Thus, association of $30 \mathrm{~S}$ mRNA with formyl-met-tRNA required GTP.

Topic: Biology, Molecular Basis of Inheritance, NEET, NEET 2003
During translation initiation in prokaryotes, a GTP molecule is needed in

Options:
A association of 50 S subunit of ribosome with initiation complex
B formation of formyl-met-RNA
C binding of 30 S subunit of ribosome with mRNA
D association of 30 S-mRNA with formylmet-tRNA

The correct answer is:
association of 30 S-mRNA with formylmet-tRNA

Solution:
For the formation of initiation complex during translation of mRNA, GTP is also required. The initiator AUG codes for the formyl methionine in prokaryotes.

Topic: Biology, Molecular Basis of Inheritance, NEET
During ventricular systole

Options:
A Oxygenated blood is pumped into the pulmonary artery and deoxygenated blood is pumped into the artery
B Oxygenated blood is pumped into the aorta and deoxygenated blood is pumped into the pulmonary vein
C Oxygenated blood is pumped into the pulmonary vein and deoxygenated blood is pumped into the pulmonary artery
D Oxygenated blood is pumped into the aorta and deoxygenated blood is pumped into the pulmonary artery

The correct answer is:
Oxygenated blood is pumped into the aorta and deoxygenated blood is pumped into the pulmonary artery

Solution:
When the contraction of ventricles occurs immediately after atrial systole, the pressure in the ventricles rises and closes the atrioventricular valves, preventing blood from returning to the atria. The pressure forces to open the semilunar valves of aorta and pulmonary artery to make entry of blood into these vessels, Oxygenated blood is pumped into the aorta and deoxygenated blood is pumped into the pulmonary artery.

Topic: Biology, Body Fluids and Circulation, NEET
During which phase of protein synthesis does the ribosome move from codon to codon along the mRNA?

Options:
A Initiation
B Elongation
C Termination
D Aminoacylation

The correct answer is:
Elongation

Solution:
During the elongation phase of protein synthesis, the ribosome moves from codon to codon along the mRNA.

Topic: Biology, Molecular Basis of Inheritance, NEET
During which phase of the cell cycle do centrioles duplicate in animal cells?

Options:
A G₁ phase
B S phase
C G₂ phase
D M phase

The correct answer is:
S phase

Solution:
In animal cells, during the S phase, DNA replication begins in the nucleus, and the centrioles duplicate in the cytoplasm.

Topic: Biology, Cell Cycle and Cell Division, NEET
During which phase of the cell cycle does the amount of DNA per cell double?

Options:
A G₂ phase
B S phase
C G₁ phase
D M phase

The correct answer is:
S phase

Solution:
S or synthesis phase marks the period during which DNA synthesis or replication takes place. During this time the amount of DNA per cell doubles.

Topic: Biology, Cell Cycle and Cell Division, NEET
During which phase of the cell cycle is the cell metabolically active and growing, but not replicating its DNA?

Options:
A G₂ phase
B S phase
C G₁ phase
D M phase

The correct answer is:
G₁ phase

Solution:
During G₁ phase the cell is metabolically active and continuously grows but does not replicate its DNA)

Topic: Biology, Cell Cycle and Cell Division, NEET
During which process are identical DNA strands transferred to daughter cells?

Options:
A Photosynthesis
B DNA replication
C Cellular respiration
D Protein synthesis

The correct answer is:
DNA replication

Solution:
DNA replication is the process in which identical DNA strands are produced and transferred to daughter cells during cell division.

Topic: Chemistry, Biomolecules, NEET
During which process does mRNA form a protein?

Options:
A Transcription
B Replication
C Translation
D Reverse transcription

The correct answer is:
Translation

Solution:
Translation is the process where the information carried by mRNA is used to synthesize a protein.

Topic: Chemistry, Biomolecules, NEET
During which stage in the complete oxidation of glucose arc the greatest number of ATP molecules formed from ADP?

Options:
A glycolysis
B Kreb's cycle
C conversion of pyruvic acid to acetyl CoA
D electron transport chain.

The correct answer is:
electron transport chain.

Solution:
The electron transport chain is primarily used to send protons across the membrane into the intermembrane space. This create a proton-motive force, which will drive ATP synthase in the final step of cellular respiration to create ATP from ADP and a phosphate group.
Related Theory
In chemiosmosis, the free energy from the series of redox reactions just described is used to pump hydrogen ions across the membrane. The uneven distribution of $\mathrm{H}^{+}$ions across the membrane establishes both concentration and electrical gradients, owing to the hydrogen ions' positive charge and their aggregation on one side of the membrane. If the membrane were open to diffusion by the hydrogen ions, the ions would tend to diffuse back across into the matrix, driven by their electrochemical gradient. Similarly, hydrogen ions in the matrix space can only pass through the inner mitochondrial membrane through an integral membrane protein called ATP synthase. This complex protein acts as a tiny generator, turned by the force of the hydrogen ions diffusing through it, down their electrochemical gradient. The turning of parts of this molecular machine facilitates the addition of a phosphate to ADP, forming ATP, using the potential energy of the hydrogen ion gradient.

Topic: Biology, Respiration in Plants, NEET, NEET 2005
During which stage in the complete oxidation of glucose is the greatest number of ATP molecules produced from ADP?

Options:
A Glycolysis
B Kreb's cycle
C Decarboxylation
D ETS

The correct answer is:
ETS

Solution:
Total NADH entering ETS is 10 (2 NADH from glycolysis, 2 NADH from link reaction, 6 NADH from Krebs' cycle. ATP formed from 1 NADH is 3. Thus ATP formed from 10 NADH is 30.
Total FADH2 entering ETS is 2 (from Krebs' cycle). ATP formed from 1 FADH2 is 2. Thus, ATP formed from 2 FADH2 is 4. Thus the ATP formed in ETS is 34 out of the total 38 produced by complete aerobic respiration of one molecule of glucose

Topic: Biology, Respiration in Plants, NEET
During which stage of meiosis I do the two chromosome pairs align independently of each other?

Options:
A Anaphase
B Metaphase
C Prophase
D Telophase

The correct answer is:
Metaphase

Solution:
During the metaphase of meiosis I, the two chromosome pairs align independently of each other at the metaphase plate.

Topic: Biology, Principles of Inheritance and Variation, NEET
During which stages of mitosis and meiosis, respectively does the centromere of each chromosome split?

Options:
A Telophase, Anaphase I
B Anaphase, Anaphase II
C Metaphase, Metaphase II
D Prophase, Telophase I

The correct answer is:
Anaphase, Anaphase II

Solution:
During anaphase of mitosis and anaphase II of meiosis centromere split and chromatids move towards opposite poles.

Topic: Biology, Cell Cycle and Cell Division, NEET, NEET 2023 (Manipur)
Dwarfism is a hormonal disorder caused due to:

Options:
A Deficiency of thyroxine secreted by the thyroid
B Excess of thyroxine
C Deficiency of STH produced by the pituitary
D Deficiency of FSH and LH

The correct answer is:
Deficiency of STH produced by the pituitary

Solution:
Growth hormone (GH) is released from anterior pituitary under the influence of hypothalamus releasing hormone GRH. This is also known as STH (Somatotrophic hormone). This hormone is responsible for growth of the body. Hypersecretion of this hormone results in acromegaly or gigantism. Hyposecretion causes dwarfism or acromicria.

Topic: Biology, Chemical Coordination and Integration, NEET