IMAT 2017 Answers & Worked Solution

Full explanation

Let N stand for how many chocolates of each colour the tin started with – it’s the same number for red, blue, yellow and green, since the tin has equal amounts of each.

Track what one full round of passing removes. John takes 3 red. Peter takes one of each colour (1 red, 1 green, 1 yellow, 1 blue). Jane takes 1 yellow. And the tin’s owner takes 2 green. Add that up and a single round removes 4 red, 2 yellow, 1 blue and 3 green.

After six rounds, six times those amounts are gone: 24 red, 12 yellow, 6 blue, 18 green. So what’s left in the tin is (N − 24) red, (N − 12) yellow, (N − 6) blue and (N − 18) green – a grand total of 4N − 60 chocolates remaining.

We’re told half of what’s left is blue, so the blue amount has to equal half that total:

N − 6 = (4N − 60) / 2 = 2N − 30

Rearranging: 30 − 6 = 2N − N, so N = 24.

The tin started with 24 chocolates of each colour, so 96 in total (4 × 24) – matching option D. As a check: with N = 24, the red runs out exactly (24 − 24 = 0), leaving 12 yellow, 18 blue and 6 green – 36 chocolates in total – and 18 is indeed exactly half of 36, just as the question says.

Full explanation

Option A is the view we will see from the right side of the frame.

Option B is the view we will see from the top part of the frame.

Option C is the view we will see from the bottom part of the frame.

Option D is the view we will see from the left side of the frame.

Option E is NOT a possible side view of this part of the aluminium window frame.

Full explanation

Work time : 8am – 5:15pm

Sheelagh lives in London.

There are headquarters in 7 countries :

Jakarta (+8), Nairobi (+3), Prague (+1), Ottawa (-5), Moscow (+3), Canberra (+10) and Hong Kong (+8)

Sheelagh sent an email at 3pm.

Email will be read at the following times according to time zone.

Jakarta – 8am (12am – next day – London time)

Nairobi – 8am (5am – next day – London time)

Prague – 4pm (3pm London time)

Ottawa – 10am (3pm London time)

Moscow – 8am (5am London time)

Canberra – 8am (10pm London time)

Hong Kong – 8am (12am – next day – London time)

Thus, the longest possible interval would be 14 hour (headquarters in Nairobi and Moscow)

Full explanation

Each parcel is charged separately according to how many items it holds, so splitting 7 items across more than one parcel can beat the price of one big parcel — but every extra parcel also means paying its own charge again, so it’s only worth checking splits into two parcels (splitting into three or more just adds further charges on top of bands that are already the cheapest per item). The four ways to split 7 items between two parcels are:

• 6 + 1 items: £3.30 + 55p = £3.85
• 5 + 2 items: £1.60 + 70p = £2.30
• 4 + 3 items: £1.30 + 95p = £2.25
• Any split using more than two parcels (e.g. 3 + 2 + 2, or five 1-item parcels) always costs more, since it repeats the flat per-parcel charge extra times without reaching the cheaper 4-, 5- or 6-item bands.

The cheapest option is the 4 + 3 split, at £1.30 + 95p = £2.25.

Full explanation

stand at the doorway,

– square wardrobe on the right side.

– Bed – also on the right side and occupy more than half of the length of the room.

– Desk on the left side

We can exclude option B, C and E as the bed is on the left side.

In option D, the square-shaped desk is on the left side instead of right. Therefore, we can exclude this option.

Thus, the option that gives the correct view of Alex’s bedroom is option A.

Full explanation

For the given 2 x 2 square grid, 3 rows and 3 columns that each contain 2 matchsticks are required. Total – 12 matchsticks are used.

For a 1×1 square grid, 2 rows and 2 columns that each contain 1 matchstick are required. Total – 4 matchsticks If we repeat that pattern, for a 10×10 square grid, 11 rows and 11 columns that each contain 10 matchsticks are required. Total – 220 matchsticks (110 +110)

Full explanation

The passage makes two important points:

• Traditional cigarettes are clearly dangerous because cigarette smoke contains many hazardous compounds.
• E-cigarettes may be less harmful in some respects, because they don’t produce cigarette smoke, and they may help some people quit smoking.
• However, nicotine itself has dangers, and we don’t yet fully understand the long-term effects of using nicotine through e-cigarettes.

So the passage does not conclude that e-cigarettes are as harmful as traditional cigarettes. Instead, it warns us that we cannot assume e-cigarettes are completely safe.

Analysis of the options

Option A : Not mentioned at all about that information.

Option B : Implied possibly, but it’s not the conclusion drawn by the passage.

Option C : True, but this is background information, not the conclusion.

Option D : The passage never says this. In fact, it acknowledges that cigarette smoke contains many hazardous compounds, implying an important difference.

Option E : This combines the passage’s main reasoning: e-cigarettes may be useful for quitting, but the long-term risks of nicotine use through them are still uncertain.

Full explanation

The passage acknowledges the environmental damage caused by palm oil. But, it also points out that some environmental groups warn alternative oils could be worse, requiring even more land.

This leads to the main conclusion: even if palm oil is banned, switching to alternatives could still cause serious environmental harm.

