IMAT 2024 Answers & Worked Solution

Full explanation

To the Lighthouse was written by Virginia Woolf, published in 1927 as one of the defining works of modernist, stream-of-consciousness fiction. Woolf is also behind Mrs Dalloway, Orlando, The Waves, and the essay A Room of One’s Own – so option D is correct.

Each wrong option names a real, well-known author, just not the right one. Mary Shelley (option B) is the author of Frankenstein; or, The Modern Prometheus, not To the Lighthouse. Emily Dickinson (option C) worked almost entirely in poetry rather than the novel form – her Complete Poems is her signature body of work. Jane Austen (option A) wrote Pride and Prejudice, and Agatha Christie (option E) is remembered for detective novels such as The Murder of Roger Ackroyd. None of these four wrote To the Lighthouse, which leaves only option D.

Full explanation

To answer this question, break down the paragraph into different parts.

The first sentence indicates that symbols for numbers existed in ancient times. (This rules out option C)

The second one suggests that the abstractness and generality were specific to the Greek era, not ancient time.

Then, it expresses that mathematics evolved slowly and deliberately. (This rules out option E)

After that, it suggests that earlier mathematics lacked generality and abstraction. and pre-greek mathematics were not communicated in a structured or methodical way. (This rules out option B)

And Lastly, it presumed that ancient mathematics was practical and application-focused. (This rules out option D)

Thus, the only option that cannot be inferred from the text is the option A.

Full explanation

The Hundred Years’ War (1337-1453) was fought between the Kingdom of France and the Kingdom of England over rival claims to the French throne and control of French territory. France ultimately prevailed, pushing the English out of nearly all their continental holdings except Calais, which held out until 1558. That makes option C the correct pairing.

The other four options all pair kingdoms that were never the war’s protagonists. Aragon and Castile (option A) were both Iberian kingdoms whose rivalries and eventual union belong to Spanish, not Anglo-French, history. Aragon and France (option B) weren’t opposing sides in this conflict either – Aragon’s political entanglements at the time were centred on the Mediterranean and Iberia. Castile and Portugal (option D) were Iberian neighbours whose own wars (such as the War of the Castilian Succession) are a separate story entirely. And England and Portugal (option E) is the most misleading pairing of all, because those two kingdoms weren’t enemies at all – the Anglo-Portuguese Alliance of 1373 made them allies, one of the oldest alliances in European history and still formally in force today.

Full explanation

A passive verb follows the pattern “to be” + past participle, with the receiver of the action as the grammatical subject and the doer (if named at all) tucked into a “by…” phrase. Everything else in this list is active: the subject performs the verb directly.

In option A, “Homer sings the deeds” – Homer is the subject and does the singing. In option B, “students read Greek tragedies” – the students are the ones doing the reading. Option C works the same way: “Julius Caesar described…his military campaign” – Caesar is the subject performing the verb. Option D follows suit: “Plato associates solid forms to the four elements” – Plato is doing the associating.

Option E flips that structure around: “The deeds of Aeneas were sung by Virgil.” Here the deeds – the thing being acted upon – sit in the subject slot, the verb is the auxiliary “were” plus the past participle “sung,” and Virgil, the actual performer of the singing, is demoted to a “by” phrase. That’s the passive voice, which makes E the answer.

Full explanation

Reading the frequency table, everyone who scored higher than 5 falls in the mark-6-through-mark-10 columns: 1 student got a 6, 2 got a 7, 2 got an 8, 1 got a 9, and nobody managed a perfect 10. That’s 1 + 2 + 2 + 1 + 0 = 6 students who passed.

To turn that into a percentage you need the whole class, which comes from adding every column in the table, not just the passing ones: 1 + 4 + 4 + 6 + 2 + 1 + 1 + 2 + 2 + 1 + 0 = 24 candidates sat the test in total.

So the pass rate is 6 out of 24, which simplifies to 1/4, or 25% – option A.

Full explanation

Start with how many pens are being handed out at all: 12% of the 1500 participants receive one, which is 0.12 × 1500 = 180 pens in total.

Those 180 pens split between silver and gold in a 2:1 ratio, so it helps to think of them as 3 equal shares: 180 ÷ 3 = 60 pens per share. That gives 120 silver pens (two shares) and 60 gold pens (one share) – gold is the rarer prize.

Shelly’s chance of walking away with a gold pen specifically is just the number of gold pens divided by the total number of participants: 60/1500 = 4% – option E.

Full explanation

Model the original price as x, and apply the two discounts one after the other rather than adding their percentages together – successive discounts don’t simply add up, because the second one is taken off an already-reduced price, not off the original.

After the first 10% discount, the price drops to 0.9x. Apply the second, 20% discount to that new, smaller price: 0.9x − 0.2(0.9x) = 0.9x × 0.8 = 0.72x.

So the final price is 72% of the original, which means the combined discount is 100% − 72% = 28% – option B. That’s short of the 30% you’d get by just adding 10% + 20% (option C), which overstates the saving because it ignores that the second cut applies to a smaller base than the first one did.

Full explanation

Since 343 = 7³, picture the big cube as a 7×7×7 stack of unit blocks – six painted faces on the outside, and a solid core buried inside where the paint never reaches.

The efficient move is to find that unpainted core first, then subtract it from the total, rather than trying to count painted blocks directly – a corner block has 3 painted faces, an edge block has 2, a face block has 1, and keeping those categories straight gets messy fast. Peel away the painted outer layer on every side and what’s left is a smaller cube, one unit shorter in each direction: 7 − 2 = 5, so the interior is 5×5×5 = 125 blocks that see no paint at all.

Every block that isn’t in that untouched interior has at least one painted face, so the answer is 343 − 125 = 218 – option E.

Full explanation

Start by pinning down exactly what the sentence claims: “When he takes the train, Marco always arrives at work on time” is the conditional Train → On Time. It says nothing at all about what happens when Marco doesn’t take the train – he might still be on time some other way, or he might not be. The only thing you’re logically entitled to derive from a conditional is its contrapositive: if the consequent fails, the antecedent must have failed too. Here that’s Late → Not Train – exactly option B.

