IMAT 2023 Answers & Worked Solution

Full explanation

This question tests reading comprehension. For best results, first read the passage to get an overview, then examine the options and locate the relevant information in the text.

Option A Explanation:

A) The June temperature this year is consistent with an observed trend.

The text mentions “a pattern of strengthening global heating” caused by fossil fuel burning, and the June temperature aligns with this observed warming trend. Thus, this option is true.

Option B Explanation:

B) June 1979 was the hottest month to date.

False. The text does not state that June 1979 was the hottest; rather, it indicates that temperatures this June are nearly 1°C above the average levels since 1979.

Option C Explanation:

C) Temperatures in June are not related to the El Niño phenomenon.

False. The text explicitly mentions El Niño as a contributing factor, stating it “typically causes temperatures to spike across the world.”

Option D Explanation:

D) The El Niño phenomenon limits the effects of burning fossil fuels.

False. El Niño adds to the warming effects caused by fossil fuels, giving “a further pulse of heat” rather than limiting it.

Option E Explanation:

E) This year, June will be the hottest month on record since 1979.

False. The text says June is not yet complete and may not set a new record, although it is following a warming trend.

Full explanation

According to the given options, the wrong pair is the option D) Elizabeth Bennet – Little Women.

Elizabeth Bennet is a character from Pride and Prejudice, written by Jane Austen.

The main characters of Little Women (written by Louisa May Alcott) are the March sisters, such as Jo and Meg.

Full explanation

De Bello Gallico is Julius Caesar’s own account of the Gallic Wars — a series of commentaries in which he describes his military campaigns in Gaul. So option A is correct, and each of the other four options simply attaches the title to the wrong artist or the wrong art form.

B) A painting by Eugène Delacroix. Delacroix was a Romantic painter, but De Bello Gallico isn’t one of his works — his best-known painting is Liberty Leading the People.

C) A sculpture by Auguste Rodin. Rodin is famous for sculptures like The Thinker and The Kiss, not for anything called De Bello Gallico.

D) An opera by Richard Wagner. Wagner wrote operas such as The Ring Cycle and Tristan und Isolde — De Bello Gallico is not an opera.

E) A collection of poems on the Gallic war by Horace. Horace’s known works include the Odes and Satires; he did not write a poetry collection about the Gallic War.

Full explanation

In a parliamentary system of government, the President of the Republic typically serves as the Head of State, a largely ceremonial position. Their role in judiciary matters is often symbolic or limited to appointments, depending on the country’s constitution.

The Head of Government is the Prime Minister and holds executive powers and runs the government.

Thus, the correct option is option E.

Full explanation

Track the mature pairs and the newborn pairs separately, month by month.

Start (month 0): 3 mature pairs, plus 1 newborn pair that’s too young to breed yet.

End of month 1: each of the 3 mature pairs produces one new pair, giving 3 new newborn pairs. Meanwhile, last month’s 1 newborn pair has had a month to grow up, so it joins the mature group. That leaves 3 + 1 = 4 mature pairs and 3 newborn pairs.

End of month 2: the 4 mature pairs each produce a new pair (4 new newborns), and last month’s 3 newborn pairs mature. That gives 4 + 3 = 7 mature pairs and 4 newborn pairs.

End of month 3: the 7 mature pairs each produce a new pair (7 new newborns), and last month’s 4 newborn pairs mature. That gives 7 + 4 = 11 mature pairs and 7 newborn pairs.

Total pairs at the end of month 3 = 11 + 7 = 18 pairs. Since each pair is 2 rabbits, that’s 18 × 2 = 36 rabbits.

Thus, the correct option is option B) 36.

Full explanation

Given: half-life of X = 2 years, half-life of Y = 3 years.

To calculate the remaining mass of an element after ‘n’ half-lives, follow this formula:

remaining mass = initial mass × (1/2)ⁿ

Initial ratio X:Y = 8:1. Let initial masses be 8m for X and m for Y.

After 6 years (3 half-lives for X and 2 half-lives for Y):

new mass of X = 8m × (1/2)³ = m

new mass of Y = m × (1/2)² = m/4

Thus, new mass ratio after 6 years = m / (m/4) = 4:1.

Full explanation

Each sandwich has to satisfy all three conditions at once: protein ≥ 20 g, fat < 10 g, and energy ≥ 1,300 kJ. Go through the table and rule out anything that fails even one of them.

Protein ≥ 20 g: Tuna (18 g), Vegetables (9 g) and Ham (19 g) all fall short, so those three are out.

Fat < 10 g: of what’s left, Salmon has 12 g of fat, which is too much, so it’s out as well.

Energy ≥ 1,300 kJ: Turkey only provides 1,210 kJ, so it doesn’t make the cut either.

That leaves exactly two sandwiches meeting all three requirements: Beef (€6.90) and Chicken (€6.80). Since the question asks for the minimum you can spend, pick the cheaper of the two.

Therefore, option A) €6.80 is correct.

Full explanation

To solve this question, we must first identify the passage’s main conclusion. Then, we can eliminate options that weaken this conclusion and compare the remaining choices to find which one most strengthens the argument.

The passage discusses the Copernicus European Earth Observation Programme. It first describes Copernicus’ various functions, then concludes that due to its significant benefits, the program should continue to receive funding. Therefore, the main argument is that Copernicus provides valuable services and deserves ongoing financial support.

Options A and E weaken the argument by suggesting alternative programs or methods could provide similar benefits.

Option B discusses the relative importance of social and scientific advances, which is not directly relevant to the passage’s main argument.

Option D supports the argument but focuses on international cooperation rather than funding.

Option C most effectively strengthens the argument by demonstrating that the Copernicus programme’s financial benefits exceed its costs, making it the correct answer.

Full explanation

To find the conclusion in this passage, let’s first break it down into its key components. The passage starts with the Matthew effect — a belief that students with early academic success tend to make less progress over time compared to their peers. The subsequent statements will help determine if they support this initial premise and lead us to the conclusion.