Option A : This is the correct conclusion that can be drawn from the passage.

Option B : This is a possible consequence, but it’s not stated or concluded in the passage.

Option C : Not mentioned at all. The passage focuses on global awareness, not regional understanding.

Option D : The passage says they often are, but it doesn’t say they must be or that it’s for profit reasons.

Option E : Not mentioned. The focus is on environmental impact, not business incentives.

Full explanation

This is a distance-time graph, so time runs along the bottom and distance from Ardale runs up the side. Build up David’s whole trip in stages and see what shape it traces.

He leaves Ardale at 11:00 and runs for 1 hour at 6 km/h, covering 6 km – so he’s at the 6 km mark by 12:00. He rests 20 minutes (still at 6 km, until 12:20), then covers what’s left of the 16 km to Banby – that’s 10 km, not 6 – at 10 km/h, which takes 1 hour. He reaches Banby (16 km) at 13:20.

He chats there for 20 minutes, until 13:40, then cycles the 8 km on to Carston at 16 km/h – that leg takes 30 minutes, so he arrives at Carston (24 km from Ardale) at 14:10.

He’s told to leave Carston at 15:00, so he’s stopped there from 14:10 to 15:00 – 50 minutes. Then he cycles the whole 24 km back to Ardale, arriving at 15:50 – another 50 minutes, bringing him back down to 0 km.

So the graph needs: a rising segment (0–6 km, slope 6 km/h), a flat 20-minute rest, a second rising segment that’s steeper (6–16 km, slope 10 km/h), a second flat 20-minute stretch, a third rising segment steeper still (16–24 km, slope 16 km/h), a much longer flat stretch (50 minutes at Carston), and then a steep drop straight back down to 0 over the final 50 minutes.

That third flat stretch is the giveaway: it’s roughly two and a half times as long as each of the first two rests, not equal to them – so we can rule out any graph that draws all three rests the same length. And the return trip has to end with a drop, not a flat line at the top – so a graph that just stops at Carston is out too. Of the two graphs left, the one where the second rising segment is visibly steeper than the first (matching 10 km/h being faster than 6 km/h) is the right one.

Thus, the correct option is option A.

Full explanation

The passage begins by saying comparison websites claim to save users time and money. Then, it presents a single negative example of one user who received no useful results and was spammed afterwards. Based on this one case, the passage questions the wisdom of using such sites in general.

This is a classic flaw in reasoning: drawing a broad conclusion based on an isolated example.

Option Analysis Option A : The passage never says this or even implies it.

Option B : The argument is about the user’s experience, not an attack on a company.

Option C : Actually, it questions this claim rather than assumes it.

Option D : No such assumption is made.

Option E : This is the correct answer.

Full explanation

The argument defends trawling, claiming it’s not as damaging as environmentalists say, and can even benefit marine life, especially in shallow, sandy areas. To weaken this argument, you need a statement that shows trawling is actually harmful, particularly in a way that contradicts the supposed benefits.

Analysis of the given options Option A : Strengthens the argument.

Option B : Irrelevant to the ecological impact being debated.

Option C : A concern for fishermen, not marine ecosystems.

Option D : Strengthens the argument, not weakens it.

Option E : This is the correct answer.

Full explanation

The argument says it’s right that the captain has been removed so that the team can pull together and have a better chance of winning. For this conclusion to make sense, it depends on the assumption that:

His actions were harming team unity and morale.

Without this assumption, there would be no reason to think that removing him would help the team perform better.

Analysis of the options Option A : This is the correct answer.

Option B : Irrelevant. The argument is about removing him now, not about his initial appointment.

Option C : Too strong. The argument says it will improve their chances, not guarantee a win.

Option D : Opposite of the argument’s intent — it’s trying to help the team win.

Option E : Irrelevant. The focus is on the captain’s impact on the team, not media ethics.

Full explanation

Given :

Luke walks 1 km in 12 minutes, giving him a walking speed of (1km)/(0.2 hrs) = 5km/hr. The puppy’s movement involves repeated cycles of running ahead 100 meters and returning to Luke, who walks 50 meters per cycle.

Key steps:

1. Cycle analysis: Each cycle consists of:

– Puppy running 100 meters ahead.

– Puppy returning to Luke, who has walked 50 meters.

– Total puppy distance per cycle:

100 m+50 m=150 m

2. Total cycles: Luke walks 1 km (1000 meters) at 50 meters per cycle: (1000m)/(50 m/cycle) = 20 cycles

3. Puppy’s total distance: 20 cycles×150 m/cycle=3000 m=3 km

4. Average speed calculation: Puppy’s speed: (3 km)/(0.2 hours) = 15 km/h

The puppy’s average running speed is 15 km/h.

Full explanation

The main argument claims that: Media attention has increased interest in forensic science. This has led to more courses and more students. But not more jobs, so…Students who study forensics will face fierce competition for limited, unpleasant work.

To weaken this argument, we need to challenge the idea that all or most students are aiming for, and competing for, the same limited forensic science jobs.

Analysis of the options Option A : Supports the argument — it shows a tough job market.

