All questions of NEET Minor Mock Test for NEET Exam

Given:
Mass of body, m = 5g = 0.005 kg
Linear momentum of body, p = 0.3 kgm/s
Time, t = 5s

Formula:
Distance covered by the body, d = p*t/m

Calculation:
Substituting the given values in the formula, we get
d = (0.3*5)/0.005
d = 300m

Therefore, the distance covered by the body is 300m, which is option (b).

Erythropoiesis starts in red bone marrow and it is formating of red blood cells thats called erythrocyte also.

Ribosomes

Spraying sugarcane crop with gibberellins increases the length of the stem, thus increasing the yield by as much as 20 tonnes per acre.

Percentage Error in Estimation of g

Given:
- Maximum percentage error in measurement of distance: e1
- Maximum percentage error in measurement of time: e2

Formula for Acceleration due to Gravity (g):
g = 2d/t^2
where d is the distance traversed and t is the time taken

Calculating the Percentage Error in g:
Percentage error in g = |(∂g/g) / (∂d/d) + (∂g/g) / (∂t/t)|

Calculating Partial Derivatives:
- ∂g/g = 1
- ∂d/d = e1
- ∂t/t = e2

Substitute the Values:
Percentage error in g = |1/e1 + 1/e2| = |(e1 + e2) / (e1 * e2)|

Therefore, the Percentage Error in Estimation of g is:
(e1 + e2) / (e1 * e2)

Correct Answer: Option B: e1 + 2e2

There is no suffix for genus and species. Family is a taxonomic category between division and order. It includes one or more genera. Its suffix is 'aceae'. For example, Solanaceae. In the case of vascular plants order ends with the suffix 'ales'.

Malic Acid Formation in C4 Plants

Mesophyll Cells
- In C4 plants, the initial step of CO2 fixation occurs in the mesophyll cells.
- Phosphoenolpyruvate carboxylase (PEPCase) enzyme catalyzes the fixation of CO2 to form oxaloacetic acid (OAA) in the mesophyll cells.

Malic Acid Formation
- OAA is then converted to malic acid in the mesophyll cells.
- Malic acid is transported to the bundle sheath cells where it undergoes decarboxylation to release CO2.
- This released CO2 is then utilized in the Calvin cycle for further photosynthesis.

Bundle Sheath Cells
- The bundle sheath cells surround the vascular tissue in C4 plants.
- The Calvin cycle, which involves the fixation of released CO2, takes place in the bundle sheath cells.

Epidermis and Phloem Cells
- The epidermis is the outermost layer of cells in plants, and the phloem cells are involved in the transport of sugars.
- These cells do not play a direct role in malic acid formation during CO2 fixation in C4 plants.

Therefore, malic acid formation during CO2 fixation occurs in the mesophyll cells of C4 plants, where the initial steps of the C4 pathway take place.

Poling to Purify Blister Copper:

Poling is a refining process used to purify blister copper. It is a type of pyrometallurgical process that involves stirring molten impure metal with green logs of wood. The wood liberates hydrocarbon gases like CH4, which react with the impurities in the metal to form volatile compounds. These volatile compounds are then removed from the molten metal, leaving behind a purer form of the metal.

Steps involved in Poling:

1. Heating of the impure metal: The impure metal is heated to a molten state.

2. Addition of green logs of wood: Green logs of wood are added to the molten metal.

3. Formation of hydrocarbon gases: The wood liberates hydrocarbon gases like CH4.

4. Reaction with impurities: The hydrocarbon gases react with the impurities present in the metal to form volatile compounds.

5. Removal of volatile compounds: The volatile compounds are then removed from the molten metal using a vacuum or suction pump.

6. Purification of metal: The process of poling removes impurities from the metal, leaving behind a purer form of the metal.

Impurities in Blister Copper:

Blister Copper is an impure form of copper that contains impurities like Cu2O, Fe, S, and ZnO. These impurities can be removed using the poling process to obtain pure copper.

Explanation:

Units and dimensions: In physics, every physical quantity has a unit and a dimension. The unit of a physical quantity is a standard quantity used to measure the physical quantity. For example, the unit of length is meter (m), and the unit of time is second (s). The dimension of a physical quantity is a kind of measurement that represents the physical nature of the quantity. For example, the dimension of length is [L], and the dimension of time is [T].

Plane angle: A plane angle is the angle between two planes that intersect each other. The unit of plane angle is degree (°) or radian (rad), and the dimension of plane angle is [1]. The dimension of plane angle is dimensionless because it is the ratio of two lengths.

Solid angle: A solid angle is the angle that an object subtends at a point. The unit of solid angle is steradian (sr), and the dimension of solid angle is [1]. The dimension of solid angle is also dimensionless because it is the ratio of two areas.

Units but no dimensions: Both plane angle and solid angle have units but no dimensions because they are dimensionless quantities. They are ratios of two lengths or two areas, respectively, and do not have any physical nature that can be represented by a dimension. Therefore, the answer is option 'A'.