Research findings are provided as evidence. It is found that:

High achievers in Year 3 made less progress to Year 9 than expected. Students with below-average scores made more progress than high achievers. Compensatory growth (more progress by initially low achievers) was significant in reading and numeracy, especially reading.

The evidence supports the Matthew effect. Therefore, we need to find a conclusion in the options that aligns with this initial premise.

Analysis of Other Options

A) Early promise does not guarantee high achievement in the long-term. Correct. This directly aligns with the study’s finding and the Matthew effect.

B) It is easier to teach brighter students than those who are below average. Incorrect. The passage does not discuss the difficulty of teaching students based on ability.

C) Rates of improvement from a low base will always be more rapid than progress from a higher base. Incorrect. While the study highlights a compensatory growth pattern in this specific dataset, it does not generalize to “always” or all contexts, and it does not mention the rate.

D) Numerical skills are harder to improve than language skills. Incorrect. Although compensatory growth was more significant in reading, the passage does not claim numeracy is harder to improve — just that differences were observed.

E) The ‘Matthew effect’ is the result of low expectations by teachers. Incorrect. The passage does not discuss teacher expectations.

Full explanation

Let’s analyse each reaction first

1. Ethyl alcohol fermentation of four molecules of glucose.

Fermentation is a metabolic process that extends glycolysis to allow continuous ATP production without oxygen. It has two main steps:

glycolysis, which breaks down glucose into pyruvate and generates a net gain of 2 ATP per glucose molecule through substrate-level phosphorylation, and NAD+ regeneration, which restores NAD+ from NADH but produces no ATP. Without NAD+ regeneration, glycolysis would stop. Since each glucose yields 2 ATP, fermenting 4 glucose molecules produces a total of 8 ATP. Although fermentation types like lactic acid and alcohol fermentation differ in end products, the ATP yield remains the same because it is entirely dependent on glycolysis.

2. Lactic acid fermentation of six molecules of glucose

This is also one of the fermentation processes, differing in the end products formed from pyruvate. Thus, this reaction also produce 2 ATP per 1 molecule of glucose and for 6 glucose, it yields 12 ATP molecules.

3. The electron transport chain stage of cellular respiration following the metabolism of a single molecule of glucose through the glycolytic and citric acid cycle stages

The electron transport chain (ETC) is the final stage of cellular respiration, following glycolysis and the citric acid cycle, and is the most efficient catabolic pathway for glucose metabolism. In this aerobic process, oxygen acts as the final electron acceptor, allowing the transfer of electrons through a series of protein complexes embedded in the inner mitochondrial membrane. This transfer drives the production of ATP through oxidative phosphorylation. As a result, the complete oxidation of one glucose molecule typically yields around 30 ATP once you add up all the NADH and FADH₂ handed off by glycolysis and the citric acid cycle — by far the largest total of the four options here.

4. Glycolysis of seven glucose molecules

The net energy yield from glycolysis, per glucose molecule, is 2 ATP plus 2 NADH. Thus, glycolysis of 7 glucose molecules yields 14 ATP molecules.

To rank the reactions in order of the total number of net ATP molecules produced from largest to smallest, 3-4-2-1

Full explanation

Since it is mentioned in the paragraph that DMD is an X-linked recessive genetic disease, and X chromosome is one of the two sex chromosomes, it can be derived that DMD is a sex-linked inherited disease.

Option A Explanation:

Because males have only one X chromosome, presence of one recessive allele is enough to develop the condition, in other words, any male receiving the recessive allele from his mother will express the trait. As a result, far more males than females have X-linked recessive disorders.

Thus, this is statement is wrong.

Option B Explanation:

DMD is a sex-linked inherited disease. Thus, this statement is right.

Option C Explanation:

Since the mutated allele is present on the X chromosome, the spread of the mutated allele is influenced by how quickly the associated X chromosome proliferates within the population. Thus, this statement is right.

Option D Explanation:

Because males have only one X chromosome, presence of one recessive allele is enough to develop the condition, in other words, any male receiving the recessive allele from his mother will express the trait. Thus, this statement is right.

Option E Explanation:

If an X-linked trait is due to a recessive allele, a female will express the phenotype only if she is homozygous for that allele. Thus, this statement is right.

Full explanation

Option A Explanation:

pH range for enzyme Y = 3.9 – 7.2 pH range for enzyme W = 8 – 12.1

There is no overlapping pH range where both enzymes can function together. If the pH is adjusted to suit one enzyme, the other enzyme will not function at all.

Thus, this is the correct answer for the pairs of enzymes listed below cannot function together in the same environment.

Option B Explanation:

pH range for enzyme X = 6.4 – 8.2 pH range for enzyme Y = 3.9 – 7.2

There is an overlapping pH range where both enzyme can function together.

Option C Explanation:

pH range for enzyme W = 8 – 12.1 pH range for enzyme Q = 1.3 – 9.5

There is an overlapping pH range where both enzyme can function together.

Option D Explanation:

pH range for enzyme X = 6.4 – 8.2 pH range for enzyme Z = 4 – 8.5

There is an overlapping pH range where both enzyme can function together.

Option E Explanation:

pH range for enzyme Y = 3.9 – 7.2 pH range for enzyme Z = 4 – 8.5

There is an overlapping pH range where both enzyme can function together.

Full explanation

It is given that the virus has DNA as its primary molecule.

DNA is composed of three main components: a deoxyribose pentose sugar, a phosphate group, and a nitrogenous base. The nitrogenous bases in DNA are either purines (adenine and guanine) or pyrimidines (thymine and cytosine). Importantly, uracil is not found in DNA; it is present only in RNA.

Full explanation

Pancreas produces 2 hormones; insulin and glucagon.

In adrenal gland, adrenal medulla produces epinephrine and norepinephrine and adrenal cortex produce mineralocorticoids, glucocorticoids and sex hormones.

Analysis of the given statements

1. Balancing the amount of calcium in the bone and blood :

The main hormones involved in calcium regulation are parathyroid hormone (PTH), vitamin D (calcitriol), and calcitonin. PTH increases blood calcium levels by stimulating bone resorption, enhancing calcium reabsorption in the kidneys, and activating vitamin D, which promotes calcium absorption in the intestines. Calcitonin, produced by the thyroid gland, lowers blood calcium levels by inhibiting bone resorption. Therefore, the adrenal glands and pancreas do not play a primary role in regulating calcium levels in bone and blood.