Option B : If many students go into other careers, then: The job competition is not as fierce as claimed. The conclusion that studying forensics leads to a tough job market becomes less convincing. Therefore, this is a correct option.

Option C : Supports the argument — fewer jobs, more competition.

Option D : Supports the argument — more students trained, same number of jobs.

Option E : Irrelevant to the point about job availability and competition.

Full explanation

Calculations for each friend:

– Harry (85kg): Walks fast for 30 minutes + walks slow for 30 minutes

– Walking fast: 310 calories/hour × 0.5 hours = 155 calories

– Walking slow: 200 calories/hour × 0.5 hours = 100 calories

– Total: 255 calories

– Holly (60kg): Runs fast for 20 minutes + walks slow for 10 minutes

– Running fast: 510 calories/hour × 0.33 hours = 170 calories

– Walking slow: 150 calories/hour × 0.17 hours = 25 calories

– Total: 195 calories

– Jessie (75kg): Runs fast for 10 minutes + runs slow for 20 minutes

– Running fast: 540 calories/hour × 0.17 hours = 90 calories

– Running slow: 420 calories/hour × 0.33 hours = 140 calories

– Total: 230 calories

– Josie (100kg): Walks fast for 30 minutes + walks slow for 30 minutes

– Walking fast: 350 calories/hour × 0.5 hours = 175 calories

– Walking slow: 240 calories/hour × 0.5 hours = 120 calories

– Total: 295 calories

– Paul (60kg): Runs slow for 20 minutes + walks fast for 20 minutes

– Running slow: 360 calories/hour × 0.33 hours = 120 calories

– Walking fast: 210 calories/hour × 0.33 hours = 70 calories

– Total: 190 calories

Josie burns the most calories with 295 calories total.

The answer is E. Josie.

Full explanation

The argument concludes that buying additional insurance is unnecessary because: Victims of credit card fraud are reimbursed by the bank anyway. Therefore, customers don’t need to pay extra for protection.

But this conclusion only makes sense if the additional insurance covers only what the bank already protects — namely, the costs of fraudulent credit card transactions.

Analysis of the options Option A : This contradicts the claim that the services are unnecessary.

Option B : Irrelevant. Availability isn’t the issue — necessity is.

Option C : This is the correct assumption. If the insurance did cover other things (e.g., lost time, legal costs, broader identity theft issues), then the argument would fall apart.

Option D : Too narrow, and not implied by the passage.

Option E : The argument doesn’t minimize the seriousness, just the need for extra insurance.

Full explanation

The principle in the original argument is:

Money raised from a specific activity should be spent on things closely related to that activity.

In the passage, this principle is applied to fuel taxes, arguing they should be spent on roads or transport (directly related), rather than unrelated areas like healthcare or defence.

Analysis of the options Option A : Both options are transport-related, so this is not really an application of the principle — it’s a preference within the same category.

Option B : This is a value judgment, not an application of the principle.

Option C : Again, this is a priority debate, not about matching source and use of funds.

Option D : This mirrors the principle: using money from sports for sports-related purposes.

Option E : This challenges taxation itself, not how tax revenue is used.

Full explanation

The passage builds the case that:

1. Poor children often lack glasses due to cost.

2. Free glasses lead to better test scores, equivalent to a year of schooling.

3. Better education improves future income and tax contributions.

4. The financial benefit outweighs the cost of the glasses.

Therefore, the logical conclusion is that the government should pay for the glasses — because it’s cost-effective and improves educational and economic outcomes.

Analysis of the options Option A : Irrelevant. The argument is about providing help, not marking adjustments.

Option B : Mentioned briefly, but not the main focus or conclusion.

Option C : The point is that glasses are equivalent to extra schooling, not that we should add schooling.

Option D : This is the main conclusion of the argument — the statement that all the other points are trying to support.

Option E : Not mentioned or implied.

Full explanation

The argument claims:

– Restrictions on alcohol sales to young people were meant to protect health.

– But instead, some started drinking dangerous non-beverage alcohols (like perfumes and medical spirits).

– So the conclusion is: remove the restrictions to reduce health risks.

The flaw here is that it only considers the harm caused by the restriction (i.e., drinking dangerous substitutes), but ignores the potential harm of lifting the restriction — namely, more underage drinking of actual alcohol, which could also cause serious health problems.

Analysis of the options Option A : The argument doesn’t say restrictions cause underage drinking generally — only that some turn to unsafe alternatives because of the restrictions.

Option B : Education is not part of the argument at all.

Option C : The issue discussed is access (legal restriction), not affordability.

Option D : Irrelevant — the argument is about health risks, not cultural norms.

Option E : This is the best statement of flaw. The argument falsely assumes that removing restrictions will improve health, without weighing the likely negative health consequences of more legal alcohol access.

Full explanation

There are two possible orders to visit the two towns – Arundel first or Chichester first – and in each case the return time is fixed by (1) the first connecting train from Three Bridges, (2) the earliest train out of the first town once the 4-hour minimum stay is up, (3) the earliest train out of the second town once its own 4-hour stay is up, and (4) the train that connection lands on into Victoria. Work out both orders and take whichever gets back to Victoria earlier.