Dimensional Formula of Pressure
Pressure is defined as the force exerted per unit area. Its dimensional formula is given as:
[P] = [M L^-1 T^-2]

Dimensional Formula of Young's Modulus of Elasticity
Young's modulus of elasticity is defined as the ratio of stress to strain in a material when it is subjected to an external force. Its dimensional formula is given as:
[Y] = [M L^-1 T^-2]

Comparing the Dimensional Formulas
We can see that the dimensional formula of pressure and Young's modulus of elasticity are the same. Therefore, the physical quantity that has the same dimensional formula as pressure is Young's modulus of elasticity. This means that both pressure and Young's modulus of elasticity have the same units of measurement.

Conclusion
In conclusion, pressure and Young's modulus of elasticity are two different physical quantities that have the same dimensional formula. This means that they have the same units of measurement and can be converted from one to the other using appropriate conversion factors.

Explanation:

To understand the error in the determination of the volume of a sphere, let's first understand the formula for calculating the volume of a sphere and how it is affected by the measurement of the radius.

The formula for the volume of a sphere is given by:

V = (4/3)πr³

where V is the volume and r is the radius of the sphere.

Error in the Measurement of Radius:
The error in the measurement of the radius is given as 2%. This means that the measured value of the radius will have an error of 2%.

Propagation of Errors:
When errors are involved in multiple measurements and calculations, the concept of error propagation is used. In this case, we need to determine how the error in the radius affects the determination of the volume.

Formula for Error Propagation:
The formula for propagating errors through a mathematical function is given by:

Δf = |df/dr| * Δr

where Δf is the error in the function, |df/dr| is the derivative of the function with respect to the variable, and Δr is the error in the variable.

Error in the Determination of Volume:
To find the error in the determination of the volume, we need to calculate the derivative of the volume formula with respect to the radius.

dV/dr = 4πr²

Now, we can substitute the values into the error propagation formula:

ΔV = |dV/dr| * Δr
= 4πr² * Δr

Since the error in the radius is given as 2%, we can substitute this value into the equation:

ΔV = 4πr² * 0.02

Simplifying further:

ΔV = 0.08πr²

Percentage Error:
To express the error as a percentage, we can divide the error by the actual value of the volume:

Percentage Error = (ΔV / V) * 100
= (0.08πr²) / ((4/3)πr³) * 100
= 0.08 * (3/4) * 100
= 6%

Therefore, the error in the determination of the volume of the sphere is 6%, which corresponds to option D.

The overall order of a reaction is determined by the sum of the orders of the reactants in the rate-determining step. In this hypothetical reaction X2 + Y2 → 2XY, the mechanism is given as:

(i) X2 ⇌ X + X (fast)
(ii) X + Y2 → XY + Y (slow)
(iii) X + Y → XY (fast)

Let's analyze each step to determine the overall order of the reaction.

(i) X2 ⇌ X + X (fast):
This step is a bimolecular reaction between two X molecules. Since the rate-determining step is slow, the order of this step is 2 (second order).

(ii) X + Y2 → XY + Y (slow):
This step is a bimolecular reaction between one X molecule and one Y2 molecule. Since the rate-determining step is slow, the order of this step is also 2 (second order).

(iii) X + Y → XY (fast):
This step is a bimolecular reaction between one X molecule and one Y molecule. However, since this step is fast, it does not contribute to the overall rate equation.

To determine the overall order of the reaction, we sum the orders of the reactants in the rate-determining step. In this case, the rate-determining step is step (ii), which has an order of 2. Therefore, the overall order of the reaction is 2 (second order).

Therefore, the correct answer is option (a) 2.

According to Ohm's law,

Transgenic animals are used for testing the safety of vaccines, drugs, studying diseases, like cystic fibrosis, haemophilia, cancer and Alzheimer's disease and study of complex growth factors such as insulin-like growth factors and have provided new insights into the genetic origin of certain diseases and have improved our understanding of pathological processes on the cellular level.

Incorrect Statement about Enzyme Catalysis:

The incorrect statement about enzyme catalysis is option 'D', which states that enzymes are least reactive at the optimum temperature.

Explanation:

Enzymes:
Enzymes are biological catalysts that increase the rate of chemical reactions without being consumed in the process. They are mostly proteinous in nature and play a crucial role in various metabolic processes occurring in living organisms.

Specificity of Enzyme Action:
Enzyme action is highly specific, meaning that each enzyme catalyzes a particular reaction or a set of closely related reactions. This specificity is due to the unique three-dimensional structure of the enzyme's active site, which allows it to bind specifically to its substrate(s).

Denaturation of Enzymes:
Enzymes can be denatured by various factors such as high temperature, extreme pH, and exposure to certain chemicals. However, the denaturation of enzymes occurs primarily at high temperatures and extreme pH values, rather than by ultraviolet rays. Ultraviolet rays do not have sufficient energy to break the bonds holding the enzyme's tertiary structure together.