2. Accelerating sodium absorption in the renal tubules :

Mineralocorticoids, primarily aldosterone, play a key role in salt and water retention by promoting sodium reabsorption and potassium excretion in the kidneys. Other important hormones involved in regulating salt and water balance include renin, angiotensin I, angiotensin II, and antidiuretic hormone (ADH), which collectively help maintain blood pressure and fluid homeostasis. In contrast, pancreatic hormones do not have a direct role in salt and water regulation.

3. Balancing the glucose level in the blood :

Both pancreatic hormones, insulin and glucagon, are essential for regulating blood glucose levels. Insulin lowers blood glucose by promoting glucose uptake and storage, while glucagon raises it by stimulating glycogen breakdown and gluconeogenesis. Additionally, several adrenal gland hormones, including epinephrine, norepinephrine, and glucocorticoids (such as cortisol), can increase blood glucose levels during stress or fasting by enhancing gluconeogenesis, glycogenolysis, and reducing glucose uptake by tissues.

Thus, hormones secreted by the adrenal gland and pancreas play a role together only in the 3rd event. The correct option is option B) 3 only

Full explanation

Many animals exhibit homeostasis for a range of physical and chemical properties through a control system.

1. Blood glucose concentration is regulated by both negative and positive feedback mechanisms involving hormones such as insulin and glucagon. Insulin lowers blood glucose levels by promoting cellular uptake and storage of glucose, while glucagon raises blood glucose levels by stimulating glycogen breakdown and glucose production in the liver, maintaining glucose homeostasis.

2. Body temperature is regulated through mechanisms like sweating and shivering to maintain a stable temperature inside the body for proper functioning.

3. Water level is also controlled through hormones and thirst mechanism to maintain a stable osmolarity value in the extracellular and intracellular space.

4. Body weight is not a tightly controlled variable by homeostatic mechanisms and is influenced by factors like genetics, diet, metabolism, and lifestyle.

Thus, only the 1,2 and 3 are regulated by homeostasis in the body.

Full explanation

In cellular organelles, organelles without membrane are ribosome, microtubules, centrosomes, centrioles, and nucleolus.

Organelles with single membrane are vacuoles, lysosome, rough ER, smooth ER, golgi body, and peroxisomes.

Organelles with double membrane are nucleus, mitochondria, plastids and chloroplasts (specialized plastids).

Thus, the correct option is option C

Full explanation

If an X-linked trait is due to a recessive allele, a female will express the phenotype only if she is homozygous for that allele. Thus, to pass the disorder to a daughter, both parents must carry at least one copy of the color blindness gene on their X chromosome.

Among the three families given, only Family 3 has both mother and father carrying the colorblindness gene, making it the only family where the daughter can inherit the disorder.

Thus, the correct option is option C.

Full explanation

Option A Explanation:

Having a recessive mutation will not play a role in the process of evolution if it occurs in the body cells because the mutated gene will not be inherited by the offspring and, as a result, it does not contribute to the evolution process.

Option B Explanation:

For a mutation to play a role in the process of evolution, it must be passed through from generation to generation, which means it must occur in the germ cells, not in the body cells.

Option C Explanation:

Having a dominant mutation will not play a role in the process of evolution if it occurs in the body cells because the mutated gene will not be inherited by the offspring and, as a result, it does not contribute to the evolution process.

Option D Explanation:

For a mutation to play a role in the process of evolution, it must be passed through from generation to generation, which means it must occur in the germ cells. Thus, this option is true.

Option E Explanation:

A mutation formed by X-rays will not play a role in the process of evolution if it occurs in the body cells because the mutated gene will not be inherited by the offspring and, as a result, it does not contribute to the evolution process.

Full explanation

In many chemical reactions, there is a transfer of one or more electrons (e-) from one reactant to another. These electron transfers are called oxidation-reduction reactions, or redox reactions for short. In a redox reaction, the loss of electrons from one substance is called oxidation, and the addition of electrons to another substance is known as reduction. Thus, option A) best describes redox reactions in living things.

Full explanation

In the given gene pool, there are 6 A alleles and 4 a alleles.

The frequency of the A allele is:

number of A alleles / total number of alleles in gene pool = 6/10 = 0.6

Thus, the correct option is option B.

Full explanation

The circadian rhythm is the natural, internal process that regulates the sleep-wake cycle and repeats roughly every 24 hours. Key hormones involved include melatonin, produced by the pineal gland, which promotes sleep, and cortisol, which peaks in the morning to promote wakefulness.

Circadian rhythms influence not only sleep but also other physiological processes like hormone release, body temperature, and metabolism.

Option A Explanation:

The amygdala is involved in processing emotions, memory, and fear responses. It does not regulate circadian rhythms.

Option B Explanation:

The corpus callosum is a bundle of nerve fibers that connects the two hemispheres of the brain and facilitates communication between them. It is unrelated to circadian rhythm regulation.

Option C Explanation:

For pineal gland, it plays a crucial role in regulating the circadian rhythm by producing and releasing melatonin, a hormone that signals the body when it is time to sleep. Thus, this option is true.

Option D Explanation:

The thalamus acts as a relay center for sensory information to the cerebral cortex. While it plays a role in sleep and wakefulness, it is not the primary regulator of circadian rhythms.

Option E Explanation:

The hippocampus is primarily involved in memory formation and spatial navigation. It does not regulate circadian rhythms.

Full explanation

We can summarize the complex series of chemical reactions in photosynthesis with this chemical equation:

6CO₂ + 12H₂O + light energy → C₆H₁₂O₆ + 6CO₂ + 6O₂

Water appears on both sides of the equation because 12 molecules are consumed and 6 molecules are newly formed during photosynthesis. We can simplify the equation by indicating only the net consumption of water:

6CO₂ + 6H₂O + energy → C₆H₁₂O₆ + 6O₂

Thus, Option B represents the balanced equation for the overall reaction of photosynthesis.