Arundel first: the 8:45 from Three Bridges reaches Arundel at 9:32. Four hours later is 13:32, so the earliest train onward to Chichester is the first one departing at or after 13:32 – that’s the 14:02, arriving 14:24 (the earlier 13:29 departure is too soon). Four hours after 14:24 is 18:24, so the earliest train onward to Victoria is the first one departing at or after 18:24 – that’s the 18:37, arriving Victoria at 20:20.

Chichester first: the 8:45 from Three Bridges reaches Chichester at 9:34. Four hours later is 13:34, so the earliest train onward to Arundel is the first one departing at or after 13:34 – that’s the 13:41, arriving 14:12 (the earlier 13:25 departure is too soon). Four hours after 14:12 is 18:12, so the earliest train onward to Victoria is the first one departing at or after 18:12 – that’s the 18:13, arriving Victoria at 19:47.

Comparing the two: 19:47 (Chichester first) is earlier than 20:20 (Arundel first), so visiting Chichester first gives the earliest possible return.

Hence, the correct answer is (C), 19:47.

Full explanation

David Ricardo : Famous for the theory of comparative advantage, which supports international trade.

Thomas Robert Malthus : Known for the Malthusian theory of population, which argued that population growth would outstrip food supply, leading to famine and poverty.

Karl Marx : Critic of capitalism; developed Marxist theory, focusing on class struggle and advocating for socialism.

Vilfredo Pareto : Introduced the concept of Pareto efficiency in economics and the Pareto Principle Adam Smith : In “The Wealth of Nations” (1776), he introduced the invisible hand metaphor to describe how individuals’ pursuit of self-interest in a free market unintentionally benefits society.

Full explanation

Einstein’s general theory of relativity : presented on 25 November 1915 by Albert Einstein. Describes gravity as the curvature of spacetime due to mass and energy. Replaced Newton’s theory of gravity on cosmic scales.

String Theory : A theoretical framework where point-like particles are replaced by one-dimensional strings. Emerged in the late 20th century, not in Einstein’s era. Still unproven.

Quantum Theory : Originated with Max Planck (1900) and later developed by Einstein, Bohr, Heisenberg, etc. Describes physical phenomena at atomic and subatomic levels.

The Big Bang Theory : Explains the origin of the universe from an initial singularity—not related to the 1915 event.

Dalton’s Atomic Theory : Proposed by John Dalton in the early 1800s.

Laid the foundation for modern atomic chemistry, describing atoms as indivisible units.

Full explanation

Before meiosis, the cell undergoes interphase, during which DNA content replicates. This ensures that each chromosome consists of two sister chromatids. So, statement 1 is correct.

Spindle fiber formation occurs during prophase I which is part of meiosis itself — not before it. So, statement 2 is incorrect.

Crossing over occurs during prophase I — specifically in the pachytene stage. So, again, this happens during meiosis, not before it. Statement 3 in incorrect.

Full explanation

Capsid : HIV contains capsid which serves as a protein shell surrounding the viral RNA. Since it’s a protein, it contains peptide bonds.

Envelope : Envelope is the lipid bilayer derived from the host cell membrane. Since the cell membrane contains protein channels and other signaling proteins, it contains peptide bonds.

Reverse transcriptase : This is a viral enzyme responsible for converting viral RNA into DNA. As an enzyme, it’s a protein —- therefore, it contains peptide bonds.

Full explanation

1. Germinal epithelial cells in the ovary

– These are somatic cells that give rise to oogonia.

– Ploidy: Diploid (2n)

2. Oogonia

– Formed from germinal epithelial cells via mitosis.

– Ploidy: Diploid (2n)

3. Primary oocyte

Formed from oogonia via growth phase, still no meiosis yet.

Ploidy: Diploid (2n)

Begins meiosis I, but is arrested in prophase I until puberty.

4. Secondary oocyte

– Formed after meiosis I completes at puberty.

– Meiosis I is a reduction division, so:

– Ploidy: Haploid (n)

– It is arrested in metaphase II until fertilization.

Diploid cells: 1 (germinal epithelial cells), 2 (oogonia), and 3 (primary oocyte)

Haploid cell: 4 (secondary oocyte)

Full explanation

Analysis of the given statements

Statement 1 : They alter the shape of the active site.

Incorrect. Only non-competitive inhibitors alter the enzyme’s shape. Competitive inhibitors do not change the shape — they just block the active site.

Statement 2 : They denature the enzyme.

Incorrect. Most reversible inhibitors do not denature the enzyme.

Statement 3 : They increase the activation energy of the reaction.

Incorrect. Enzyme inhibitors reduce the rate of reaction but do not directly increase activation energy.

Statement 4 : They reduce the rate of the enzyme catalysed reaction.

Correct. All enzyme inhibitors — regardless of mechanism — lower the reaction rate by interfering with enzyme function.

So, only statement 4 is correct.

Full explanation

Analysis of the given options

Option A : rRNA has anticodons which bind to tRNA.

Incorrect. rRNA does not have codons or anticodons. It forms the core of the ribosome and helps catalyze protein synthesis. tRNA has anticodons that bind to codons on mRNA, not rRNA.