Every wrong option tries to run the logic in a direction the original statement doesn’t support. Option A (“arrived late, therefore he took the train”) asserts Late→Train, which is nowhere near what was said. Option C (“arrived on time, therefore he missed the train”) assumes the converse – that being on time somehow requires having missed the train – which the statement never claims; being on time is consistent with having taken the train just fine. Option D (“did not take the train, therefore he arrived late”) is the denial of the antecedent, a classic invalid move: not taking the train tells you nothing about whether he was late. And option E (“took his car, therefore he arrived on time”) introduces a mode of transport the original statement never mentions at all, so nothing can be concluded about it either way.

Only the contrapositive holds up, which is why B is the answer.

Full explanation

Option A Explanation:

Cellular respiration has 4 stages which are Glycolysis, Pyruvate oxidation (formation of acetyl CoA), the citric acid cycle and the oxidative phosphorylation. The first stage occurs in the cytoplasm while the latter three stages occur in the mitochondria. Thus, this option is correct.

Option B Explanation:

Glycolysis is an anaerobic process that takes place in the cytoplasm and does not require oxygen.

Option C Explanation:

Photosynthesis takes place in chloroplasts, where sunlight, water, and carbon dioxide are converted into glucose and oxygen.

Option D Explanation:

The methylation of polysaccharides mainly occurs in the Golgi apparatus, where sugars are modified before being transported or secreted.

Option E Explanation:

Microbodies are a category of organelle that includes peroxisomes. Thus, synthesis of vesicles and organelles like microbodies mostly originates from Endoplasmic reticulum and Golgi apparatus. It is not a function of mitochondria and does not exist in the mitochondria.

Full explanation

Option A Explanation:

Hydrogen bond is an intermolecular (Secondary) bond, not a covalent bond. Intermolecular forces are the forces of attraction or repulsion between molecules. They are weaker than chemical bonds but crucial for determining physical properties like boiling point, melting point, and solubility.

Option B Explanation:

Hydrogen bond is an intermolecular bond and It can be found between Hydrogen and other electronegative atoms which can be F, N, or O, present in another molecule as stated. Thus, this option is correct.

Option C Explanation:

In general, intermolecular bonds, including hydrogen bonds, are much weaker than intramolecular bonds, which are the strong covalent or ionic bonds that hold atoms together within a molecule. Hydrogen bonds occur only between polar molecules and do not form between non-polar molecules.

Option D Explanation:

Within the water molecule, bond between hydrogen and oxygen is a covalent bonds, not a hydrogen bond. If it said the bond is between hydrogen and oxygen between water molecules, it could be true.

Option E Explanation:

Hydrogen bonds form when a hydrogen atom, covalently bonded to a highly electronegative atom like nitrogen, oxygen, or fluorine, is attracted to a lone pair of electrons on another nitrogen, oxygen, or fluorine atom in a different molecule. This requires a polar molecule with a hydrogen attached to N, O, or F and another nearby molecule with available lone pairs on these atoms.

Full explanation

Option A is correct: the Krebs cycle, also called the citric acid cycle (CAC), is an aerobic stage of cellular respiration that occurs in the mitochondrial matrix of eukaryotic cells.

Option B is false: the electron transport chain, not the Krebs cycle, occurs on the inner mitochondrial membrane.

Option C is false for eukaryotic cells: in prokaryotic cells (which lack mitochondria), the Krebs cycle occurs in the cytoplasm, but the question specifically asks about eukaryotic cells, where it takes place in the mitochondrial matrix.

Option D is false: ribosomes (including the large ribosomal subunit) are responsible for translation, where proteins are produced – not for the Krebs cycle.

Option E is false: the Krebs cycle occurs only in the mitochondrial matrix, where the needed enzymes are present and the electrons produced can directly enter the electron transport chain – not close to the plasma membrane.

Hence, the correct answer is (A).

Full explanation

Option A Explanation:

Tetroses are monosaccharides with four carbon atoms. They include aldotetroses like erythrose and ketotetroses like erythrulose. Tetroses are less common but play roles in some metabolic pathways.

Option B Explanation:

Glucose is a hexose sugar with 6 carbon atoms, while pentoses have 5 carbon atoms. Examples of pentoses include ribose, found in RNA, and deoxyribose, found in DNA.

Option C Explanation:

Trioses are simple sugars with 3 carbon atoms, such as glyceraldehyde and dihydroxyacetone, important in energy metabolism. Glyceraldehyde and dihydroxyacetone are the intermediates in the glycolysis process.

Option D Explanation:

Hexoses are monosaccharides with six carbon atoms, like glucose, fructose, and galactose. They are important energy sources and building blocks in metabolism.

Option E Explanation:

Nonoses are monosaccharides with nine carbon atoms. An example is sialic acid (N-acetylneuraminic acid), which is important in cell signaling and found on the surfaces of animal cells.

Full explanation

Option A Explanation:

Fructose is a hexose sugar with six carbon atoms and is classified as a ketose due to its ketone group. It occurs naturally in fruits, honey, and some vegetables and is sweeter than glucose. Unlike ribose, fructose is not part of RNA structure.

Option B Explanation:

Glucose is a hexose monosaccharide with six carbon atoms, classified as an aldose because it has an aldehyde group. It is a primary source of energy for cells and is found in many foods. Glucose is also a building block of polysaccharides like starch, glycogen, and cellulose.

Option C Explanation:

The monomer found in RNA is the nucleotide, which consists of ribose as the sugar unit, a phosphate group, and a nitrogenous base. Ribose is a five-carbon aldopentose sugar. Unlike RNA, DNA contains deoxyribose, a similar sugar that lacks one oxygen atom.

Option D Explanation:

Glycerol is a three-carbon alcohol with three hydroxyl groups, making it highly water-soluble. It serves as the backbone of triglycerides and phospholipids, where fatty acids attach. Glycerol is not present in the structure of RNA molecules.

Option E Explanation:

Lactose is a disaccharide composed of glucose and galactose linked by a β-1,4-glycosidic bond. It is naturally found in milk and dairy products and is broken down in the body by the enzyme lactase into its monosaccharide components for absorption.

Full explanation

Option A Explanation:

Carrier proteins are a kind of transport proteins that exist on the plasma membrane, and mRNA is transported by different mechanisms, not by carrier proteins.

Option B Explanation:

Proteins that phosphorylate enzymes in the plasma membrane are the kinase enzymes. Carrier proteins only carry materials across the membrane.