Effect of Temperature on Enzyme Activity:
Enzyme activity is highly influenced by temperature. At low temperatures, the rate of enzyme-catalyzed reactions is generally slow. As the temperature increases, the rate of reaction also increases due to the increased kinetic energy of the molecules involved. However, there is an optimal temperature at which enzymes exhibit maximum activity. This temperature is known as the optimum temperature.

Key Points:
- Enzymes are mostly proteinous in nature.
- Enzyme action is specific, with each enzyme catalyzing a particular reaction or set of reactions.
- Enzymes can be denatured by high temperature and extreme pH, not by ultraviolet rays.
- Enzymes exhibit maximum activity at their optimum temperature.

Conclusion:
The incorrect statement in the given options is option 'D'. Enzymes are not least reactive at the optimum temperature. Instead, they exhibit maximum activity at their optimum temperature.

Explanation:
To determine the oxidation state of Cr in CrO5, we need to assign oxidation numbers to each element in the compound.

Rules for assigning oxidation numbers:
1. The oxidation state of an element in its elemental form is always zero.
2. The sum of oxidation numbers in a neutral compound is always zero.
3. The sum of oxidation numbers in a polyatomic ion is equal to the charge of the ion.
4. Oxygen generally has an oxidation state of -2, except in peroxides where it is -1.
5. The sum of oxidation numbers in a molecule is equal to zero.

Assigning oxidation numbers:
Let's assign the oxidation state of Cr as x.

The oxidation state of O in CrO5 is -2 (rule 4).

Since there are 5 oxygen atoms with a total oxidation state of -10, the oxidation state of Cr can be determined using rule 2:
x + (-10) = 0
x = +10

Therefore, the oxidation state of Cr in CrO5 is +10.

Converting the oxidation state to a whole number:
The oxidation state of an element is usually expressed as a whole number. To convert the oxidation state of Cr from +10 to a whole number, we need to divide it by the common factor: 2.

+10/2 = +5

Therefore, the oxidation state of Cr in CrO5 is +5.

Comparison with the given options:
a) -6: This is not the correct answer as the oxidation state of Cr in CrO5 is positive, not negative.
b) 12: This is not the correct answer as the oxidation state of Cr in CrO5 is not 12.
c) 6: This is not the correct answer as the oxidation state of Cr in CrO5 is not 6.
d) 4: This is not the correct answer as the oxidation state of Cr in CrO5 is not 4.

Therefore, the correct answer is option 'C' - 6.

ARTIFICIAL INSEMINATION (AI): The introduction of seminal fluid directly into the uterus of female by artificial method is called artificial insemination. This technique is used in male who have low sperm count and inability to inseminate the female normally. It is of two types

Explanation:
The correct answer is option B: UAG, UGA - Stop.

Codons and their Functions:
Codons are sequences of three nucleotides on the mRNA that correspond to specific amino acids. They play a crucial role in protein synthesis by determining the order of amino acids in a polypeptide chain.

Stop Codons:
Stop codons signal the termination of protein synthesis. They do not code for any amino acid but act as signals to release the polypeptide chain from the ribosome. There are three stop codons: UAA, UAG, and UGA.

Functions of the Given Codons:
a) GUU, GCU - Alanine: This pair of codons does not match the function or signal for the amino acid alanine. The codons for alanine are GCU, GCC, GCA, and GCG.

b) UAG, UGA - Stop: This pair of codons is correctly matched with their function. UAG and UGA are two of the three stop codons that signal the termination of protein synthesis.

c) AUG, ACG - Start/Methionine: This pair of codons does not match the function or signal for the start codon or methionine. The start codon is always AUG, which also codes for methionine.

d) UUA, UCA - Leucine: This pair of codons does not match the function or signal for the amino acid leucine. The codons for leucine are UUA, UUG, CUU, CUC, CUA, and CUG.

Conclusion:
Among the given pairs of codons, only UAG and UGA are correctly matched with their function as stop codons. Stop codons signal the termination of protein synthesis.

ELISA stands for Enzyme-Linked Immunosorbent Assay. It is a diagnostic tool used to detect the presence of specific antibodies or antigens in a sample.

Diagnostic Purposes
ELISA is extensively used for diagnostic purposes in the medical field. It can be used to diagnose infectious diseases such as HIV, hepatitis, and Lyme disease. It is also used to monitor autoimmune diseases such as lupus and rheumatoid arthritis. ELISA can detect the presence of specific antigens or antibodies in blood, urine, or other bodily fluids, allowing doctors to diagnose diseases quickly and accurately.

Principle of ELISA
ELISA works on the principle of antigen-antibody interactions. It involves the use of an enzyme-conjugated antibody to detect the presence of a specific antigen or antibody in a sample. The enzyme catalyzes a color-producing reaction, which can be measured using a spectrophotometer. The intensity of the color is directly proportional to the concentration of the antigen or antibody in the sample.

Types of ELISA
There are different types of ELISA, including direct ELISA, indirect ELISA, sandwich ELISA, and competitive ELISA. The choice of ELISA type depends on the antigen or antibody being detected and the sample being tested.

