datavorous/entrance-exam-dataset huggingface dataset:
During meiosis I, the chromosomes start pairing at:

Options:
A Zygotene
B Pachytene
C Diplotene
D Leptotene

The correct answer is:
Zygotene

Solution:
During meiosis pairing of chromosome starts at zygotene, this process of pairing is called synapsis or syndesis in which homologous chromosomes comes close together and forms pair known as bivalent. A proteinaceous network develops between two chromosomes of a pair known as synaptonemal chromosome.

Topic: Biology, Cell Cycle and Cell Division, NEET
During menstrual cycle, which hormone shows dual peak?

Options:
A Estrogen - Both peaks during first half of menstrual cycle.
B Estrogen - One peak during first half and second peak during second half of menstrual cycle.
C Progesterone - Both peaks during first half of menstrual cycle.
D Progesterone - One peak during first half and second peak during second half of menstrual cycle

The correct answer is:
Estrogen - One peak during first half and second peak during second half of menstrual cycle.

Solution:

Topic: Biology, Human Reproduction, NEET
During metaphase, what happens to the chromosomes?

Options:
A They are held together by the centromere
B They are moved into position at the center of the cell
C They are condensed and easily studied under the microscope
D All of the above

The correct answer is:
All of the above

Solution:
During metaphase, the chromosomes are held together by the centromere, moved into position at the center of the cell, and condensed and easily studied under the microscope.

Topic: Biology, Cell Cycle and Cell Division, NEET
During micelle formation

Options:
A ΔH=+ve,ΔS=+ve
B ΔH=-ve,ΔS=-ve
C ΔH=-ve,ΔS=+ve
D ΔH=+ve,ΔS=-ve

The correct answer is:
ΔH=+ve,ΔS=-ve

Solution:
During micelle formation ΔH=+ve,ΔS=-ve

Topic: Chemistry, Surface Chemistry, NEET
During mitosis ER and nucleolus begin to disappear at

Options:
A late prophase
B early metaphase
C late metaphase
D early prophase

The correct answer is:
early prophase

Solution:
In mitosis, prophase is the longest phase of karyokinesis. In early prophase, nuclear membranes, nucleolus start disintegrating. Cells cytoskeleton, Golgi complex, ER, etc disappear.

Topic: Biology, Cell Cycle and Cell Division, NEET, NEET 2010 (Screening)
During muscle contraction, hydrolysis of ATP results in a change in the:

Options:
A structure of the myofibrils
B conformation of myosin
C conformation of actin
D structure of the sarcoplasmic reticulum

The correct answer is:
conformation of myosin

Solution:
The binding of ATP to myosin induces the conformational changes in such a manner the dissociation of actin from the myosin will occur. This ATP hydrolysis changes the orientation of the myosin relative to the actin filament and moves to the next actin subunit.

Topic: Biology, Locomotion and Movement, NEET
During muscle contraction, what could be the correct sequence?

A. Release of calcium ions into the sarcoplasm.
B. Release of Acetylcholine.
C. Sliding of actin filaments over each other.
D. Break down of ATP to form a cross bridge.

Options:
A A D B C
B A B D C
C B A C D
D B A D C

The correct answer is:
B A D C

Solution:
Steps involved in muscle contraction are the following:
A. The central nervous system (CNS) sends a signal via a motor neuron of a motor unit.
B. The signal reaches the neuromuscular junction → Release of neurotransmitter (Acetylcholine) → Generation of the action potential in the sarcolemma.
C. Spread of Action potential through the muscle fibre and causes the release of Ca ions into the sarcoplasm.
D. An increase in Ca+2 level within sarcoplasm → Calcium binds with a subunit of troponin on actin filaments → Active sites for myosin are exposed.
E. Binding of the myosin head to the exposed active sites on actin to form a cross bridge. This step utilizes the energy from ATP hydrolysis. Attached actin filaments are pulled towards the center of the 'A' band. The 'Z' line attached to these actins is also pulled inwards resulting in a shortening of the sarcomere (or contraction).
F. The myosin enters the relaxed state releasing the ADP and Pi. New ATP binds resulting in the breaking of the cross-bridge. Hydrolysis of ATP by the myosin head again results in the cross-bridge formation.
G. Repeated formation and breaking of cross-bridges result in further sliding of filaments over each other. Thus contraction occurs.