Option B : Prokaryotic DNA is a single strand which forms a loop.

Incorrect. Prokaryotic DNA is double-stranded. It does form a loop, i.e. circular, but is not single-stranded.

Option C : tRNA is made up of one phosphate-sugar backbone and may have adenosine and thymine bases.

Incorrect. Thymine is not found in RNA. Uracil is used instead of thymine.

Option D : mRNA is made up of a single nucleotide with a codon of uracil, cytosine and guanine bases.

Incorrect. mRNA is made up of a long chain of nucleotides (at least 3 nucleotides for a codon), not just one.

Option E : Bases in DNA may form hydrogen bonds with uracil bases.

During transcription, RNA polymerase synthesizes a complementary mRNA strand and mRNA hydrogen bonds with DNA before it gets released. This is a correct statement.

Full explanation

Analysis of the given statements

Statement 1 : During inspiration, the pressure within the chest cavity is lower than outside the body.

Correct. Humans breathe via the negative pressure inhalation in which the thoracic cavity expands first, lowering the pressure inside below the atmospheric pressure, leading to inspiration — drawing air into the lungs.

Statement 2 : During ventricular systole, the pressure in the atrium is lower than in the ventricles.

Correct. During the ventricular systole, ventricles contract while AV valves are closed, increasing pressure in the ventricles. Meanwhile, the atria are relaxed, so their pressure is lower than that in the ventricles.

Statement 3 : During ventricular systole, the pressure in the aorta is lower than the pressure in the atrium.

Incorrect. During the ventricular systole, the ventricular pressure exceeds aortic pressure, allowing the aortic valve to open. But the aortic pressure remains significantly higher than atrial pressure, as it’s needed to drive blood throughout the body.

So, statements 1 and 2 are correct.

Full explanation

Relating to the Excretory system and reproductive system, the pituitary gland produces 3 hormones.

ADH — Reduces urine output by promoting water reabsorption in kidneys LH — Stimulates ovulation in females, testosterone production in males FSH — Stimulates egg maturation in females, sperm production in males When pituitary function is reduced, the mentioned functions will be reduced as a result.

Analysis of the given statement Statement 1 : more urine produced in a male or female.

Correct. Reduced pituitary function = reduced ADH → Less water reabsorbed → More urine produced.

Statement 2 : infertility in a female Correct. A lack of LH and FSH disrupts the menstrual cycle and ovulation leading to infertility.

Statement 3 : infertility in a male Correct. A lack of LH and FSH leads to reduced sperm and testosterone, resulting in infertility.

Full explanation

Cell wall : It is composed of cellulose which contains glucose monomers.

Cell membrane : In cell membrane, carbohydrates are typically found attached to proteins (forming glycoproteins) or lipids (forming glycolipids) on the outer surface of the cell membrane. They are important for various cellular functions.

Nucleolus : It is the site of rRNA and ribosome production. So, it contains nucleic acids which are composed of ribose sugar, phosphate and base group. Therefore, nucleolus contains carbohydrate monomers.

Mitochondrion : Small circular DNAs can be found inside mitochondria which contain ribose sugar as a component. So, mitochondria also contains carbohydrate monomers.

Full explanation

Given :

Analysis of the given statements

Statement 1 : Molecules of Q move by facilitated diffusion from cell X.

Incorrect. Without energy expenditure (in facilitated diffusion), molecules move from higher concentration to lower concentration. So, molecules would move from cell Y to cell X, not in reverse direction.

Statement 2 : Molecules of Q move by active transport into cell Y.

Correct. With energy expenditure (in active transport), molecules can move from lower concentration (Cell X) to higher concentration (Cell Y).

Statement 3 : Molecules of R move into and out of both cell X and cell Y.

Correct. When the concentration in two cells separated by a membrane is in equilibrium, molecules move in and out of the cells, without changing the concentration.

Thus, statement 2 and 3 are correct.

Full explanation

Damage to the cerebrum, particularly areas like the hippocampus (part of the temporal lobe), can lead to loss of memory. The cerebrum is responsible for memory, conscious thought, voluntary movement, learning, personality.

Spinal cord is mainly responsible for transmitting nerve signals between the brain and body.

Medulla – Controls vital functions (e.g., breathing, heartbeat)

Cerebellum – Balance, coordination, fine motor skills Hypothalamus – Regulates body temperature, hunger, hormones

Full explanation

Student 1 : Information for both animal cells and bacterial cells are correct. Animal cell is an eukaryotic cell and the genetic material is stored in a specific double membrane bound place called the nucleus. Bacterial cells contain 70S ribosomes while eukaryotic cells contain larger 80S ribosomes.

Student 2 : Information provided for both categories is not correct. Liver cells do not possess cell walls. Cell wall is usually a feature of plant cells. Bacteria is a prokaryote and its characteristic is that it does not contain membrane bound organelles including mitochondria.

Student 3 : Though the fact about animal cells is true, that about bacterial cells is completely false. 70S ribosomes are present in the mitochondria of liver cells. In the case of bacterial cells, they are prokaryotes and its characteristic is that it does not contain membrane bound organelles including nucleus. So, genetic material is stored in the designated area inside in the cytoplasm called the nucleoid.