Option C Explanation:

Proteins that break down phospholipids in the plasma membrane is the phospholipidase enzyme. Carrier proteins only carry materials across the cell membrane.

Option D Explanation:

Correct. Carrier proteins are membrane proteins that transport specific molecules or ions across the cell membrane by binding to them and changing shape to move them across.

Option E Explanation:

Carrier proteins do not transport tRNA or any RNA molecules, which are moved by different nuclear export mechanisms.

Full explanation

Option A Explanation:

Cells harvest the chemical energy stored in organic molecules and use it to generate ATP, the molecule that drives most cellular work. Thus, this option is correct.

Option B Explanation:

FAD+ is an energy carrier molecule produced during the Krebs cycle which donates the electrons to the electron transport chain, contributing to the production of ATP. FADH2 is the reduced form of FAD+.

Option C Explanation:

NADH is an energy carrier molecule produced during glycolysis, the Krebs cycle, and other metabolic pathways. NADH is an electron carrier, not the direct energy currency.

Option D Explanation:

Creatine is a compound derived from amino acids. It serves as an energy storage and transfer in the tissues. However, it is not the energy currency of the cell.

Option E Explanation:

NADPH is an electron carrier mainly involved in anabolic (biosynthetic) reactions, such as fatty acid synthesis and the Calvin cycle in photosynthesis.

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Full explanation

Option A Explanation:

Lipolysis is the process of breaking down triglycerides into glycerol and fatty acids; it is not related to ATP hydrolysis.

Option B Explanation:

Endergonic reactions require an input of energy, but ATP hydrolysis is exergonic because it releases energy.

Option C Explanation:

Condensation is a reaction where two molecules join together with the release of water, while ATP hydrolysis is the opposite—it uses water to break a bond.

Option D Explanation:

Oxidation-reduction reactions involve the transfer of electrons, but ATP hydrolysis does not involve electron transfer.

Option E Explanation:

One ATP molecule releases approximately 7.3 kcal/mol (~30.5 kJ/mol) of energy upon hydrolysis, which can be used for cellular work or dissipated as heat, depending on the process. Thus, this option is true.

Full explanation

Option A Explanation:

Intercellular compartmentalization involves the organization of different cell types into specialized functions that collectively support the organism’s physiological processes. Since it involves multiple cell types to organize into specific tissues, it only occurs in multicellular organisms. Thus, this option is true.

Option B Explanation:

Viruses lead a type of borrowed life, relying entirely on host cells for replication, and are not considered true cells. As a result, they lack cellular structures and do not possess intercellular compartmentalization.

Option C Explanation:

Bacteria, which are prokaryotes, are typically unicellular organisms.

Therefore, they lack intercellular compartmentalization, as they consist of a single cell without internal membrane-bound compartments.

Option D Explanation:

Prokaryotes are typically unicellular organisms. Therefore, there is no intercellular compartmentalisation.

Option E Explanation:

Algae can be both unicellular and multicellular. However, multicellular algae usually lack true tissue differentiation. Therefore, there is no intercellular compartmentalization.

Full explanation

Option A Explanation:

The nucleus is supported by the nuclear lamina, made of intermediate filaments, not microtubules. Microtubules are part of the cytoskeleton outside the nucleus and do not form part of its structure.

Option B Explanation:

Centrioles are cylindrical cellular structures composed primarily of microtubules. They are typically arranged in a characteristic “9+0” pattern, where nine triplets of microtubules are arranged in a circle. Thus, this option is true.

Option C Explanation:

The Golgi apparatus is not composed of microtubules; it is made of stacks of flattened membrane-bound sacs called cisternae. However, microtubules help position and transport vesicles to and from the Golgi, but they are not part of its structure.

Option D Explanation:

The nucleolus is not composed of microtubules. It is a dense region inside the nucleus made of RNA, DNA, and proteins, where ribosome subunits are assembled. Microtubules are not part of its structure.

Option E Explanation:

The endoplasmic reticulum (ER) is not composed of microtubules. It is made of a network of membrane-bound tubules and sacs. While microtubules help position and organize the ER within the cell, they are not part of the ER’s structure itself.

Full explanation

Option A Explanation:

“A very selective membrane” part is correct for inner membrane but the latter part of the sentence is incorrect. On the inner membrane, there are proteins that take part in the electron transport chain.

Option B Explanation:

Mitochondria have two membranes: an outer membrane, which is smooth and not very selective, but the inner membrane is more selective.

Option C Explanation:

Mitochondria have two membranes: an outer membrane, which is smooth and encloses the organelle, and an inner membrane, which is folded into cristae to increase the surface area for energy production. Between these two membranes is the intermembrane space, which plays a role in cellular respiration.

Option D Explanation:

Mitochondria typically have two membranes: outer membrane and inner membrane. Each membrane is composed of phospholipid bilayer. Thus, this option is false.

Option E Explanation:

Mitochondria have an outer membrane, which is permeable to small molecules, and a very selective inner membrane, which controls the passage of ions and molecules and is folded into cristae to enhance energy production. Thus, this option is true.

Full explanation

Option A Explanation:

Correct. Anticodon is a sequence of three nucleotides on a tRNA molecule that is complementary to a codon on mRNA. During translation, the anticodon pairs with the mRNA codon, ensuring the correct amino acid is added to the growing polypeptide chain.

Option B Explanation:

A sequence of three nucleotides transcribed from the mRNA is a codon, not an anticodon.

Option C Explanation:

This option describes a DNA codon.

Option D Explanation:

rRNA has neither codon nor anticodon. Anticodon is on tRNA and does not directly bind amino acids (amino acids bind to the other end of tRNA).

Option E Explanation:

Sequence of three mRNA nucleotides is a mRNA codon.

Full explanation

A ribosome is built from two subunits, a large one and a small one, and each subunit is itself a mix of ribosomal RNA (rRNA) and ribosomal proteins folded together. There’s no DNA anywhere in that structure, and no membrane, so no lipid either.

That’s the flaw shared by three of the four wrong options: A (RNA and DNA), B (DNA and proteins), and E (RNA, DNA and proteins) all smuggle DNA into the ribosome, which simply isn’t there – DNA stays in the nucleus (or, in prokaryotes, the nucleoid), while the ribosome itself is assembled from RNA and protein alone. Option B additionally drops RNA entirely, which is just as wrong in the other direction, since rRNA makes up roughly two-thirds of a ribosome’s mass and does the actual catalytic work of peptide-bond formation. Option C (DNA and lipids) misses on both counts: no DNA, and no lipid either, because ribosomes aren’t membrane-bound organelles.