Full explanation

Immediately after acetylcholine binds to postsynaptic receptors of a muscle fibre, it opens ligand-gated ion channels, cause depolarization and action potential generation.

The action potential propagates along the sarcolemma and into the T- tubules. This causes calcium ions (Ca²⁺) to be released from the Sarcoplasmic reticulum into the sarcoplasm.

Calcium binds to troponin C causing a conformational change in troponin and tropomyosin, exposing myosin-binding sites on actin.

Myosin heads bind to the exposed binding sites on actin, forming cross- bridges.

Then, muscle fiber contracts according to the sliding filament mechanism. Thus, the correct order of the given event would be 2-1-3

Full explanation

64 codons can be made from 3 base and among these 64 codons, 3 codons (UAA, UAG, UGA) are stop codons and do not code for any amino acid.

Percentage of stop codons = (3/64) × 100 = 4.6875%, which rounds to 4.7%.

Thus, the correct answer is option A) 4.7%

Full explanation

In a prokaryotic cell, the DNA is concentrated in a region that is not membrane-enclosed, called the nucleoid. Most genes are carried on a single bacterial chromosome that consists of a circular DNA molecule and associated proteins.

Option A Explanation:

This option is wrong because prokaryotic DNA is not associated with histone proteins and prokaryotes do not carry out either mitosis or meiosis. They undergo a type of reproduction called binary fission.

Option B Explanation:

This option is wrong because prokaryotic DNA is not organized into chromatin fibers.

Option C Explanation:

This option is wrong because prokaryotic genes are carried only on a single chromosome not multiple.

Option D Explanation:

This option accurately describes prokaryotic DNA.

Option E Explanation:

This option is incorrect because prokaryotic DNA is typically continuous, lacking introns, unlike eukaryotic DNA which contains introns within its coding regions.

Full explanation

It is given that the fragment of double-stranded DNA contains 12 phosphates. Each nucleotide is composed of deoxyribose sugar, phosphate group and nitrogenous base. Thus, if there are 12 phosphates in the DNA, there must be 12 deoxyribose sugar. Since it is a double-stranded DNA, there must be 6 base pairs. In double-stranded DNA, the number of purines (adenine and guanine) is always equal to the number of pyrimidines (thymine and cytosine) due to base pairing rules. Adenine pairs with thymine and guanine pairs with cytosine, maintaining a strict 1:1 ratio between purines and pyrimidines. This balance, described by Chargaff’s rules, ensures the stability and uniform width of the DNA double helix.

Each base pair has 1 purine (either A or G) and 1 pyrimidine (either T or C). Since there are 6 base pairs in total, Total purines = 6.

The fragment contains 2 adenines (A), which pair with 2 thymine (T). Each A-T pair contributes 2 hydrogen bonds: and thus, this gives 4 hydrogen bonds. The remaining base pairs are 4 G-C pairs (since 6 base pairs – 2 A-T pairs + 4 G-C pairs). Each G-C pair contributes 3 hydrogen bonds and thus, this gives 12 hydrogen bonds. Total hydrogen bonds = 4 + 12 = 16

Thus, total number of purine bases = 6 total number of deoxyribose sugar = 12 total number of hydrogen bonds = 16

The correct option is option E) 6, 12, 16

Full explanation

As a cell increases in size, its surface area grows at a slower rate compared to its volume because surface area scales with the square of the linear dimension, while volume scales with the cube of the linear dimension. As a result, smaller cells have a larger surface area-to-volume ratio, which facilitates more efficient exchange of materials with their environment, whereas in larger cells, this ratio decreases, making transport of substances less efficient as size increases.

Only the option A) accurately describes the surface area-to-volume ratio and cell growth.

Full explanation

We can think of the Golgi as a warehouse for receiving, sorting, shipping, and even some manufacturing. It consists of stacks of associated, flattened sacs, or cisternae, which are not physically connected to each other, and is especially extensive in cells specialized for secretion.

Functions of the Golgi apparatus:

Products of the ER, such as proteins, are modified and stored and then sent to other destinations. Membrane phospholipids may also be altered in the Golgi. It manufactures some macromolecules and adds molecular identifying tags to the products.

Option A Explanation:

This option is wrong because in neuronal cells, neurotransmitters need to be released, and the Golgi apparatus is specialized to handle the packaging and sorting of these molecules. Thus, the Golgi is an essential organelle in neuronal cells.

Option B Explanation:

This option is incorrect because, although the Golgi apparatus processes lipids, it does not handle lipid molecules entering the cell. Instead, it processes lipids synthesized in the smooth endoplasmic reticulum.

Option C Explanation:

The statement is incorrect because lysosomes are responsible for breaking down macromolecules, damaged organelles, and cellular waste, not for digesting vesicles released from the Golgi apparatus. Proteins processed and packaged by the Golgi are transported in secretory vesicles to the plasma membrane, where they are released into the extracellular space through exocytosis. Lysosomes function in degradation rather than secretion, so they do not play a role in releasing proteins from the cell.

Option D Explanation:

This option is wrong because once proteins are synthesized on ribosomes (in the cytoplasm as free ribosomes or rough ER as bound ribosomes), they are not sent back to the nucleus for “translation verification.” Proteins are modified, sorted, and packaged in the Golgi before being sent to their final destinations.

Option E Explanation:

This option correctly describes the primary function of the Golgi apparatus.

Full explanation

Glycolysis is a ten-step metabolic pathway that breaks down glucose into pyruvate. Isomerase enzymes play a crucial role at specific stages of this process. One key step involves the conversion of glucose-6-phosphate to fructose-6-phosphate by phosphoglucose isomerase. Another important isomerase-catalyzed reaction is the interconversion between dihydroxyacetone phosphate (DHAP) and glyceraldehyde-3-phosphate (G3P), catalyzed by triose phosphate isomerase. These isomerase steps are essential for ensuring that glycolysis proceeds efficiently by rearranging molecules into forms that can continue through subsequent reactions.

Option A Explanation:

This option correctly describes one of two reactions where an isomerase enzyme is used in the glycolysis pathway.