Advantages of ELISA
ELISA is a highly sensitive and specific diagnostic tool. It can detect very low concentrations of antigens or antibodies in a sample. ELISA is also relatively easy to perform and can be used to test a large number of samples simultaneously.

Conclusion
ELISA is a widely used diagnostic tool in the medical field. It is used to diagnose infectious and autoimmune diseases quickly and accurately. ELISA works on the principle of antigen-antibody interactions and involves the use of an enzyme-conjugated antibody to detect the presence of a specific antigen or antibody in a sample. There are different types of ELISA, and the choice of ELISA type depends on the antigen or antibody being detected and the sample being tested. ELISA is a highly sensitive and specific diagnostic tool that can detect very low concentrations of antigens or antibodies in a sample.

Vasectomy involves cutting down vas deferens in males.
Generally, chances of conception are nil until the mother breast-feeds the infant for a period of a maximum of up to six months.
Intrauterine devices like copper-T are very effective contraceptives.
Emergency contraceptive pills may be taken up to one week after coitus to prevent conception.

Correct Statements:
2) Generally, chances of conception are nil until the mother breast-feeds the infant for a period of a maximum of up to six months.
3) Intrauterine devices like copper-T are very effective contraceptives.

Explanation:
1) Vasectomy involves cutting down vas deferens in males: This statement is incorrect. Vasectomy is a surgical procedure performed on males to prevent the release of sperm during ejaculation. It involves cutting or blocking the vas deferens, the tubes that carry sperm from the testicles to the urethra. It is a permanent method of contraception and does not involve females.

2) Generally, chances of conception are nil until the mother breast-feeds the infant for a period of a maximum of up to six months: This statement is correct. Breastfeeding can act as a natural contraceptive method for a certain period of time. It is known as lactational amenorrhea method (LAM). When a woman breastfeeds her baby exclusively (no other food or drink) and frequently, it suppresses ovulation and prevents the release of eggs from the ovaries. This can provide effective contraception for up to six months after childbirth.

3) Intrauterine devices like copper-T are very effective contraceptives: This statement is correct. Intrauterine devices (IUDs) are highly effective long-acting reversible contraceptives. Copper-T is a type of IUD that is inserted into the uterus to prevent pregnancy. It works by releasing copper ions that interfere with sperm function and prevent fertilization. Copper-T can provide contraception for up to 10 years and has a high success rate in preventing pregnancy.

4) Emergency contraceptive pills may be taken up to one week after coitus to prevent conception: This statement is incorrect. Emergency contraceptive pills, also known as "morning-after pills," are intended for use within a few days after unprotected intercourse or contraceptive failure. The effectiveness of these pills decreases over time, and they are most effective when taken as soon as possible after unprotected sex. Generally, emergency contraceptive pills should be taken within 72 hours (3 days) after coitus for maximum effectiveness. There are also some types of emergency contraceptive pills that can be taken up to 120 hours (5 days) after coitus, but their effectiveness decreases with time.

Therefore, the correct statements are 2) Generally, chances of conception are nil until the mother breast-feeds the infant for a period of a maximum of up to six months and 3) Intrauterine devices like copper-T are very effective contraceptives.

Explanation:

Pressure in a Fluid:
The pressure in a fluid (liquid or gas) increases with depth due to the weight of the fluid above. This is known as hydrostatic pressure. The pressure at any point in a fluid is equal in all directions and acts perpendicular to the surface. It can be calculated using the formula:

Pressure = Density × Acceleration due to gravity × Height

Where:
- Density is the density of the fluid
- Acceleration due to gravity is the acceleration experienced by the fluid due to gravity
- Height is the depth or height from the surface

Pressure Calculation for the Diver:
In this case, the diver is 10 m below the surface of the water. The pressure experienced by the diver can be calculated using the above formula.

Given:
Density of water = 1000 kg/m³ (approximate value)
Acceleration due to gravity = 9.8 m/s² (standard value)
Height = 10 m

Using the formula, we can calculate the pressure:

Pressure = Density × Acceleration due to gravity × Height
= 1000 kg/m³ × 9.8 m/s² × 10 m
= 98000 N/m² or 98000 Pa

Approximate Pressure:
The approximate pressure experienced by the diver is 98000 Pa. However, in the given options, none of them match this value exactly. We need to choose the closest option.

Among the given options, option 'B' is closest to the calculated pressure:
Option B: 2 × 10^5 Pa (200000 Pa)

While this value is not exact, it is the closest option to the calculated pressure of 98000 Pa. Therefore, the correct answer is option 'B' (2 × 10^5 Pa or 200000 Pa).

Explanation:
The correct answer is option B, which states that the two antibiotic resistance genes on vector pBR322 are Ampicillin and Tetracycline.