Only option D – RNA and proteins, nothing else – matches what a ribosome is actually made of.

Full explanation

Option A Explanation:

The Cell membrane is composed of double layer of phospholipids embedded by proteins and cholesterol. Triglyceride is involved as a component of phospholipid, and cholesterol is found wedged between phospholipid molecules. Both of these molecules do not exist as a layer. Thus, this option is false.

Option B Explanation:

Membrane proteins are embedded in the fluid matrix of the lipid bilayer. They do not exist as a separate layer. Thus, this option is false.

Option C Explanation:

Correct. The cell membrane consists of a double phospholipid layer (bilayer) with hydrophobic tails facing inward and hydrophilic heads facing outward, along with integral and peripheral proteins embedded or attached to the membrane.

Option D Explanation:

There is not a glycoprotein layer in the latest fluid mosaic model of plasma membrane. Glycoproteins and glycolipids can be found on the surface of the cell membrane toward the ECF. Thus, this option is false.

Option E Explanation:

Fatty acids and globular proteins do not exist as a separate layer. Fatty acids can be found as a component of phospholipid in the phospholipid bilayer and globular proteins are embedded in the fluid matrix of the lipid bilayer. Thus, this option is false.

Full explanation

Option A Explanation:

This option describes the process of reverse transcription. Reverse transcription is the process where RNA is converted into DNA using the enzyme reverse transcriptase. This occurs in some viruses, like retroviruses (e.g., HIV), allowing their RNA genome to be integrated into the host’s DNA.

Option B Explanation:

This option correctly describes the process of translation. Translation is the process of protein synthesis, where the ribosome reads mRNA codons and uses tRNA to bring matching amino acids, forming a polypeptide chain. It takes place in the cytoplasm.

Option C Explanation:

This option does not describe the process of translation.

Option D Explanation:

This option describes the process of transcription, not translation. Transcription is the process where DNA is used as a template to produce messenger RNA (mRNA). This occurs in the nucleus of eukaryotic cells and is carried out by the enzyme RNA polymerase, which builds the mRNA strand complementary to the DNA template.

Option E Explanation:

tRNA anticodons pair only with codons on mRNA during translation, but this alone does not fully explain the entire process of protein synthesis.

Full explanation

Option A Explanation:

The cytoskeleton is a network of fibers extending throughout the cytoplasm. The eukaryotic cytoskeleton is composed of three types of molecular structures: microtubules, microfilaments, and intermediate filament. Thus, this option is correct.

Option B Explanation:

Microtubule is a component of the cytoskeleton but myosin and filamin are not.

Option C Explanation:

Microtubule is a component of the cytoskeleton but dynein and myosin are not.

Option D Explanation:

All of these mentioned proteins are not principal components of the cytoskeleton.

Option E Explanation:

Mentioned fibres are not the principal components of the cytoskeleton.

Full explanation

An allele is one of the alternative versions of a gene that can sit at a given chromosomal locus – the reason two people can carry different versions of, say, the gene for eye colour. That’s exactly option C.

Each wrong option is actually describing a different piece of genetics vocabulary, mislabelled as “allele.” Option A restricts alleles to haploid cells, but that’s backwards – the concept of two different alleles at a locus is most meaningful in diploid organisms, which carry one allele from each parent, and ploidy has nothing to do with what an allele is. Option B – “a coding DNA base for a specific amino acid” – describes something smaller than an allele: a single amino acid is specified by a triplet of three bases (a codon), not one base, and a codon isn’t an allele either. Option D describes the phenotype, not the allele – the allele is the underlying genetic variant, which can exist and be inherited whether or not it’s actually expressed (a recessive allele hiding behind a dominant one in a heterozygote produces no phenotypic trace at all, but it’s still very much there). Option E – “a set of coding DNA triplets for a specific amino acid” – is closer to describing a gene (or over-describes a single amino acid, which needs only one triplet, not a set), not an allele, which is a variant form of that gene rather than the gene itself.

Full explanation

Option A Explanation:

In associated genes, the expression of one allele is associated by another allele. Thus, it is evident that an allele cannot certainly express itself in any condition.

Option B Explanation:

For a recessive allele to be able to express itself, it needs to be in a homozygous condition.

Option C Explanation:

Mutated alleles mean the allele is not in its normal state to be expressed. Thus, it cannot express itself.

Option D Explanation:

If a character is determined by the expression of multiple genes, it is not possible that one allele certainly expresses itself.

Option E Explanation:

According to the third concept of Mendel’s model, it is described that, if the two alleles at a locus differ (in heterozygous condition), then one, the dominant allele, determines the organism’s appearance; the other, the recessive allele, has no noticeable effect on the organism’s appearance. Thus, for a allele to be certainly expressed, it needs to be a completely dominant allele.

Full explanation

Option A Explanation:

This refers to changes in how cells divide, such as errors in mitosis or meiosis, but this is not the definition of mutation itself.

Option B Explanation:

Changes in how the cell produces or uses energy, which might be a result of a mutation, but this is not the definition of mutation itself.

Option C Explanation:

Changes in enzymes during fertilisation or early development; this is not what defines a mutation.

Option D Explanation:

Changes in how substances are actively transported across membranes, which is not related to mutations directly.

Option E Explanation:

Correct. Mutations are permanent changes in the DNA sequence, altering the genetic information of a cell, which can affect proteins and traits.

Full explanation

Option A Explanation:

This option correctly describes the process of translation. Translation is the process that leads to the synthesis of polypeptide chains from mRNA, where ribosomes read the mRNA codons and tRNA brings the corresponding amino acids to build the protein.

Option B Explanation:

In eukaryotic cells, the translation process occurs in the cytoplasm. Thus, this option is false.

Option C Explanation:

Translation leads to the synthesis of proteins from RNA. The process mentioned in which RNA molecules are synthesised from DNA is known as the transcription process.

Option D Explanation:

Transcription is a process in which mRNA is synthesised from DNA. Translation is the process that comes after transcription that leads to the synthesis of proteins from RNA. Thus, it can be seen that these two processes are not similar to each other.