Option B Explanation:

This option is wrong because isomerase enzymes are not the same enzymes as dehydrogenase enzymes. In glycolysis, the key dehydrogenase enzyme is glyceraldehyde-3-phosphate dehydrogenase (G3PDH). This enzyme catalyzes the sixth step of glycolysis, where glyceraldehyde-3-phosphate (G3P) is oxidized and phosphorylated to form 1,3-bisphosphoglycerate (1,3-BPG). During this reaction, NAD+ is reduced to NADH, capturing energy in the form of high-energy electrons. This step is crucial because it links the oxidation of glucose-derived molecules to the generation of NADH, which will later feed electrons into the electron transport chain under aerobic conditions. Thus, dehydrogenase enzymes in glycolysis are essential for energy transfer and the continuation of the metabolic pathway.

Option C Explanation:

This option is wrong because the aldolase enzyme is used in the mentioned reaction instead of an isomerase enzyme. In glycolysis, the aldolase enzyme catalyzes the cleavage of fructose-1,6-bisphosphate into two three-carbon molecules: dihydroxyacetone phosphate (DHAP) and glyceraldehyde-3-phosphate (G3P).

Option D Explanation:

This option is wrong because isomerase enzyme does not take part in the mentioned reaction.

Option E Explanation:

This option is wrong because kinase enzyme would be used for phosphorylation. In glycolysis, kinase enzymes play a crucial role by catalyzing the transfer of phosphate groups from ATP to specific substrates, a process known as phosphorylation. Key kinases involved include hexokinase, which phosphorylates glucose to form glucose-6-phosphate in the first step, and phosphofructokinase-1 (PFK-1), which catalyzes the conversion of fructose-6-phosphate to fructose-1,6-bisphosphate — a major regulatory step. Later, phosphoglycerate kinase and pyruvate kinase facilitate substrate-level phosphorylation steps that generate ATP. Overall, kinase enzymes are essential for both the energy investment and energy payoff phases of glycolysis.

Full explanation

A polynucleotide has a built-in directionality along its sugar-phosphate backbone, running from the 5′ end to the 3′ end, much like a one-way street. The 5′ end is characterized by a phosphate group attached to the 5′ carbon of the sugar, while the 3′ end has a hydroxyl group on the 3′ carbon. This structural arrangement establishes the molecule’s direction. Therefore, to determine the orientation of a polynucleotide, it is necessary and sufficient to identify the positions of the phosphate group and the hydroxyl group.

Thus, the correct option is option C.

Full explanation

The pathway of electron transport

NADH donates electrons to complex I (NADH dehydrogenase), while FADH₂ donates electrons to complex II(succinate dehydrogenase).

CoQ shuttles electrons from complexes I and II to complex III.

Complex III passes electrons to another mobile carrier, cytochrome c. cytochrome c carries electrons from complex III to complex IV The final step in the chain, complex IV transfers electrons to oxygen, the terminal electron acceptor.

Oxygen combines with electrons and protons (H⁺) to form water.

As electrons move through complexes I, III, and IV, protons (H⁺) are pumped from the mitochondrial matrix into the intermembrane space.

This creates a proton gradient (electrochemical gradient) across the inner mitochondrial membrane which is used by ATP synthase to catalyze the conversion of ADP to ATP.

Analysis of the given statements

Statement 1 is wrong because Complex I of the electron transport chain transfers electrons from NADH to coenzyme Q, not from FADH₂ Statement 2 correctly describes a step in oxidative phosphorylation Statement 3 is wrong because oxygen accepts electrons from complex IV and there is no oxygen in complex III.

Statement 4 is wrong because complex IV receives electrons from complex III, not from NADH.

Thus, the correct option is option C) 2

Full explanation

Mendel deduced two fundamental principles of heredity, now called the law of segregation and the law of independent assortment.

4 concepts of Mendel’s model:

Alternative versions of genes account for variations in inherited characters. For each character, an organism inherits two copies (that is, two alleles) of a gene, one from each parent. If the two alleles at a locus differ, then one, the dominant allele, determines the organism’s appearance; the other, the recessive allele, has no noticeable effect on the organism’s appearance. The two alleles for a heritable character segregate (separate from each other) during gamete formation and end up in different gametes (law of segregation).

Law of independent assortment:

Two or more genes assort independently — that is, each pair of alleles segregates independently of any other pair of alleles — during gamete formation.

These are the main inheritance patterns that Mendel observed and developed through his experiments.

Among the 5 points mentioned in the question, points 1 to 4 accurately reflect Mendel’s laws. The last point, “Individuals with heritable traits more suited to the environment will have an increased chance of survival”, reflects the concept of natural selection from Darwin’s theory of evolution, not Mendel’s laws of inheritance.

Thus, the correct option is option A) 1, 2, 3 and 4.

Full explanation

According to the given information,

mass number (A) = 2x+2, number of protons (Z) = x

As the ion has a positive charge of 2+, there are two less electrons than protons:

Thus, number of electrons = x – 2

Full explanation

This is a question about the ideal gas law at fixed (constant) volume, so Gay-Lussac’s Law applies: P₁/T₁ = P₂/T₂.

T₁ = 27.0 + 273 = 300 K, with P₁ = P Pa. T₂ = 327.0 + 273 = 600 K, with P₂ = ? (absolute zero is given as −273.0°C, consistent with the standard Kelvin conversion used here).

P₂ = P₁ × T₂/T₁ = P × 600/300 = 2P Pa.

Hence, the correct answer is (A).

Full explanation

To solve this question, we have to compare the acidity of each solution and the most acidic solution will have the lowest pH and the least acidic solution will have the highest pH.

CH₃COOH is a weak acid and it will dissociate into less than 0.1 mole of hydrogen ion.

NaCl is a neutral salt and thus, pH would be around 7.

H₂SO₄ is a strong diprotic acid and it will dissociate into 0.2 moles of hydrogen ion. This solution seems to be the most acidic one among others and thus will have the lowest pH.

Ba(OH)₂ is a strong base and thus, it will have the highest pH among others.