Topic: Biology, Locomotion and Movement, NEET
During N2 fixation in root nodule to form NH3 molecule. How many ATP are consumed?

Options:
A 16
B 4
C 2
D 8

The correct answer is:
8

Solution:
When nitrogen fixation in plants is done with the help of bacteria then it is called biological nitrogen fixation. It can be represented by the following equation in which one molecule of nitrogen produces two molecules of ammonia at the expense of 16 ATP.
N2+8H+8e+16 ATPâ2 Ammonia+H2+16ADP+16Pi
So, only 8 ATP molecules are consumed to form one molecule of ammonia.

Topic: Biology, Mineral Nutrition, NEET
During non-cyclic photophosphorylation, ATP molecules are produced through electron flow

Options:
A from H2O to PS II.
B from PS II to PS I.
C from PS I to NADP.
D from PS I to ferredoxin.

The correct answer is:
from PS II to PS I.

Solution:
Phosphorylation is a process wherein the ATP is synthesized from ADP and inorganic phosphate in the presence of light. The photosystem PS I and PS II work in series, where first comes PS II then PS I such a process is called as non-cyclic photophosphorylation. These photosystems are connected through the electron transport chain and the phosphorylation occurs due to the cyclic flow of electrons from PS II to PS I in the lamellae.

Topic: Biology, Photosynthesis in Higher Plants, NEET
During non-cyclic photophosphorylation, when electrons are lost from the reaction centre at PSII, what is the source which replaces these electrons?

Options:
A Oxygen
B Water
C Carbon dioxide
D Light

The correct answer is:
Water

Solution:
Photolysis of water: It is a light-mediated oxidation process associated with PSII characterized by the splitting of a water molecules into electrons, hydrogen ions and oxygen. The electrons released during photolysis are accepted by P680 of PSII, which has lost its electron due to excitation. The H+ ions released are used to reduce NADP toNADPH+H+ that enters the dark reaction of photosynthesis. The reaction is as follows:

2H2O→Mn+2, Ca+2, Cl-Sunlinght O2+4H++4e-

Topic: Biology, Photosynthesis in Higher Plants, NEET, NEET 2020 (Phase 2)
During normal inspiration

Options:
A Contraction of diaphragm occurs which increases the volume of thoracic chamber in the antero-posterior axis.
B Contraction of diaphragm occurs which increases the volume of thoracic chamber in the dorso-ventral axis.
C Contraction of external intercostal muscle occurs which increases the volume of thoracic chamber in the antero-posterior axis.
D Contraction of internal intercostals muscle occurs which increases the volume of thoracic chamberin the dorso-ventral axis.

The correct answer is:
Contraction of diaphragm occurs which increases the volume of thoracic chamber in the antero-posterior axis.

Solution:
Mechanism of Normal inspiration:
A. Contraction of diaphragm â Volume of the thoracic chamber in the anteroposterior axis increases.
B. The contraction of external intercostal muscles â Ribs and the sternum are lifted up â An increase in the volume of the thoracic chamber in the dorso-ventral axis.
C. Increase in the thoracic volume â Increase in pulmonary volume â Decrease in the intra-pulmonary pressure.
D. Intra-pulmonary pressure becomes less than the atmospheric pressure. This forces the air from outside to move into the lungs (inspiration).

Topic: Biology, Breathing and Exchange of Gases, NEET
During old age, the immunity of a person begins to decrease and as a result, they become more susceptible to infections and diseases. What could be the probable reason for this?