Option E Explanation:

Translation occurs in both eukaryotic and prokaryotic cells. This is one of the fundamental processes of gene expression in organisms.

Full explanation

DNA base-pairing is fixed: A pairs with T, and G pairs with C. Reading straight down the given strand, C-C-G-T-T-A-T-T-G-A, and swapping each base for its partner gives G-G-C-A-A-T-A-A-C-T – which is option A.

The other four options are worth checking individually, because two of them are traps that mimic mistakes it’s easy to make by hand. Option B, AGTTATTGCC, isn’t a complement at all – it’s the original sequence CCGTTATTGA simply written back to front, with no base-pairing applied. That’s the error you get if you remember that DNA strands run antiparallel and reverse the sequence, but forget the actual point of the exercise: swapping each base for its partner. Option E, GGCAATTAAT, is closer to the truth – it matches the correct answer at every position except two, where a T and an A have been swapped near the end (…TAACT becomes …TTAAT) – the kind of transposition slip that creeps in when carrying a ten-letter sequence across by hand. Options C (GGACATCCCT) and D (CGCACCTCCT) don’t follow any recognisable pattern against the original strand at all; they’re simply incorrect base-pairings.

Full explanation

Option A Explanation:

This option describes the Transcription process, not replication.

Option B Explanation:

DNA replicates typically in the semiconservative model, in which the two strands of the parental DNA molecule separate, and each functions as a template for synthesis of a new, complementary DNA strand. Thus, this option is true.

Option C Explanation:

This option describes Mitosis or Meiosis process, not replication.

Option D Explanation:

This option describes the Translation process, not replication.

Option E Explanation:

RNA does not generally replicate itself in most biological systems.

Full explanation

Option A Explanation:

Together, the operator, the promoter, and the genes they control (the entire stretch of DNA required for expression of a specific gene) constitute an operon. Thus, it does not contain proteins.

Option B Explanation:

The group of genes involved in operon unit are dependent on each other. For example, in trp repressor, if a repressor binds to the operator, it blocks attachment of RNA polymerase to the promoter and thereby prevents transcription of the genes.

Option C Explanation:

It correctly describes the structure and function of operon unit.

Option D Explanation:

Operon unit is discovered as a basic mechanism for the control of gene expression in bacteria, in the transcription stage, by interfering with the transcription of DNA genes. Thus, the operon unit solely consists of DNA segments.

Option E Explanation:

This option describes the opposite of the function of Operon unit which is to adjust the production level of certain enzymes.

Full explanation

Dalton’s Law says the total pressure of a gas mixture is just the sum of what each gas would exert on its own – so nitrogen’s slice of that 2.4 atm is exactly proportional to nitrogen’s slice of the total moles in the container.

Add up every gas present: 0.3 mol N₂ + 0.5 mol CO₂ + 0.4 mol O₂ = 1.2 mol total. Nitrogen’s mole fraction is its own share of that total: 0.3/1.2 = 0.25 – one quarter of every gas particle bouncing around in the container is nitrogen.

Since each gas contributes to the total pressure in exactly the same proportion as its share of the moles, nitrogen accounts for exactly a quarter of the total pressure: P(N₂) = 0.25 × 2.4 atm = 0.6 atm – option C.

Full explanation

This is a question about the ideal gas law equations, specifically Gay-Lussac’s law.

Gay-Lussac’s Law states that the pressure of a given mass of gas varies directly with the absolute temperature of the gas, when the volume is kept constant.

Given: the phrase “a gas confined in a rigid cylinder” means that the gas has constant volume. Temperature is −3°C. Pressure is 9 atm.

T₁ = −3 + 273 K = 270 K, P₁ = 9 atm

T₂ = 27 + 273 K = 300 K, P₂ = ?

According to Gay-Lussac’s law,

P₁/T₁ = P₂/T₂

P₂ = (P₁ × T₂) / T₁ = (9 atm × 300 K) / 270 K = 10 atm

Full explanation

N₂O₃, SO₃, and Cl₂O are acidic oxides. They are oxides of non-metals that are placed on the top right part of the periodic table. Thus, they react with water to form acid solutions.

N₂O₃ + H₂O ⟶ 2HNO₂ SO₃ + H₂O ⟶ H₂SO₄ Cl₂O + H₂O ⟶ 2HOCl SiO₂ is a metalloid oxide and it is not soluble in water and does not react easily with water.

BaO is a basic oxide. It is the oxide of a group II alkaline earth metal.

Thus, reaction of BaO with water gives barium hydroxide.

BaO + H₂O ⟶ Ba(OH)₂

Full explanation

This is a simple stoichiometric question that involves identifying the correct mole ratio between the reactants and products.

According to the given equation, 4 moles of FeS₂ reacts with 11 moles of O₂ to give 2 moles of Fe₂O₃ and 8 moles of SO₂.

Option A has the mole ratio of the reactants reversed.

Option C has 2 moles of FeS₂ which would require 5½ mole of Oxygen instead of 5 moles.

Option D has 1 mole of FeS₂ which would require 2¾ mole of Oxygen and forms 2 moles of SO₂, not 3 mole.

Option E has 2 moles of FeS₂ and enough O₂ and forms 1 mol of Fe₂O₃ and 4 mol of SO₂ instead of 6 mole.

Option B says it has 2 moles of FeS₂ and enough O₂ and forms 1 mol of Fe₂O₃. Thus, this is the only correct option.

Full explanation

Dilution doesn’t destroy any solute – it just spreads the same amount of H₂SO₄ across more water – so the product of concentration and volume stays constant before and after: M₁V₁ = M₂V₂.

Plug in what’s known: 0.25 M × 15 mL = 0.05 M × V₂, so V₂ = (0.25 × 15)/0.05 = 75 mL. That 75 mL is the total volume of the diluted solution – not the amount of water poured in on top of what was already there.

Since the original 15 mL of solution is still part of that 75 mL, the water actually added is the difference: 75 mL − 15 mL = 60 mL – option C.

Full explanation

Start with what happens when Na₂SO₄ dissolves: it splits completely into ions, Na₂SO₄ → 2Na⁺ + SO₄²⁻, so every mole of the salt that dissolves releases two moles of sodium ions – an easy detail to overlook if you stop counting at the moles of salt itself.