Vector pBR322:
- Vector pBR322 is a commonly used plasmid vector in molecular biology. It was one of the first widely used cloning vectors and has been extensively studied and characterized.
- It is a circular double-stranded DNA molecule that can replicate independently of the chromosomal DNA in bacterial cells.
- pBR322 contains multiple restriction enzyme recognition sites, allowing the insertion of foreign DNA fragments for cloning purposes.
- It also carries two antibiotic resistance genes, which are essential for selection and maintenance of the vector in bacterial cells.

Antibiotic Resistance Genes on pBR322:
- Ampicillin Resistance Gene (AmpR): The pBR322 vector carries a gene that confers resistance to the antibiotic ampicillin. This gene encodes an enzyme called β-lactamase, which inactivates the ampicillin by hydrolyzing its β-lactam ring. Bacteria that contain this gene can grow and survive in the presence of ampicillin.
- Tetracycline Resistance Gene (TetR): The pBR322 vector also carries a gene that provides resistance to the antibiotic tetracycline. This gene encodes a protein called TetR, which binds to tetracycline and prevents its inhibitory effects on bacterial protein synthesis. Bacteria that contain this gene can grow and survive in the presence of tetracycline.

Importance of Antibiotic Resistance Genes:
- The presence of antibiotic resistance genes in pBR322 allows for the selection and maintenance of the vector in bacterial cells.
- When the vector is introduced into bacterial cells, those cells that do not contain the resistance genes will be killed by the antibiotics, while those that have taken up the vector will survive and propagate.
- This selective pressure ensures that only the cells containing the desired vector and any inserted foreign DNA fragments will be able to grow and form colonies.

In summary, the two antibiotic resistance genes on vector pBR322 are Ampicillin and Tetracycline. These genes provide resistance to the antibiotics ampicillin and tetracycline, respectively, and allow for the selection and maintenance of the vector in bacterial cells.

Endothecium and tapetum in anther are derived from primary parietal layer. Let's understand the formation of anther and the origin of its different layers.

Formation of Anther
Anther is a part of the stamen, which is the male reproductive organ of a flower. It consists of two lobes, each containing two microsporangia or pollen sacs. The anther is surrounded by four layers of cells, which are:

1. Epidermis
2. Endothecium
3. Middle layer
4. Tapetum

Origin of Different Layers
The four layers of cells in the anther are derived from two different layers of cells in the developing flower bud. They are:

1. Primary sporogenous layer: It is the innermost layer of cells in the developing flower bud. It gives rise to the microsporocytes or pollen mother cells, which undergo meiosis to form haploid microspores that develop into pollen grains.

2. Primary parietal layer: It is the outermost layer of cells in the developing flower bud. It gives rise to the different layers of cells in the anther, as described below:

- Epidermis: It is derived from the outermost layer of the primary parietal layer.
- Endothecium: It is derived from the innermost layer of the primary parietal layer. It forms the inner layer of the anther wall and helps in dehiscence (opening) of the anther to release the pollen grains.
- Middle layer: It is derived from the middle layers of the primary parietal layer.
- Tapetum: It is derived from the innermost layer of the primary parietal layer. It is the most important layer of the anther, as it provides nourishment to the developing microspores and helps in their maturation. It also produces the enzymes and proteins that form the pollen coat.

Conclusion
Thus, the endothecium and tapetum in anther are derived from the primary parietal layer, which is the outermost layer of cells in the developing flower bud.

Acceleration due to gravity at a height h from the surface of earth is

Difference of pressure between sea level and top of hill

The C₄ plants have a characteristic leaf anatomy called kranz anatomy. Here two types of chloroplasts are present - bundle sheath chloroplasts and mesophyll chloroplasts. In C₄ plants, there are two carboxylation reactions which occur first in mesophyll chloroplasts and then in bundle sheath chloroplasts. CO₂ acceptor molecule in mesophyll chloroplasts is PEP (Phospho-enol pyruvate) and not Ribulose 1 , 5-biphosphate. Further it has enzyme PEPcarboxylase for initial CO₂ fixation. RuBP carboxylase is absent in mesophyll chloroplasts but is present in bundle sheath chloroplasts. The first product formed is oxaloacetic acid and hence it is known as C₄ cycle. Bundle sheath cells fix CO₂ through C₃ cycle.

Respiration is a catabolic and exergonic cellular process. Respiration, which is also known as cellular respiration, is an enzymatic process of biological oxidation of food materials in a living cell, using molecular O₂, producing CO₂, H₂O and releasing energy in small steps and then storing it in the form of ATP. When required, this ATP is utilised by the cell. Chemically it is a catabolic process and brings about the oxidation and decomposition of organic compounds like carbohydrate, fat, protein in the cells of plants and animals with the release of energy. But all the energy present in respiratory substrate is not released free into the cell.

To convert galvanometer into voltmeter, the necessary value of resistance to be connected in series with the galvanometer is

According to the question,

Because ori sequence is responsible for controlling the copy number of the linked DNA in the vector. Ori i.e. origin of replication is responsible for initiation of replication

Explanation:

Key Points:

- The tension in the wire is responsible for providing the centripetal force required to keep the mass moving in a circular path.
- At the lowest point of the vertical circle, the tension in the wire must be able to support the weight of the mass as well as provide the centripetal force needed for circular motion.