Options:
A Degeneration of thyroid gland
B Degeneration of pineal gland
C Degeneration of thymus gland
D Degeneration of pituitary gland

The correct answer is:
Degeneration of thymus gland

Solution:
The thymus gland is responsible for the secretion of thymosins which play a major role in the differentiation of T-lymphocytes and provide cellular immunity. They also promote antibody production and provide humoral immunity. Hence, degeneration of the thymus gland in old age leads to decreased immunity.

Topic: Biology, Human Health and Diseases, NEET
During osmosis, flow of water through a semipermeable membrane is:

Options:
A from solution having lower concentration only
B from solution having higher concentration only
C from both sides of semipermeable membrane with equal flow rates
D from both sides of semipermeable membrane with unequal flow rates

The correct answer is:
from both sides of semipermeable membrane with unequal flow rates

Solution:
Osmosis is the phenomenon of flow of pure solvent from the solvent to the solution or from a less concentrated solution to a more concentrated solution through a semipermeable membrane. Common semipermeable membranes are permeable to certain solute particles also. Infact, there is no perfect semipermeable membrane. Therefore, we can say that flow of water through a semipermeable membrane takes place both sides with unequal rates.

Topic: Chemistry, Solutions, NEET, NEET 2006
During oxygen transport, the oxyhaemoglobin at the tissue level liberates oxygen to the cells because

Options:
A O2 concentration is high and CO2 is low
B O2 concentration is low and CO2 is high
C O2 tension is low and CO2 tension is high
D O2 tension is high and CO2 tension is low

The correct answer is:
O2 tension is low and CO2 tension is high

Solution:
Due to low oxygen tension and high carbon dioxide tension, oxyhaemoglobin at the tissue level liberates the oxygen to the cells. This oxyhaemoglobin after reaching tissue dissociates into oxygen and haemoglobin because the amount of oxygen in tissue is low. Oxygen dissociates from the haemoglobin and diffuses into the tissue.

Topic: Biology, Breathing and Exchange of Gases, NEET
During performing the Meselson and Stahl's experiments, 15N was distinguished by 14N by

Options:
A Centrifugation in CsCl density gradient
B Paper chromatography
C Radioactivity counters
D ELISA.

The correct answer is:
Centrifugation in CsCl density gradient

Solution:
Meselson and Stahl first proved the semi -conservative replication of DNA in E.coli. Later on it was also
proved in plant and animal cells. E. coli divides in every 20 minutes. It means that DNA in E.coli replicates
in every 20 minutes. 15N is the heavy isotope (not a radioactive isotope) of the nitrogen which can be
distinguished from the normal nitrogen ( 14N ).
DNA with 15N - Heavy DNA.
DNA with 14N - Light DNA.
DNA with 15N can be distinguished from the DNA with 14N by centrifugation in a CsCl (cesium chloride)
density gradient.

Topic: Biology, Molecular Basis of Inheritance, NEET
During photophosphorylation in accordance with lysis of water the following reaction takes place:

H 2 O + H 3 PO 4 + ADP + NADP â light NADPH 2 + ATP + 'X'. where X is

Options:
A 1 2 O 2
B H 2 O
C O 2
D H +

The correct answer is:
1 2 O 2

Solution:
On photolysis, the water splits into proton and hydroxyl ion, which recombines to form oxygen.

Topic: Biology, Photosynthesis in Higher Plants, NEET
During photorespiration, 25% of the carbon is lost in