Student 4 : Both facts are correct. Animal cells like liver cells contain circular DNA inside the mitochondria. Prokaryotes contain plasmids that carry extra genes that provide them with additional traits or advantages, especially in specific environments.

Therefore, student 1 and 4 gave totally correct answers

Full explanation

DNA sequence given

CAT TGG GCA TCG

Analysis of the given statements

1. 2 H-bonds form between A – T and 3 H-bonds form between G – C. There are 5 As and Ts in the sequence, so 10 H-bonds form. There are 7 Gs and Cs in the sequence, so 21 H-bonds form.

In total — 21 + 10 = 31 H-bonds (not 29 bonds). Therefore, the given statement is incorrect.

2. Phosphodiester bonds connect nucleotides in a single strand.

For n nucleotides in a single strand, there are (n — 1) phosphodiester bonds:

12−1 = 11 bonds The given statement is incorrect because it says 12 bonds.

3. In RNAs, Uracil base is used instead of thymine.

Given DNA sequence : CAT TGG GCA TCG mRNA sequence : GUA ACC CGU AGC tRNA sequence : CAU UGG GCA UCG So, it is true that the tRNA molecules contain a total of 3 uracil bases.

Full explanation

Cystic fibrosis (CF) is inherited in an autosomal recessive pattern.

This means:

– A person needs two copies of the defective gene (homozygous recessive) to have the condition.

– Carriers have one normal and one faulty gene (heterozygous) and do not show symptoms.

Parents don’t have CF, but their child does → So both parents must be carriers.

Let’s denote:

– C = normal allele

– c = allele for CF

So:

– Mother = Cc

– Father = Cc

Punnett square

So, probability of a children without cystic fibrosis (2 Cc and CC) = (3)/(4)

Probability of a baby being male = (1)/(2)

Probability to get a boy without cystic fibrosis = (1)/(2) × (3)/(4) = (3)/(8)

Full explanation

Glycolysis is a process where one glucose is broken down into 2 pyruvates through several steps. During glycolysis, net 2 ATP and 2 NADH (reduced NAD) are produced. No CO₂ is produced.

During pyruvate decarboxylation, 1 CO₂ and 1 NADH are produced.

A product that is produced in both processes is NADH/ reduced NAD.

Full explanation

Human haemoglobin molecule has four polypeptide chains : 2 alpha (α) and 2 beta (β) chains. These interact to form one functional protein.

Thus, it has a quaternary structure.

Quaternary structure develops due to the existence of primary, secondary and tertiary structures.

Thus, haemoglobin has all four levels of protein structure: Primary, Secondary, Tertiary, and Quaternary.

Full explanation

The main pump that contributes to the resting membrane potential is the sodium–potassium pump (Na⁺/K⁺ ATPase). It is an active transporter.

There is also K⁺ leaks out of the neuron through K⁺ leak channels. The movement is passive through protein channels and it is a form of facilitated diffusion.

Since ATP is needed to fuel the Na⁺/K⁺ pump, respiration also indirectly supports resting potential.

So, all three processes take place during the establishment of the resting potential.

Full explanation

Option A : This option correctly states the Kelvin cycle steps of photosynthesis.

Option B : Incorrect. Light splits water → produces H⁺, e⁻, and O₂ (not OH⁻ combining with anything).

Option C : Incorrect. This is describing aerobic respiration, not photosynthesis.

Option D : Incorrect. CO₂ is not split by light. Light splits water, not CO₂.

Option E : Incorrect. CO₂ fixation occurs in light-independent reactions.

Full explanation

Transgenic DNA refers to DNA that has been artificially introduced into an organism from a different species. So, it could be any DNA with a foreign DNA from another species — such as

1. invertebrate animal DNA in mammal DNA

2. prokaryotic DNA in plant DNA

3. plant DNA in animal DNA

Full explanation

Option A : Salt solution is homogeneous but paper filtration cannot separate dissolved salt.

Option B : Salt solution is homogeneous, not heterogeneous Simple distillation can separate water, but mixture type is wrong.

Option C : Plant pigment solution is homogeneous and chromatography is perfect for separating pigments like chlorophyll. Thus, this is correct.

Option D : Blood is a heterogeneous mixture (plasma + cells). Centrifuge is the correct method, but wrong mixture type.

Option E : Crude oil is homogeneous at a macro level. Needs fractional distillation, not simple distillation.

Full explanation

The symbol ₈¹⁶O²⁻ is giving you two separate pieces of information. The subscript 8 is the atomic number, so a neutral oxygen atom has 8 protons – and, being neutral, 8 electrons too. The superscript 2− then tells you this particular ion has picked up 2 extra electrons on top of that, bringing the total to 10 electrons. (The mass number, 16, is protons + neutrons – it plays no part in working out the electron count.)