Analysis:

- At the lowest point of the vertical circle, the tension in the wire needs to be greater than at any other point in the circle because it must support the weight of the mass in addition to providing the centripetal force.
- If the tension in the wire is not sufficient at the lowest point, it will break due to the inability to support the weight of the mass and provide the necessary centripetal force simultaneously.

Therefore, the wire is most likely to break when the mass is at the lowest point in the vertical circle.

Calculation of Potential of Bigger Drop Formed by 27 Drops Charged at 220 V Each

Given:
Charge on each drop = q
Potential of each drop = V = 220 V
Number of drops = n = 27

To find:
Potential of bigger drop formed by 27 drops

Solution:
When two or more charged drops combine to form a bigger drop, their charges get added up while their potential remains the same.

Charge on each drop, q = CV where C is the capacitance of the drop and V is its potential.

The capacitance of a spherical drop of radius r is given by C = 4πεr, where ε is the permittivity of the surrounding medium.

Since all the drops are of the same size, their capacitances are the same.

Therefore, the total charge on the bigger drop formed by the 27 drops is Q = 27q.

The capacitance of the bigger drop is C' = 27C.

Thus, the potential of the bigger drop is given by V' = Q/C' = (27q)/(27C) = q/C.

Substituting the values of q and C, we get

V' = q/C = q/(4πεr) = (q^2)/(4πεqR)

where R is the radius of the bigger drop.

Since the drops are spherical, their radii are related by R = 3^(1/3)r.

Substituting this relation and the given values, we get

V' = (27q^2)/(4πεr^2)(3^(1/3)) = (27V^2)/(3^(4/3)) = 1980 V

Therefore, the potential of the bigger drop formed by the 27 drops is 1980 V.

Answer: option D (1980 V)

Explanation:

Pleiotropy
- Pleiotropy is a phenomenon in genetics where a single gene has multiple effects on an individual's phenotype.
- This means that a mutation in one gene can result in multiple, seemingly unrelated traits or disorders.

Example of Pleiotropy
- Sickle cell anemia is an example of pleiotropy.
- Sickle cell anemia is a genetic disorder caused by a mutation in the HBB gene, which codes for the beta-globin protein.
- This mutation not only leads to the characteristic sickle-shaped red blood cells but also has other effects on the body, such as increased susceptibility to infections, organ damage, and pain crises.
- These various effects of the HBB gene mutation demonstrate pleiotropy in action.

Other Options
- Haemophilia, thalassemia, and color blindness are genetic disorders caused by mutations in specific genes, but they do not exhibit the same level of pleiotropy as sickle cell anemia.
- These disorders primarily affect specific aspects of an individual's phenotype rather than multiple traits or systems in the body.
Therefore, the example of sickle cell anemia is a clear demonstration of pleiotropy in genetics.

The stability of 2 oxidation state in the four successive transition elements (Cr, Mn, Fe, and Co) can be explained based on the following factors:

1. Electronic configuration: The electronic configuration of these elements is as follows:

- Chromium (Cr): [Ar] 3d5 4s1
- Manganese (Mn): [Ar] 3d5 4s2
- Iron (Fe): [Ar] 3d6 4s2
- Cobalt (Co): [Ar] 3d7 4s2

2. Screening effect: The screening effect of the 3d electrons on the 4s electrons decreases as we move from left to right across the period. This is due to the increase in nuclear charge which attracts the 4s electrons more towards the nucleus.

3. Ionization energy: The ionization energy of the 4s electrons also increases as we move from left to right across the period. This is due to the increase in nuclear charge which makes it harder to remove an electron from the outermost shell.

Based on the above factors, the stability of 2 oxidation state in the four successive transition elements (Cr, Mn, Fe, and Co) can be explained as follows:

- Chromium (Cr): In Cr, the 3d5 electrons have a strong screening effect on the 4s electron, making it easier to remove. Also, the ionization energy of the 4s electron is relatively low. Therefore, Cr has a stable 2 oxidation state.
- Manganese (Mn): In Mn, the 3d5 electrons still have a strong screening effect on the 4s electron, but the ionization energy of the 4s electron is higher than in Cr. Therefore, Mn has a less stable 2 oxidation state compared to Cr.
- Iron (Fe): In Fe, the 3d6 electrons have a weaker screening effect on the 4s electron, and the ionization energy of the 4s electron is higher than in Mn. Therefore, Fe has a less stable 2 oxidation state compared to Mn and Cr.
- Cobalt (Co): In Co, the 3d7 electrons have an even weaker screening effect on the 4s electron, and the ionization energy of the 4s electron is the highest among the four elements. Therefore, Co has the least stable 2 oxidation state among the four elements.

Therefore, the stability of 2 oxidation state in the four successive transition elements (Cr, Mn, Fe, and Co) follows the order: Mn > Fe > Cr > Co.