Options:
A chloroplast
B mitochondria
C peroxisome
D nucleus

The correct answer is:
mitochondria

Solution:
At high temperature and low concentration of carbon dioxide, C3 plants undergo photorespiration. In photorespiration, instead of carbon dioxide, atmospheric oxygen combines with RuBP (5C) to form one molecule of 3-PGA (3C) and One molecule of phospho-glycolate (2C) in the chloroplast. 3-PGA enters the Calvin cycle, while phospho-glycolate gets dephosphorylated to form glycolate (2C) which is then transported to the peroxisomes. In the peroxisomes, glycolate (2C) gets oxidized to form glyoxylate(2C) and hydrogen peroxide. Glyoxylate then gets converted to amino acid glycine (2C) which is transported to mitochondria. In the mitochondria, two molecules of amino acid glycine (2C)combine to form one molecule of amino acid serine (3C) and release one molecule of Carbon dioxide. Thus, 4 C atoms (of glycine) lose 1 carbon atom for the formation of 3C serine. Thus, 1 out of 4 carbon (25%) is lost at mitochondria.

Topic: Biology, Photosynthesis in Higher Plants, NEET
During photorespiration, the decarboxylation reaction occurs in

Options:
A Peroxisomes
B Mitochondria
C Chloroplast
D Chloroplast of bundle sheath cell

The correct answer is:
Mitochondria

Solution:
In mitochondria, glycine (2 molecules) is converted into serine (one molecule) & CO2.

Topic: Biology, Photosynthesis in Higher Plants, NEET
During photorespiration, the oxygen consuming reaction (s) occur in:

Options:
A stroma of chloroplasts
B stroma of chloroplasts and mitochondria
C stroma of chloroplasts and peroxisomes
D grana of chloroplasts and peroxisomes

The correct answer is:
stroma of chloroplasts and peroxisomes

Solution:
The first reaction of photorespiration occurs in the stroma of chloroplasts. In this reaction, $\mathrm{RuBisCO}$ in the presence of oxygen shows oxygenase activity. In peroxisomes, the glycolate transferred from chloroplasts takes up $\mathrm{O}_2$ and forms the glyoxylate, whereas $\mathrm{H}_2 \mathrm{O}_2$ is released as a byproduct.

Topic: Biology, Photosynthesis in Higher Plants, NEET, NEET 2006
During photorespiration, the oxygen-consuming reaction(s) occur in

Options:
A Stroma of chloroplasts and peroxisomes
B Grana of chloroplasts and peroxisomes
C Stroma of chloroplasts
D Stroma of chloroplasts andmitochondria

The correct answer is:
Stroma of chloroplasts and peroxisomes

Solution:
Photorespiration is the process that occurs in C3 plants. In this process, peroxisomes, chloroplast, and mitochondria take part. The oxygen-consuming reactions occur in peroxisomes and stroma of chloroplast while CO2 releasing reaction occurs in mitochondria.

Topic: Biology, Photosynthesis in Higher Plants, NEET
During photosynthesis, light saturation is observed at _________ of full sunlight.

Options:
A 2%
B 5%
C 10%
D 15%

The correct answer is:
10%

Solution:
There is a linear relationship between incident light and CO2 fixation rates at low light intensities. At higher light intensities, gradually the rate does not show further increase as other factors become limiting. Light saturation occurs at 10 per cent of the full sunlight. Hence, except for plants in shade or in dense forests, light is rarely a limiting factor in nature. Increase in incident light beyond a point causes the breakdown of chlorophyll and a decrease in photosynthesis.

Topic: Biology, Photosynthesis in Higher Plants, NEET
During photosynthesis, the oxygen from CO2 is incorporated into

Options:
A Oxygen gas
B water
C carbohydrates
D NADPH2

The correct answer is:
carbohydrates

Solution:
The general word formula for photosynthesis is -
6CO2+12H2O→ C6H12O6+6H2O+6O2 in presence of light and chlorophyll. The whole photosynthesis process is divided into two broad parts -
Light reaction where the light energy is used to generate ATP and NADPH2 which is later used in the Dark reaction to reduce carbon dioxide into glucose (carbohydrate) molecule. The free oxygen released as a byproduct in the photosynthesis occurs by splitting water. The oxygen of the carbon dioxide is used in making the glucose molecule through the Calvin cycle.