Find how much salt is actually present: with a 250 mL (0.25 L) sample at 1.2 mol/L, moles of Na₂SO₄ = volume × molarity = 0.25 L × 1.2 mol/L = 0.3 mol.

Since each mole of Na₂SO₄ hands over two moles of Na⁺, the sodium-ion count is double that: 2 × 0.3 mol = 0.6 mol – option C.

Full explanation

The given acid-base reaction cannot be categorised in Bronsted Acid and Base definitions because there is not hydrogen transfer between the reactants. It does not increase the concentration of H+ or OH- either, so, this also cannot be categorised in Arrhenius’s definition. But we can use the Lewis theory of acids and bases, which explains acid-base reactions based on the transfer of electron pairs. According to this theory, a Lewis acid is defined as a substance that accepts an electron pair, while a Lewis base is a substance that donates an electron pair. This definition focuses on electron movement rather than protons, making it more general and applicable to a wider range of reactions.

NH₃ has lone pairs of electrons and BF₃ has available place for electrons in its p subshell. Thus, during the given reaction, NH₃ donates its lone pair to BF₃, making NH₃ the Lewis base.

Full explanation

Start by writing a balanced equation for what’s actually happening: Zn + HNO₃ → Zn(NO₃)₂ + NO₂ + H₂O.

Now track oxidation states across that reaction. Zinc goes from 0 (as the free metal) to +2 in Zn(NO₃)₂ – it loses electrons, so it’s being oxidised. Nitrogen, meanwhile, starts at +5 in HNO₃ and ends up split between +5 (in the nitrate ion that stays in solution) and +4 (in the NO₂ gas that’s given off) – some of the nitrogen gains an electron, so it’s being reduced.

The reducing agent is whatever gets oxidised – it’s the species that hands electrons over, enabling something else to be reduced. Since zinc is the one losing electrons here, metallic zinc, Zn(s), is the reducing species: option E.

Full explanation

The fastest way through a question like this is to build each molecular formula from its structure rather than trying to count hydrogens off a drawing, because branching and rings both remove hydrogens compared to a plain, unbranched chain.

2-Hexanol is hexane (six carbons, no rings or double bonds) with one hydrogen swapped for an -OH group – swapping H for OH doesn’t change the total hydrogen count here, since the OH group brings its own H back. That gives C₆H₁₄O, 14 hydrogens.

1,2-Dimethylcyclobutane has a four-carbon ring (which already costs two hydrogens relative to an open chain) plus two methyl branches, for six carbons total and one ring: C₆H₁₂, 12 hydrogens.

2,3-Dimethylpentane is a fully saturated, acyclic, unbranched-in-effect skeleton once you count all seven carbons (five in the pentane chain, two in the methyl branches) with no ring and no double bond to cost any hydrogens: C₇H₁₆, 16 hydrogens – more than any of the others, because it’s the only one with seven carbons and zero rings or double bonds.

Cyclohexane and 2,3-dimethyl-2-butene both land on C₆H₁₂ (12 hydrogens) too – the ring costs cyclohexane exactly what the double bond costs the alkene, so both tie with the dimethylcyclobutane above, well short of the pentane derivative.

With 16 hydrogens against 14 or 12 everywhere else, 2,3-dimethylpentane wins – option C.

Full explanation

Four of these five molecules are built around a carbonyl group, C=O, just wearing different disguises. Acetaldehyde is an aldehyde (a carbonyl with a hydrogen attached), acetone is a ketone (a carbonyl flanked by two carbon groups), acetic acid is a carboxylic acid (a carbonyl paired with a hydroxyl), and methyl acetate is an ester (a carbonyl next to an oxygen that links to another carbon chain). Every one of those functional groups has that double bond to oxygen baked in by definition.

Dimethyl ether breaks the pattern. It’s built as R-O-R′ – two methyl groups joined by a single bond to one oxygen atom, with no carbonyl anywhere in the structure. That single C-O-C bridge is the whole story, which is why option A is the one without a carbon-oxygen double bond.

Full explanation

The standard atmosphere is defined as exactly 101325 Pa, and from there the other common pressure units all check out: 760 mmHg and 760 torr are the same thing under two different names (both essentially measure the height of a mercury column), and since 1 bar = 100000 Pa, 101325 Pa works out to 1.01325 bar, or 1013.25 millibar – which rounds to the “1013 millibar” you’ll recognise from weather forecasts. So options A, B, D and E all check out.

Option C is where the trap sits. Since 1 kPa = 1000 Pa, converting 101325 Pa into kilopascals means dividing by 1000, not 100: 101325 Pa ÷ 1000 = 101.325 kPa. The figure “1013.25” is real – it’s just the millibar (equivalently, hectopascal) value from option B, misapplied to the wrong unit. Mixing up kPa with mbar/hPa this way is an easy slip, because the two units differ by only a factor of ten and the number “1013” is genuinely correct for one of them. In kPa, 1 atm is 101.325 kPa, not 1013.25 kPa, which is why option C is the one that does NOT correspond to 1 atm.

Full explanation

To find the quantity of nitrogen atoms present in 0.7g of N₂ , the given mass must be converted to mole first. Then, using Avogadro’s number, the answer can be calculated.

Molar mass of N₂ = 2 x 14 g/mol = 28 g/mol

Mole of 0.7 g of N₂ =massmolar mass=0.7 g28 g/mol= 0.025 mol

Number of molecules of N₂ = 0.025mole x 6.023 x 10²³ = 0.15 x 10²³ molecules

Since one molecule of N₂ contains 2 nitrogen atoms, Number of nitrogen atoms = 2 x 0.15 x 10²³ = 0.3 x 10²³ = 3 x 10²²

Full explanation

Start with a balanced equation: C + O₂ → CO₂ – one mole of carbon reacts with exactly one mole of oxygen gas to give one mole of carbon dioxide.

Convert both masses to moles before comparing them, since grams can’t be compared directly against a 1:1 mole ratio. Carbon: 9 g ÷ 12 g/mol = 0.75 mol. Oxygen: 36 g ÷ 32 g/mol = 1.125 mol.

Because the equation needs C and O₂ in a 1:1 ratio, whichever one runs out first sets the limit on how much CO₂ can form. Here there’s only 0.75 mol of carbon against 1.125 mol of oxygen, so carbon is the limiting reagent – the reaction can only go as far as that 0.75 mol allows, using up 0.75 mol of O₂ along the way and leaving 1.125 − 0.75 = 0.375 mol of oxygen (12 g) unreacted.