HNO₃ is a monoprotic strong acid and it will dissociate into 0.1 mole of hydrogen ion.

Thus, in comparison, solutions in order of increasing pH would be H₂SO₄, HNO₃, CH₃COOH, NaCl, Ba(OH)₂. In number, it would be 3, 5, 1, 2, 4.

Full explanation

Structural isomers (or constitutional isomers) are compounds that have the same molecular formula but different structural arrangements of atoms (in the amounts of branching in their chains, or in the positions or the nature of functional groups).

Thus, we have to find the molecular formula for each compound first.

In the compound number 1, there are 6 carbon atoms, 12 hydrogen atoms and 2 oxygen atoms. Thus, the molecular formula is C₆H₁₂O₂.

In the compound number 2, there are 6 carbon atoms, 12 hydrogen atoms and 2 oxygen atoms. Thus, the molecular formula is C₆H₁₂O₂.

In the compound number 3, there are 6 carbon atoms, 12 hydrogen atoms and 2 oxygen atoms. Thus, the molecular formula is C₆H₁₂O₂.

The molecular formula of hexanoic acid is CH₃(CH₂)₄COOH, which can be converted to C₆H₁₂O₂.

It can be seen that all 3 compounds have the same molecular formula with hexanoic acid but different structural arrangements of atoms. Thus, all 3 compounds are the structural isomers of hexanoic acid.

Full explanation

From Oxidation-Reduction point of view,

Since the oxidation states of sulfur and nitrogen do not change, no redox reaction occurs. Thus, option D and E can be excluded.

For HNO₃ to be a catalyst, it must stay unchanged at the end of the process. Thus, option C can be excluded.

From acid-base point of view,

Since H₂SO₄ transfer a proton to HNO₃, H₂SO₄ is an acid and HNO₃ is a base. Thus, nitric acid is considered as a base in this equation.

Full explanation

At first, we can exclude the molecules that do not have linear structures.

In nitrogen dioxide (NO₂), the nitrogen atom is bonded to one oxygen atom through a double bond and to another oxygen atom through a single bond. Additionally, there is a lone unpaired electron (a radical) on the nitrogen atom. This arrangement results in three electron domains (two bonding regions and one unpaired electron) around the nitrogen. According to VSEPR theory, the electron domain geometry is trigonal planar. However, due to the presence of the lone unpaired electron, the molecular geometry is bent and the molecule is not perfectly planar.

In sulfur trioxide, sulfur is bonded to two oxygen atoms via double bonds and one oxygen atom via a single bond. Since there are 3 electron domains on the sulfur atom, its electron domain geometry is trigonal planar.

In sulfur dioxide, sulfur is bonded to two oxygen atoms via double bonds and there is one lone pair on sulfur. Since there are 3 electron domains on the sulfur atom, its electron domain geometry is trigonal planar.

Thus, we can exclude these 3 options.

If we compare carbon dioxide and silicon dioxide, both molecules have a linear shape. However, silicon dioxide is insoluble in water, so it cannot react with water to form an acidic solution. Silicon dioxide (SiO₂) is insoluble in water because it has a giant covalent network structure, where each silicon atom is strongly bonded to four oxygen atoms in a three-dimensional lattice. These covalent bonds are extremely strong and require a large amount of energy to break. Water, being a polar solvent, dissolves substances by surrounding and separating individual ions or molecules, but it cannot disrupt the extensive covalent bonds in SiO₂. As a result, silicon dioxide remains insoluble in water.

Thus, the only correct option is A) Carbon dioxide.

Full explanation

Option A Explanation:

Ice have greater volume than liquid water due to maximum hydrogen bonding which keeps the molecules at a fixed distance and further apart. Thus, this option is true.

Option B Explanation:

Ice have greater volume than liquid water due to maximum hydrogen bonding which keeps the molecules at a fixed distance. The particles in ice state has less kinetic energy than those in the liquid state. Thus, this option is false.

Option C Explanation:

In fact, ice has a greater volume than liquid water because the water molecules in ice are arranged in a rigid, open hexagonal lattice held together by hydrogen bonds. This structure keeps the molecules further apart compared to the more disordered, closer-packed arrangement in liquid water. As a result, ice is less dense and occupies more volume than the same mass of liquid water.

Option D Explanation:

While it is true that liquid water molecules have more kinetic energy than those in ice (because temperature and molecular motion are higher in liquids), kinetic energy does not directly determine volume. The volume is smaller in liquid water because the increased movement allows the molecules to break some hydrogen bonds and pack closer together, reducing the volume compared to the rigid open structure of ice.

Option E Explanation:

Liquid water and ice do not have the same volume. Ice occupies more volume than the same mass of liquid water because of its expanded hydrogen-bonded structure. This is why ice is less dense than water, causing it to float, not because their volumes are equal. Floating occurs due to the lower density of ice, not due to equal volumes.

Full explanation

Given : It is a gaseous exothermic reaction and the Kc value is very small.

From its very small Kc value, it can be deduced that there are proportionately less products with respect to reactants, so the equilibrium mixture lies to the left and there are more moles on the left-hand side of the reaction. This excludes the option A and option C.

Addition of a catalyst effects only the rate of the reaction by increasing its speed.. It does not effect the yield. This excludes the option D.

Since the reaction is an exothermic reaction, if the temperature is decreased, the reaction will shift to the right and more products will be formed. This increases the Kc value. Thus, option B is true.

For option E, we cannot conclude anything without the information about the mole ratios of the reactants and products.

Full explanation

Paracetamol is an aromatic compound with hydroxyl group and amide group as functional groups. Hydroxyl group can be found on the provided structure as an OH group attached to the benzene ring and amide group as -CONH group attached to the benzene ring. Thus, the correct option is option A.

Full explanation

Both elements and molecules are under the category of pure substances.

An element is composed of only one type of atoms. Elements cannot be broken down into simpler substances via a chemical reaction.

A molecule is a group of two or more atoms (either the same element or different elements) held together by chemical bonds.

In the five given substances, N₂, O₂, and Ar are elements because they consist of only one type of atom. N₂, O₂, CO₂, and H₂O are molecules because they are a group of two or more atoms held together by chemical bonds.