Topic: Biology, Photosynthesis in Higher Plants, NEET
During photosynthesis

Options:
A Both CO2 and water get oxidized
B Both CO2 and water get reduced
C Water is reduced and CO2 is oxidized
D CO2 gets reduced and H2O gets oxidized

The correct answer is:
Both CO2 and water get oxidized

Solution:
Photosynthesis is an anabolic process occurring in certain species of bacteria, protists and plants. It involves use of carbon dioxide and water to form sugars and oxygen. During the process of photosynthesis carbon dioxide from the atmosphere gets fixed through reduction reaction to form sugars and water is the source of oxygen released during the process.

Topic: Biology, Photosynthesis in Higher Plants, NEET
During prolonged fasting, in what sequence the following organic compounds are used up by the body?

Options:
A First carbohydrates, next proteins and lastly lipids.
B First fats, next carbohydrates and lastly proteins
C First carbohydrates, next fats and lastly proteins
D First proteins, next lipids and lastly carbohydrates

The correct answer is:
First carbohydrates, next fats and lastly proteins

Solution:
Carbohydrates, proteins and fats are digested in the intestine, where they are broken down into their basic units: carbohydrates into sugars, proteins into amino acids and fats into fatty acids and glycerol.

Topic: Biology, Digestion and Absorption, NEET
During prolonged fastings, in what sequence are the following organic compounds used up by the body ?

Options:
A first carbohydrates, next fats and lastly proteins
B first fats, next carbohydrates and lastly proteins
C first carbohydrates, next proteins and lastly lipids
D first proteins, next lipids and lastly carbohydrates

The correct answer is:
first carbohydrates, next fats and lastly proteins

Solution:
During prolonged fasting, first carbohydrates are used up then fats and proteins are used last. Carbohydrate and fat metabolism can produce energy more easily than protein and they follow a more or less simple pathway to enter into TCA cycle. When all carbohydrates of the body are used up then fats are converted into carbohydrates and when all fats are used up then ultimately proteins of the body are converted into carbohydrates to be used up by the body.

Topic: Biology, Biomolecules (B), NEET, NEET 2003
During protein synthesis, ribosome is found to be performing which of the following jobs?

Options:
A assemble amino acids in a chain
B carry a copy of a gene to the cytoplasm
C contain the code for the synthesis of a protein
D determine the order of bases in the protein

The correct answer is:
assemble amino acids in a chain

Solution:
Ribosome holds the mRNA containing the triplet codes for amino acid and arranges the amino acid in a chain during the process of translation where tRNA brings in the specific amino acid based on the codon sequence.

Topic: Biology, Molecular Basis of Inheritance, NEET
During protein synthesis which of the following is TRUE?

Options:
A Mn++ is required for completion of ribosome
B 3' of mRNA enters the ribosome
C 23s rRNA in bacteria is the enzyme ribozyme that act as catalyst for the formation of peptide bond.
D EF - Ts helps on codon- anticodon recognition.

The correct answer is:
23s rRNA in bacteria is the enzyme ribozyme that act as catalyst for the formation of peptide bond.

Solution:
The biosynthesis of protein inside a living cell is called translation. This process occurs in the cytoplasm where the ribosome is present. Bacteria have a 70s ribosome that is made up of smaller subunit i.e.30s and bigger subunit i.e.50s.30s subunit has 16s rRNA (ribonucleic acid) and 50s subunit has 23s rRNA and 5s rRNA in which 23sRNA has peptidyl transferase activity that catalyzes the formation of the peptide bond.

Topic: Biology, Molecular Basis of Inheritance, NEET
During rDNA technology, which one of the following enzymes is used for cleaving DNA molecule?

Options:
A Exonuclease
B Endonuclease
C Restriction endonuclease
D Helicase

The correct answer is:
Restriction endonuclease

Solution:
DNA technology restriction endonuclease enzyme is used for cleaving DNA molecules. RENs are the enzymes that recognize the palindromic sequences of DNA and cuts the phosphodiester bonds between the nucleotides. This results in the formation of DNA fragments.