That 0.75 mol of carbon becomes 0.75 mol of CO₂ (the same 1:1 ratio from the equation). CO₂’s molar mass is 12 + 2(16) = 44 g/mol, so the mass produced is 0.75 mol × 44 g/mol = 33 g – option A.

The three “leftover oxygen” options (C, D and E: 9 g, 4 g and 18 g) are all wrong for the same reason – none of them matches the actual 12 g of oxygen genuinely left over once the reaction runs out of carbon.

Full explanation

pH measures concentration on a log scale: [H⁺] = 10^−pH. So the starting solution, at pH 2, has [H⁺] = 10⁻² mol/L, and the target solution, at pH 4, has [H⁺] = 10⁻⁴ mol/L – one hundred times more dilute, since each whole pH unit represents a tenfold change in concentration.

Dilution doesn’t remove or add any H⁺ ions, it only spreads the same amount through more volume, so M₁V₁ = M₂V₂ holds throughout: (10⁻² mol/L)(1 mL) = (10⁻⁴ mol/L)(V₂), which rearranges to V₂ = 10⁻²/10⁻⁴ mL = 100 mL.

That 100 mL is the total volume of the diluted solution, not the water added on top of what’s already there. Since the original 1 mL of acid is still part of that 100 mL, the water actually needed is the difference: 100 mL − 1 mL = 99 mL – option D. It’s an easy trap to stop at the 100 mL figure and reach for a nearby wrong option instead of subtracting the starting volume back out.

Full explanation

Bronsted-Lowry theory defines an acid as a proton (H⁺) donor and a base as a proton acceptor – nothing about hydroxide ions or electrons belongs in that definition, which is exactly where four of these five options go wrong.

Option A describes a base by its ability to donate OH⁻ ions – that’s the Arrhenius definition of a base, not the Bronsted-Lowry one. Options B and C both build their conjugate pair around the wrong ion: a conjugate acid forms when a base picks up an H⁺ (not an OH⁻, as B claims), and a conjugate base forms when an acid gives away an H⁺ (not “acquires an OH⁻”, as C claims) – a conjugate acid-base pair always differs by a single proton, never by a hydroxide ion. Option E describes a substance that donates a pair of electrons, which is the definition of a Lewis base, not an acid – the option mislabels it.

Option D survives all of this: a strong acid is, by definition, one that dissociates almost completely, handing away its proton readily. That means whatever’s left behind – its conjugate base – has very little pull left to grab that proton back, which is exactly what makes something a weak base. So a strong acid genuinely does pair with a weak conjugate base, which is why D is the correct statement.

Full explanation

Start by collapsing the double exponent: raising something to the 1/3 power and then to the 1/2 power is the same as raising it once to their product, (1/3)×(1/2) = 1/6. So (512^1/3)^1/2 = 512^1/6.

Now break 512 into a clean base to work with – since 512 = 2⁹, 512^1/6 = (2⁹)^1/6 = 2^9/6 = 2^3/2, which is far easier to simplify than the sixth root of 512 directly.

A fractional exponent of 3/2 splits neatly into a whole-number part and a leftover half: 2^3/2 = 2¹ × 2^1/2 = 2√2 – option A.

The other four options are the kind of result you get from mismanaging that exponent arithmetic along the way – combining the fractional powers incorrectly, or losing track of which root and which power apply to 512 versus to the simplified base of 2 – rather than reducing the exponents cleanly as above.

Hence, the correct answer is (A).

Full explanation

Work from the inside out. First evaluate f(2): substitute x = 2 into f(x) = log₂(x² + 12), giving f(2) = log₂(4 + 12) = log₂16.

Since 16 is a power of 2 – specifically 2⁴ – log₂16 is asking “what power of 2 gives 16”, and the answer is just that exponent: 4. So f(2) = 4.

The question asks for the reciprocal of that result, not f(2) itself – an easy detail to skim past. The reciprocal of 4 is 1/4, which is option D. (Options B and C, 4 and 2, are what you’d land on if you stopped at f(2) or mis-simplified the logarithm instead of taking that extra inverting step.)

Hence, the correct answer is (D).

Full explanation

Since the ball is put back before the second draw, the bag is identical for both extractions – 3 red and 7 green every time – so the two draws are independent, and the probability of green on a single draw is always 7/10.

For two independent events to both happen, multiply their probabilities: P(green, then green) = 7/10 × 7/10 = 49/100 – option D.

It’s worth seeing where a couple of the other options come from. Option E, 9/100, is what you’d get from (3/10)² – the probability of drawing two red balls instead, an easy question-reading slip. Option B, 42/90, comes from forgetting the replacement altogether and calculating as if the first ball stayed out of the bag: 7/10 × 6/9 = 42/90. Option C, 7/10, is just the single-draw probability, never squared for two draws at all.

Hence, the correct answer is (D).

Full explanation

Look at the numerator: x² is non-negative for every real x, and |4x + 3| is non-negative for every real x (it’s a modulus/absolute value). So their sum, the numerator, is always non-negative (≥ 0) for every real x.

Since the numerator is always non-negative, the sign of the whole fraction is determined by the denominator alone (and the denominator must not be zero, or the fraction is undefined).

So we need 4 − 3x > 0. Solving: −3x > −4, and dividing both sides by −3 (which reverses the inequality): x < 4/3.

So the inequality holds for every real x with x < 4/3, i.e. x ∈ (−∞, 4/3).

Hence, the correct answer is (D).

Full explanation

θ sits between the tangent line at A and the chord AB – a sort of boundary case where the “inscribing” point has slid all the way around to A itself. φ, meanwhile, is a genuine inscribed angle, measured from a separate point D sitting on the far arc and looking back at that same chord AB.

The Tangent-Chord (Alternate Segment) Theorem is exactly the rule connecting these two: the angle between a tangent and a chord at the point of tangency always equals the inscribed angle subtended by that chord from the alternate segment – the arc lying on the other side of the chord from the tangent. That’s precisely the setup described here.