Thus, 3 of given substances are elements and 4 of given substances are molecules. The correct option is option A.

Full explanation

Ionization energy: the energy required to remove one mole of electrons from one mole of gaseous atoms in their ground state.

Ionization energy trend: increase across a period and decrease down a group.

Alkali metals such as Sodium, Potassium and Lithium tend to have lower ionization energy because they are group 1 elements and they have only 1 electron on the highest principal energy level and it does not need much energy to remove that electron. Thus, we can exclude option A, C and E.

Noble gases such as Neon and Argon have the fully filled electrons shells and thus, a lot of energy is required to remove an electron from the stable octet. In comparison, the removed electrons are much further from nucleus in Argon than in Neon. Thus, attraction between the removed electrons and nucleus is stronger in Neon and has higher ionization energy.

Therefore, among the given elements, Neon has the highest first ionization energy.

Full explanation

Option A Explanation:

In PF₃ molecule, molecular geometry is trigonal pyramidal shape and dipoles do not cancel out. Thus, it has overall dipole moment.

Option B Explanation:

In BeF₂ molecule, molecular geometry is linear shape and dipoles cancel out. Thus, it does not have an overall dipole moment.

Option C Explanation:

In CF₄ molecule, molecular geometry is tetrahedral shape and dipoles cancel out. Thus, it does not have an overall dipole moment.

Option D Explanation:

In SF₆ molecule, molecular geometry is octahedral shape and dipoles cancel out. Thus, it does not have an overall dipole moment.

Option E Explanation:

In PF₅ molecule, molecular geometry is trigonal bipyramidal geometry shape and dipoles cancel out. Thus, it does not have an overall dipole moment.

Full explanation

TiO₂ + 2Cl₂ + 2C → TiCl₄ + 2CO

In this reaction, Cl is reduced because its oxidation state decreases from 0 to -1.

C is oxidized because its oxidation state increases from 0 to +2.

In a redox equation, the substance that is reduced is the oxidizing agent, the substance that is oxidized is the reducing agent.

Thus, in this reaction, C is the reducing agent.

Full explanation

Iron is made by reduction of iron oxide using carbon monoxide: Fe₂O₃ + 3CO → 2Fe + 3CO₂. 50 g of iron is made in a reaction from 80 g of iron oxide.

To find the percentage yield, first find the theoretical yield of iron. M(Fe₂O₃) = 2(56) + 3(16) = 112 + 48 = 160 g/mol.

n(Fe₂O₃) = m/M = 80 g / 160 g/mol = 0.5 mol.

From the balanced equation, 1 mole of Fe₂O₃ yields 2 moles of Fe, so 0.5 mol of Fe₂O₃ yields 1 mol of Fe, which has a mass of 1 × 56 = 56 g. This is the theoretical yield.

Percentage yield = (actual yield / theoretical yield) × 100 = (50/56) × 100.

Hence, the correct answer is (A).

Full explanation

A diprotic acid is an acid that can donate two protons per molecule when dissolved in water. These protons are usually attached to highly electronegative atoms (e.g. oxygen).

Option A is oxalic acid (ethanedioic acid), HOOC–COOH. It has 2 carboxyl groups, each of which contains a dissociable hydrogen atom, and it is a weak acid overall. This makes it a weak, diprotic acid — this option is correct.

Option B is sulfuric acid, H₂SO₄. Although it has 2 dissociable protons, it is a strong acid, not a weak one, so this option is false.

Option C is formic acid (methanoic acid), HCOOH. It has only one carboxyl group and therefore only one dissociable proton, so it is monoprotic, not diprotic — this option is false.

Option D is glyoxal (ethanedial), OHC–CHO. Its hydrogen atoms are bonded directly to carbon, not to a highly electronegative atom, so they cannot dissociate as protons at all — this option is false.

Option E is ethylene glycol (ethane-1,2-diol), HO–CH₂–CH₂–OH. It has 2 hydroxyl groups but is an alcohol, not an acid — this option is false.

Hence, the correct answer is (A).

Full explanation

First simplify f(x): f(x) = 2ln(x) − 2ln(x − 1) = 2[ln(x) − ln(x − 1)] = 2ln(x/(x − 1)).

Let y = f(x), so y = 2ln(x/(x − 1)), giving y/2 = ln(x/(x − 1)). Exponentiating both sides (base e): e^y/2 = x/(x − 1).

Solve for x: e^y/2x − e^y/2 = x, so e^y/2x − x = e^y/2, so x(e^y/2 − 1) = e^y/2, giving x = e^y/2/(e^y/2 − 1).

So f⁻¹(y) = e^y/2/(e^y/2 − 1). To avoid division by zero we need e^y/2 − 1 ≠ 0, i.e. e^y/2 ≠ 1, i.e. y ≠ 0. Since f(x) is defined for x > 1, the range of f (and hence the domain of f⁻¹) is further restricted to values where e^y/2 > 1, i.e. y > 0.

Hence, the correct answer is (B).

Full explanation

First solve the corresponding quadratic equation 2x² − 6x + 5 = 0 using the quadratic formula, with a = 2, b = −6, c = 5: x = [−(−6) ± √((−6)² − 4(2)(5))] / [2(2)] = [6 ± √(36 − 40)] / 4 = [6 ± √(−4)] / 4.

Since the discriminant is negative, the roots are complex, meaning the quadratic 2x² − 6x + 5 never crosses the x-axis. Since its leading coefficient (2) is positive, the parabola opens upward and so the expression is positive for every real x.

Therefore the inequality 2x² − 6x + 5 > 0 holds for all real numbers, so the solution set is ℝ.

Hence, the correct answer is (A).

Full explanation

Let the initial quantities be x kg of sugar and 5x kg of flour (ratio 1:5). After adding 1 kg sugar and 2 kg flour: (x + 1)/(5x + 2) = 2/5.

Cross-multiplying: 5(x + 1) = 2(5x + 2), so 5x + 5 = 10x + 4, so 5x = 1, giving x = 1/5.