Now build up the configuration for those 10 electrons, filling the lowest-energy sub-shells first (the Aufbau principle):

• 1s holds up to 2 electrons → 1s² (2 placed, 8 left)
• 2s holds up to 2 electrons → 2s² (4 placed, 6 left)
• 2p holds up to 6 electrons → 2p⁶ (10 placed, 0 left)

That gives 1s² 2s² 2p⁶ – the same electron arrangement as neon. That makes sense: gaining 2 electrons is exactly what pushes an oxygen ion up to the electron count of the nearest noble gas, so O²⁻ is isoelectronic with Ne.

Thus, the correct option is option E.

Full explanation

An oxidising agent is the substance that causes oxidation (it gains electrons and is reduced). So, we have to look for changes in oxidation states or electron transfer.

Option A : Cl₂ + 2KBr → 2KCl + Br₂ Cl₂ (0) → Cl⁻ (−1): Cl₂ is reduced.

Br⁻ (−1) → Br₂ (0): Br⁻ is oxidised Cl₂ is the oxidising agent (it accepts electrons from Br⁻)

Option B : Zn + CuSO₄ → ZnSO₄ + Cu Zn (0) → Zn²⁺: oxidised Cu²⁺ → Cu (0): reduced Zn is the reducing agent, not the oxidising agent.

Option C : 3CO + Fe₂O₃ → 3CO₂ + 2Fe

CO → CO₂: C goes from +2 to +4 (oxidised)

Fe³⁺ → Fe: reduced

CO is oxidised, so it’s the reducing agent.

Option D : H₂SO₄ + 2NaOH → Na₂SO₄ + 2H₂O

This is a neutralisation reaction (acid + base → salt + water)

No redox — no oxidising or reducing agents

Option E : 2Mg + O₂ → 2MgO

O₂ (0) → O²⁻ (−2): reduced

Mg (0) → Mg²⁺: oxidised

Mg is the reducing agent here.

Full explanation

Given:

Initial concentration of HCl (C) = 1.0 mol/L

Volume taken (V) = 10 mL = 0.010 L

Final volume after dilution = 1.0 L

Step 1: Calculate the number of moles of HCl added

Moles of HCl = C×V = 1.0×0.010 = 0.010 mol

Step 2: Calculate the concentration after dilution

New concentration = (number of mole )/(Volume of solution) = (0.010 mol )/(1 L ) = 0.010 mol/l

Step 3: Calculate the pH

HCl is a strong acid, so it fully dissociates:

[H⁺] = 0.010 mol/l = 1 × 10^{– 2} mol/l

pH = – log [H⁺] = – log [ 10^{– 2}] = 2

Full explanation

Since all gases are at 0 °C and 1 atm, we can use:

1 mole of gas = 22.4 L

Number of particles = number of moles × Avogadro’s number (so we just need to compare moles)

Option A : 33.6 L of chlorine gas Molar volume = 22.4 L/mol Mole = (33.6L)/(22.4 L/mol) = 1.5 mol Option B : 66.0 g of carbon dioxide gas Molar mass = 12 + (16×2) = 44 g/mol Mole = (66 g)/(44 g/mol ) = 1.5 mol Option C : 22.4 L of hydrogen gas Molar volume = 22.4 L/mol Mole = (22.4L)/(22.4 L/mol) = 1 mol Option D : 10.0 g of helium gas Molar mass = 4 g/mol Mole = (10g)/(4 g/mol) = 2.5 mol Option E : 64.0 g of oxygen gas Molar mass = 16×2 = 32 g/mol Mole = (64g)/(32 g/mol) = 2 mol

In comparison, 10.0 g of helium gas contains the most particles.

Full explanation

3F₂(g) + Cl₂(g) → 2ClF₃(g)

This tells us that:

3 volumes of F₂ react with 1 volume of Cl₂ to form 2 volumes of ClF₃.

Given volume : F₂: 150 cm³, Cl₂: 100 cm³

F₂ is the limiting reagent and we have 100 cm³ of Cl₂, which is in excess.

150 cm³ of F₂ would need 50 cm³ of Cl₂.

From the equation: 3 volumes of F₂ → 2 volumes of ClF₃ So 150 cm³ of F₂ → 2 × (150)/(3) = 100 cm³ of ClF₃.

After reaction:

F₂: 0 cm³ (completely used up)

Cl₂: Used = 50 cm³ → Left = 100 − 50 = 50 cm³

ClF₃ (product) = 100 cm³

So, Final volume = Unreacted Cl₂+ClF₃ formed = 50+100 = 150 cm³

Full explanation

Structural isomers, also known as constitutional isomers, are molecules with the same molecular formula but different structural formulas (different connectivity of atoms).

Methylcyclopentane has molecular formula of C₆H₁₂

Option A : Hexane has molecular formula of C₆H₁₄. So, this cannot be the isomer of methylcyclopentane.

Option B : Cyclohexene has molecular formula of C₆H₁₀. This also cannot be the isomer of methylcyclopentane.

Option C : Hex-2-ene has molecular formula of C₆H₁₂. This compound has the same molecular formula as methylcyclopentane with different structures (with double bond). Therefore, this is the correct structural isomer of methylcyclopentane.

Option D : 2,2-dimethylbutane has molecular formula of C₆H₁₄. Not an isomer.

Option E : 2-methylpentane has molecular formula of C₆H₁₄. Not an isomer.