So θ = φ – the two angles are equal, which is option D. None of the other relationships fit this pairing: complementary (summing to 90°) and supplementary (summing to 180°) describe angles that share a straight line or a right angle, and explementary (summing to 360°) describes angles completing a full turn – none of which is what a tangent-chord angle and its alternate inscribed angle actually do; they’re simply equal.

Hence, the correct answer is (D).

Full explanation

The volume of a cylinder only ever needs two measurements — the base radius and the height — because V = πr²h, and both are handed to you directly here: r = 5 cm, h = 7 cm. There’s no missing piece, which rules out option E (“cannot be calculated”) before you even reach for a calculator.

Substituting in: V = π(5 cm)²(7 cm) = π(25 cm²)(7 cm) = 175π cm³.

Hence, the correct answer is (B).

Full explanation

By definition, sin(α) = opposite/hypotenuse. The side opposite α is a, and the hypotenuse is c, so sin(α) = a/c, which rearranges to a = c·sin(α) — option D.

Two of the wrong options can be ruled out on principle alone, without even thinking about which side is which: options A and C both require cos(α) = c/a or sin(α) = c/a. But c is the hypotenuse, always the longest side of a right triangle, so c/a is always greater than 1 — and neither sine nor cosine can ever exceed 1. Those two are impossible before you plug in a single value.

Options B and E fail for a different reason: they pair the wrong side with the wrong function. Cosine relates α to its adjacent side, which is b, not a — so cos(α) = b/c, giving b = c·cos(α), not a = c·cos(α) as option B claims. Option E, a = b·cos(α), makes a similar mix-up: relating a and b validly would go through the tangent (a = b·tan(α)), not the cosine.

Hence, the correct answer is (D).

Full explanation

This question is flawed in the original source material — the source itself states “THIS WAS AN INCORRECT QUESTION. So, none of the given options are correct,” and LOCOMOTIVE is publishing that acknowledgement rather than force-fitting one of the five listed options as if it were right.

Power is the rate at which work is done: P = W/t. Work done by a force is W = F × d, so P = (F × d)/t = F × (d/t) = F × v, since speed v = d/t.

Substituting the given braking force F = 210 N: P = F × v = 210v watts.

Since the boat’s speed v is never given a numerical value in the question, the power cannot be reduced to any single number — it can only be expressed as 210v W. None of the five fixed numerical options (420 W, 105 W, 1050 W, 8.4 W, 210 W) can therefore be correct for every possible v, which is exactly why the source itself withdraws this question.

Full explanation

Boyle’s Law governs exactly this situation – same gas, same temperature, only the volume changing – and it says pressure and volume move in opposite directions so that their product stays fixed: P₁V₁ = P₂V₂.

Starting at P₁ = P, V₁ = V, tripling the volume gives V₂ = 3V, so solving for the new pressure: P₂ = P₁V₁/V₂ = PV/(3V) = P/3 – option D.

That inverse relationship is the whole idea behind Boyle’s Law: squeeze a gas into a smaller space and the same number of molecules collide with the container walls more often, raising pressure; let it expand and those collisions become rarer, dropping pressure by the same factor the volume grew. Since the volume tripled, the pressure has to fall to a third of what it was – not stay unchanged (option B, which would only hold if the gas weren’t actually being compressed or expanded) and not grow (option C, which has the relationship backwards).

Hence, the correct answer is (D).

Full explanation

Power dissipated in a resistor follows P = I²R, so solving for resistance gives R = P/I² = 2922 W / (10 A)² = 2922/100 = 29.22 Ω — option B.

The other four options are all built from the same four digits, 2-9-2-2, just with the decimal point in a different place, which is the tell that they come from a slip in the division rather than a genuinely different method. Option A, 2922 Ω, is what you get if you forget to divide by I² at all and just report the power. Option D, 292.2 Ω, comes from dividing by I (10) instead of I² (100) — forgetting to square the current. Option E, 29 220 Ω, is the power multiplied by the current rather than divided by its square — the inverse of the right operation. Option C, 2.922 Ω, overshoots the correct division by an extra factor of ten, as if dividing by 1000 rather than 100.

Hence, the correct answer is (B).

Full explanation

When a charged particle like an electron enters a magnetic field perpendicularly, it feels the Lorentz force F = evB, always directed perpendicular to its velocity. This force changes the electron’s direction continuously but never its speed, so the electron moves in a circle at constant speed (uniform circular motion).

Equating the magnetic force to the centripetal force: evB = m_ev²/r, giving r = m_ev/(eB) — this confirms option B.

The period is T = circumference/speed = 2πr/v = 2πm_e/(eB) — this confirms option C. Since the motion is uniform circular motion, the angular velocity is constant — this confirms option D. The frequency is f = 1/T = eB/(2πm_e) — this confirms option E.

Option A is the false statement: although the electron’s speed stays constant, its velocity (a vector) is continuously changing direction, so the velocity is not constant.

Hence, the correct answer is (A).

Full explanation

Velocity is how position changes over time, so differentiate x(t) = 4cos(ωt) with respect to t: v(t) = dx/dt = −4ωsin(ωt).

Substitute the given values, ω = 2π rad/s and t* = ½ s: v(½) = −4(2π)sin(2π × ½) = −8πsin(π). Since sin(π) = 0 exactly, the whole expression collapses to zero: v(½) = 0 m/s – option E.

That’s not a coincidence of the numbers – it’s built into how simple harmonic motion works. At t* = ½ s, the particle sits at x = 4cos(π) = −4 m, right at the far extreme of its swing (its maximum displacement in the negative direction). Any oscillating particle has to momentarily stop at each extreme before reversing course, exactly like a pendulum hanging still for an instant at the top of its arc – so zero velocity there is exactly what you’d expect physically, not just what the derivative happens to produce.

Hence, the correct answer is (E).

Full explanation

Option A is false: without friction, no dissipative forces remove energy from the pendulum, so its mechanical energy is conserved and it keeps oscillating indefinitely — it never “tends to come to a stop.”

Option B is true (for small angular displacements, at least, which is the standard idealised treatment): the restoring force is proportional to displacement, giving simple harmonic motion.

Option C is true: friction (air resistance, pivot friction) damps the oscillation, decreasing its amplitude over time.

Option D is true: at each extreme of its swing, the pendulum momentarily stops before swinging back.

Option E is true: the pendulum bob traces a circular arc, determined by the length of the rod/string.

Hence, the correct answer is (A).