Topic: Biology, Biotechnology - Principles and Processes, NEET
During refining of liquid iron to steel, CaO plays various roles, out there which of the following is most important

Options:
A To make a slag with SiO2 formed
B To prevent oxidation of sulphur
C To prevent higher concentration of phosphorus in steel
D To make a very fluid slag

The correct answer is:
To prevent higher concentration of phosphorus in steel

Solution:
During refining of liquid iron to steel, CaO plays vital role to prevent higher concentration of phosphorus in steel.

Topic: Chemistry, General Principles and Processes of Isolation of Metals, NEET
During replication of a bacterial chromosome DNA synthesis starts from a ori site and:

Options:
A RNA primers are involved
B is facilitated by telomerase
C moves in one direction of the site
D moves in bi-directional way.

The correct answer is:
moves in bi-directional way.

Solution:
Bacterial chromosomes are circular. DNA replication begins at certain fixed unique points and is called origin. In bacteria, replication occurs in bidirectional way and two separated strands between the two forks appear as a bubble under the microscope.
So, the correct answer is 'Moves in bi-directional way'.

Topic: Biology, Molecular Basis of Inheritance, NEET, NEET 2004
During replication of a bacterial chromosome DNA synthesis starts from a replication origin site and

Options:
A RNA primers are involved
B Is facilitated by telomerase
C Moves in one direction
D Moves in a bi-directional way

The correct answer is:
Moves in a bi-directional way

Solution:
Replication begins at the 'Ori' site, the origin of replication and proceeds on both sides. RNA primers are involved in both prokaryotes and eukaryotes to lay a short stretch of RNA nucleotides of 9-12 to initiate polymerization. In eukaryotes, the telomerase enzyme acts to terminate the replication process.

Topic: Biology, Molecular Basis of Inheritance, NEET
During scattering of light, the amount of scattering is inversely proportional to ......of the wavelength of light.

Options:
A Square
B Fourth power
C Half
D Cube

The correct answer is:
Fourth power

Solution:
During scattering of light, the amount of scattering is inversely proportional to fourth power of wavelength of light i.e. I∝1λ4

Topic: Physics, Wave Optics, NEET
During seed germination its stored food is mobilised by

Options:
A ethylene
B cytokinin
C ABA
D gibberellin

The correct answer is:
gibberellin

Solution:
Gibberellin induces aleurone cells to secrete enzyme to break stored food in seed. Cytokinines promote nutrient mabilisation, which helps in the delay of leaf senescence. ABA plays an important role in seed development, maturation and dormancy. Ethylene induces fruit ripening, breaks seed dormancy,

Topic: Biology, Plant - Growth and Development, NEET, NEET 2013 (All India)
During sewage treatment, which group of microbes are used to reduce BOD of sewage water

Options:
A Autotrophic , aerobic
B Heterotropic, anaerobic.
C Heterotrophic, aerobic.
D Heterotropic and autotropic both

The correct answer is:
Heterotrophic, aerobic.

Solution:
BOD is indirect measurement of quantity of organic matter present in water. It is amount of oxygen required to degrade the organic matter present in water by aerobic heterotrophic microbes. Heterotropic microbes grows aerobically and causes growth of flocs, decreasing the BOD.

Topic: Biology, Microbes in Human Welfare, NEET
During sexual reproduction in angiosperm, the megaspore is produced by:

Options:
A Mitosis
B Meiosis
C Mitosis followed by meiosis
D Meiosis followed by mitosis

The correct answer is:
Meiosis

Solution:
In young ovules, a single hypodermal cell is differentiated to archesporium cell, which may or may not cut off some parietal cells, and then becomes cell undergoing meiosis to form four haploid megaspores arranged in a linear vertical row.

Topic: Biology, Sexual Reproduction in Flowering Plants, NEET