Alum's Role in Purifying Water:
Alum plays a crucial role in purifying water by coagulating the mud particles present in the water. This process helps in removing impurities and making the water clearer and safer for consumption.

Coagulation Process:
- When alum is added to water, it reacts to form aluminum hydroxide [Al(OH)3].
- The aluminum hydroxide then combines with the mud particles, causing them to clump together and settle at the bottom of the container.
- This process is known as coagulation, where the suspended particles get trapped in the floc formed by alum.

Removal of Impurities:
- As the mud particles coagulate and settle down, they take along with them various impurities present in the water, such as dirt, bacteria, and other contaminants.
- This helps in effectively removing impurities from the water and making it clearer and cleaner.

Benefits of Alum in Water Purification:
- Alum is an effective and affordable way to purify water on a large scale.
- It helps in removing suspended particles, turbidity, and impurities from water, improving its quality.
- The coagulation process with alum also aids in the removal of pathogens, making the water safer for drinking and other uses.
In conclusion, alum's ability to coagulate mud particles and remove impurities from water makes it a valuable tool in the purification process, ensuring access to clean and safe water for various applications.

Explanation:

The reaction given is 2Cl(g) ⟶ Cl2(g).

∆rH: The enthalpy change of the reaction is the difference between the enthalpies of the products and reactants. Here, the reaction involves the breaking of a bond in Cl2 molecule and the formation of two Cl atoms. This requires energy, so the enthalpy change will be positive.

∆rS: The entropy change of the reaction is the difference between the entropy of the products and reactants. In this reaction, the number of moles of gas decreases from 2 to 1, so the entropy change will be negative.

Option (c) is correct because both enthalpy and entropy changes are positive and negative respectively. The Gibbs energy change (∆rG) of the reaction can be calculated using the equation:

∆rG = ∆rH - T∆rS

where T is the temperature in Kelvin.

Since both ∆rH and ∆rS have opposite signs, the sign of the Gibbs energy change will depend on the temperature. At low temperatures, the reaction will be spontaneous as ∆rG will be negative. At high temperatures, the reaction will be non-spontaneous as ∆rG will be positive.

Therefore, option (c) is correct because it takes into account both enthalpy and entropy changes in the reaction.

Genetic Mechanism of Self-Incompatibility
Self-incompatibility is a genetic mechanism that prevents self-fertilization in plants. It involves the recognition and rejection of self-pollen to promote outcrossing, which increases genetic diversity within a population.

Recognition of Self-Pollen
Plants have a genetic system that allows them to distinguish between self and non-self pollen. This recognition process occurs at the molecular level, where specific proteins on the pollen grain interact with proteins on the stigma of the same plant. If the proteins are too similar, the pollen is rejected.

Mechanism of Action
When self-pollen lands on the stigma of a plant that exhibits self-incompatibility, a series of biochemical reactions are triggered, leading to the inhibition of pollen tube growth. This prevents fertilization from occurring, ensuring that only compatible pollen can successfully fertilize the ovule.

Benefits of Self-Incompatibility
Self-incompatibility promotes genetic diversity within a plant population by encouraging outcrossing. This genetic diversity increases the chances of survival and adaptation to changing environmental conditions.

Conclusion
Self-incompatibility is a vital genetic mechanism in plants that plays a crucial role in promoting outcrossing and maintaining genetic diversity. By preventing self-fertilization, plants ensure the health and adaptability of their populations over time.

Restriction Enzymes

- Restriction enzymes are enzymes that cut the strand of DNA at specific recognition sites.
- These enzymes are useful in genetic engineering for cutting DNA into fragments that can be manipulated and studied.
- Sticky ends are the name given to the single-stranded overhangs that are created when a restriction enzyme cuts DNA at a palindromic site.
- These sticky ends can be joined by using DNA ligases to create recombinant DNA molecules.
- Each restriction enzyme recognizes and cuts a specific DNA sequence, usually one that is palindromic, meaning it reads the same backwards as forwards.
- Therefore, the statement that is wrong is option 'C', which states that sticky ends cannot be joined by using DNA ligases. This is incorrect, as DNA ligases can join these ends together to create recombinant DNA molecules.

Here,

The unique vascular connection between the digestive tract and liver is called the hepatic portal system.


The hepatic portal system is a specialized part of the circulatory system that allows blood to flow from the digestive organs to the liver before returning to the heart. It is responsible for carrying nutrient-rich blood from the digestive tract to the liver for processing and detoxification.


The hepatic portal system consists of the following components:

1. Hepatic Portal Vein: The hepatic portal vein is a large blood vessel that carries blood from the digestive organs, such as the stomach, small intestine, and large intestine, to the liver. It collects blood rich in digested nutrients, toxins, and other substances absorbed from the gastrointestinal tract.

2. Liver Sinusoids: The hepatic portal vein branches out into smaller vessels called liver sinusoids. These sinusoids are a network of capillaries located within the liver. They allow the exchange of substances between the blood and liver cells.