So the initial quantities are 1/5 kg sugar and 1 kg flour (since 5x = 1). After the first addition: sugar = 1/5 + 1 = 6/5 kg, flour = 1 + 2 = 3 kg (consistent with ratio 2:5, since (6/5)/3 = 2/5, confirming x is correct).

After the second addition of 1 kg sugar and 2 kg flour: new sugar = 1/5 + 1 + 1 = 11/5 kg, new flour = 1 + 2 + 2 = 5 kg.

New ratio = (11/5) : 5 = 11 : 25.

Hence, the correct answer is (E).

Full explanation

The prime numbers from 1 to 6 are 2, 3 and 5, whose squares are 4, 9 and 25 respectively. There are 6 × 6 = 36 equally likely outcomes when rolling two dice.

Product = 4: possible outcomes are (1,4), (2,2), (4,1) — 3 outcomes.

Product = 9: possible outcome is (3,3) — 1 outcome.

Product = 25: possible outcome is (5,5) — 1 outcome.

Total favourable outcomes = 3 + 1 + 1 = 5, so P(product is the square of a prime) = 5/36.

Hence, the correct answer is (B).

Full explanation

Write 1/16 as (±½)⁴, so sin⁴[(x + 90°)/10] = (±½)⁴. Taking the fourth root of both sides: sin[(x + 90°)/10] = ±½.

Within one cycle 0° to 360°, sinθ = +½ at θ = 30°, 150°, and sinθ = −½ at θ = 210°, 330°.

So (x + 90°)/10 = 30°, 150°, 210° or 330°, giving x = 10θ − 90°: for θ=30°, x=210°; for θ=150°, x=1410°; for θ=210°, x=2010°; for θ=330°, x=3210°.

Only x = 210° lies within the required range 0° ≤ x ≤ 360°, so there is exactly 1 solution.

Hence, the correct answer is (E).

Full explanation

First inequality: 100 − 99x ≤ 98 − 97x ⇒ 100 − 98 ≤ 99x − 97x ⇒ 2 ≤ 2x ⇒ x ≥ 1.

Second inequality: 96 + 95x > 94 + 93x ⇒ 95x − 93x > 94 − 96 ⇒ 2x > −2 ⇒ x > −1.

The values satisfying both simultaneously are the intersection of x ≥ 1 and x > −1, which is simply x ≥ 1.

Hence, the correct answer is (C).

Full explanation

Complete the square: x² − 10x = (x − 5)² − 25, and y² + 12y = (y + 6)² − 36.

Substituting: (x − 5)² − 25 + (y + 6)² − 36 + 57 = 0, so (x − 5)² + (y + 6)² = 4 = 2².

So the circle has centre (5, −6) and radius r = 2. The distance from the centre to the x-axis is 6 and to the y-axis is 5; the minimum distance from the circle itself to either axis is the smaller of these distances minus the radius: 5 − 2 = 3.

Hence, the correct answer is (E).

Full explanation

Rewrite every term as a power of 2: 16ₓ = (2⁴)ₓ = 2⁴ₓ; 8ₓ = (2³)ₓ = 2³ₓ; 4ₓ = (2²)ₓ = 2²ₓ; 2ₓ = 2ₓ.

Substitute: √[(2⁴ₓ + 2³ₓ)/(2²ₓ + 2ₓ)] = √[2³ₓ(2ₓ + 1) / (2ₓ(2ₓ + 1))] = √(2³ₓ/2ₓ) = √(2²ₓ) = 2ₓ.

Hence, the correct answer is (A).

Full explanation

For an elastic collision where mass m₁ = m moving at u₁ = v strikes a stationary mass m₂ = 2m (u₂ = 0), the standard 1-D elastic collision formulas give:

v_A = [(m₁ − m₂)/(m₁ + m₂)]u₁ + [2m₂/(m₁ + m₂)]u₂ = [(m − 2m)/(3m)]v + 0 = (−1/3)v.

The negative sign shows A rebounds in the opposite direction; since only the speed (magnitude) is asked, v_A = ⅓v.

v_B = [(m₂ − m₁)/(m₁ + m₂)]u₂ + [2m₁/(m₁ + m₂)]u₁ = 0 + [2m/(3m)]v = (2/3)v.

Hence, the correct answer is (A).

Full explanation

Since the gas first expands isothermally, its temperature is unchanged by that stage, so T₁ = 25°C = 298 K when the piston is fixed.

With the piston now fixed, the volume is constant, so the subsequent cooling follows Gay-Lussac’s Law: pressure is directly proportional to absolute temperature at constant volume, i.e. P₁/P₂ = T₁/T₂.

Since the final pressure is half the initial pressure (P₂ = P₁/2): T₂ = T₁ × (P₂/P₁) = 298 × ½ = 149 K.

Converting back to Celsius: T₂ = 149 − 273 = −124°C.

Hence, the correct answer is (B).

Full explanation

By calorimetry, heat lost by the water = heat gained by the ice. As the water cools from T₁ to T₂, it loses Q_water = Mc(T₁ − T₂).

The ice first gains heat to melt (mL_f) and then gains heat to warm the resulting meltwater from 0°C up to T₂: Q_ice = mL_f + mc(T₂ − 0) = mL_f + mcT₂.

Setting heat lost equal to heat gained: mL_f + mcT₂ = Mc(T₁ − T₂), so m(L_f + cT₂) = Mc(T₁ − T₂), giving m = Mc(T₁ − T₂) / (L_f + cT₂).

Hence, the correct answer is (A).

Full explanation

The straight-line displacement (using the Pythagorean theorem, since east and south are perpendicular) is √(6² + 8²) = √(36 + 64) = √100 = 10 km.

The trip takes 15 minutes = 15/60 hours = 0.25 hours.

Average velocity = displacement / time = 10 km / 0.25 h = 40 km/h.

Hence, the correct answer is (C).

Full explanation

Because the spheres are perfectly insulating, no charge can flow between them even while they are touching — charge only redistributes across contacting conductors, not insulators.

So the charge on each sphere remains exactly as it was originally: the sphere of radius R₁ keeps its original charge Q₁.

Hence, the correct answer is (B).