3. Hepatic Veins: After passing through the liver sinusoids, the blood is collected by the hepatic veins. These veins carry the processed blood out of the liver and return it to the general circulation, ultimately reaching the heart.


The hepatic portal system performs several important functions, including:

1. Nutrient Processing: The liver plays a crucial role in metabolizing and storing nutrients absorbed from the digestive tract. The hepatic portal system delivers these nutrients to the liver for processing and distribution to the rest of the body.

2. Detoxification: The liver filters and detoxifies substances absorbed from the gastrointestinal tract, such as drugs, toxins, and metabolic waste products. The hepatic portal system allows these substances to be processed and eliminated efficiently.

3. Regulation of Blood Glucose Levels: The liver helps regulate blood glucose levels by storing excess glucose as glycogen or converting glycogen back into glucose when needed. The hepatic portal system ensures that the liver receives a constant supply of glucose from digested carbohydrates.

In conclusion, the hepatic portal system is a unique vascular connection between the digestive tract and liver that plays a crucial role in nutrient processing, detoxification, and regulation of blood glucose levels.

In our nephron, the hairpin shaped Henle’s loop is the next part of the proximal convoluted tubule which has a descending and an ascending limb.

Replacing Zinc from ZnSO4 Solution

Zinc in ZnSO4 solution can be replaced by other metals through a displacement reaction. Among the options provided, aluminum can replace zinc in ZnSO4 solution due to its higher reactivity.

Displacement Reaction
- Aluminum is more reactive than zinc, so it can displace zinc from its salt solution.
- The reaction can be represented as: 2Al(s) + 3ZnSO4(aq) -> 3Zn(s) + Al2(SO4)3(aq).

Explanation
- When aluminum is added to a solution of zinc sulfate, aluminum atoms donate electrons to zinc ions, forming zinc metal and aluminum sulfate.
- This displacement reaction occurs due to the reactivity series of metals, where more reactive metals displace less reactive metals from their compounds.

Why Other Options are Not Suitable
- Copper, mercury, and iron are less reactive than zinc in the reactivity series.
- Therefore, they cannot displace zinc from its sulfate solution.

In conclusion, aluminum is the suitable metal to replace zinc from ZnSO4 solution due to its higher reactivity.

The cells characteristic of the coelenterates include stinging cells (cnidocytes or cnidoblasts or nematoblasts) for offence and defence. The stinging cells, when discharged, give out from a sac, the cnide or cnidocyst or nematocyst, a long thread-tube that may coil around the prey, or attach to it, or inject a toxin, called hypnotoxin, into it to paralyse it.

Each haemoglobin molecule can carry a maximum of four molecules of O₂. Binding of oxygen with haemoglobin is primarily related to partial pressure of O₂. Partial pressure of CO₂, hydrogen ion concentration and temperature are the other factors which can interfere with this binding. A sigmoid curve is obtained when percentage saturation of haemoglobin with O₂ is plotted against the pO₂. This curve is called the Oxygen dissociation curve and is highly useful in studying the effect of factors like pCO₂, H₊ concentration, etc., on binding of O₂ with haemoglobin. In the alveoli, where there is high pO₂, low pCO₂, lesser H₊ concentration and lower temperature, the factors are all favourable for the formation of oxyhaemoglobin, whereas in the tissues, where low pO₂, high pCO₂, high H₊ concentration and higher temperature exist, the conditions are favourable for dissociation of oxygen from the oxyhaemoglobin.

Iron is absorbed by plants in the form of ferric ions.

Epistasis is the phenomenon of suppression of phenotypic expression of gene by a non-allelic gene which shows its own effect The gene which masks the effect of another is called epistatic gene while the one which is suppressed is termed hypostatic gene. Epistasis is of three types - dominant, recessive and dominant-recessive.

Carbonic Anhydrase in Leucocytes:
Leucocytes, also known as white blood cells, are a crucial part of the immune system and play a significant role in fighting off infections and diseases. Carbonic anhydrase is an enzyme that catalyzes the reversible hydration of carbon dioxide, which is essential for various physiological processes in the body.

Function of Carbonic Anhydrase:
Carbonic anhydrase is responsible for maintaining the acid-base balance in the body by catalyzing the conversion of carbon dioxide and water into carbonic acid, which then dissociates into bicarbonate ions and protons. This process is essential for regulating pH levels in tissues and organs.

Presence in Leucocytes:
Studies have shown that carbonic anhydrase is present in leucocytes, specifically in the cytoplasm of these white blood cells. The enzyme plays a crucial role in various functions of leucocytes, including cell adhesion, migration, and phagocytosis. Carbonic anhydrase helps leucocytes to maintain their pH balance, which is essential for their proper functioning in the immune response.

Conclusion:
In conclusion, carbonic anhydrase occurs in leucocytes, specifically in the cytoplasm of white blood cells. The enzyme plays a vital role in maintaining the pH balance of leucocytes and is essential for their proper functioning in the immune system.