Full explanation

In an aqueous solution of sodium chloride, there will be water molecules and sodium chloride in their ionic states — Na⁺ and Cl⁻. Therefore, water is a covalent compound — a molecule. And Na⁺ and Cl⁻ are ions. There is no single atom involved.

Thus, the correct option is option A.

Full explanation

Solubility of a substance is the maximum amount of that substance that can be dissolved in a particular solvent at a given temperature.

And the solubility constant K_sp is temperature dependent. For a solution that consists of a gas, the constant will also depend on pressure. Greater K_sp leads to greater solubility of the solute. Generally speaking, the solubility product constant increases with increasing temperature for non-gas solutes. Therefore, if potassium nitrate is cooled down to 25 °C from 80 °C, the K_sp decreases, leading to lesser solubility and consequently, deposition of undissolved potassium nitrate. Since less potassium nitrate dissolves in the solution, its concentration is diluted, however, both the solvent and solution are in a closed container, the total mass of the solvent will remain unchanged.

Thus, among the given 3 facts, only fact 1 and 3 are correct.

Full explanation

From the first given fact “Element X is a grey solid”, we can exclude the gas element from the options — Fluorine.

Then, the question said it combines with chlorine to form a polar molecule with the formula XCl with oxidation number of +1.

From this fact, we can exclude Manganese from the option which usually has variable oxidation numbers between +2 and +7 : not +1.

We can also exclude carbon because carbon usually bonds with chlorine with +4 oxidation number, forming CCl4.

Now, we are down to 2 choices — Lithium and Iodine.

Let’s look at the last fact — it says that in potassium iodide solution, it dissolves to form a coloured solution. At 500 °C, it becomes a coloured vapour. Lithium metal usually does not dissolve in solutions (only its ionic compound state dissolves). So, we can exclude Lithium.

Iodine sublimes on heating — it turns directly from solid to gas.

The vapour is a distinct violet or purple color.

This is a characteristic property of elemental iodine.

Thus, the element X is iodine.

Full explanation

Lewis structure of silicane

According to the lewis structure, the central atom “Silicon” has 4 electron domains without any lone pair of electrons.

Thus, the shape of the molecule will be tetrahedral with a bond angle of 109.5°.

Thus, the correct option is option C.

Full explanation

Since the options are about proton, electron and neutron numbers c comparison, we will find these numbers for individual atoms/ions first.

²³₁₁Na⁺ Number of protons = 11 Number of neutrons = 23-11 = 12 Number of electrons = 11-1 = 10 ¹⁶₈O²⁻ Number of protons = 8 Number of neutrons = 16-8 = 8 Number of electrons = 8 + 2 = 10 ¹⁸₈O Number of protons = 8 Number of neutrons = 18-8 = 10 Number of electrons = 8 ³²₁₆S Number of protons = 16 Number of neutrons = 32-16 = 16 Number of electrons = 16 Analysis of the given options Option A : ¹⁶₈O²⁻ and ¹⁸₈O do not have the same number of electrons. Therefore, this option is false.

Option B : Not only ²³₁₁Na⁺ has two more electrons than ¹⁸₈O — ¹⁶₈O²⁻ also have 2 more electrons than that. Thus, this option is false.

Option C : ¹⁶₈O²⁻ has four fewer neutrons than ²³₁₁Na⁺. Thus, this option is correct.

Option D : ³²₁₆S has five more neutrons than ²³₁₁Na⁺, not four. Thus, this option is false.

Option E : ¹⁶₈O²⁻ and ³²₁₆S do not have the same number of protons. Thus, this option is false.

Full explanation

Track the car’s net east-west and north-south displacement. East-west: 3.0 km east then 6.0 km west = 3.0 km net west. North-south: 4.0 km south then 8.0 km north = 4.0 km net north.

These two net displacements (3 km west, 4 km north) are perpendicular, so the straight-line distance from X is found with Pythagoras’ theorem: distance = √(3² + 4²) = √(9 + 16) = √25 = 5.0 km.

Hence, the correct answer is (A).

Full explanation

The power dissipated by a resistor is given by P = I²R, where I is the current and R is the resistance.

P = (10 A)² × 5.0 Ω = 100 × 5 = 500 W.

Hence, the correct answer is (E).

Full explanation

The mean of three numbers is their sum divided by 3, so here mean = [x/3 + x + (x + 6)] ÷ 3. First combine the three terms of the sum into a single fraction, by rewriting the whole-number terms with the same denominator (3) as x/3:

x3+ x + (x + 6) =x3+3x3+3x + 183=7x + 183

Now divide that single fraction by 3 — dividing a fraction by a number simply multiplies its denominator by that number:

mean =7x + 183÷ 3 =7x + 189

Hence, the correct answer is (D).

Full explanation

The gradient of a line through (x₁, y₁) and (x₂, y₂) is m = (y₂ − y₁)/(x₂ − x₁).

With (x₁, y₁) = (2, −3) and (x₂, y₂) = (−1, 6): m = [6 − (−3)] / (−1 − 2) = 9 / (−3) = −3.

Hence, the correct answer is (C).

Full explanation

Use logarithm properties to simplify log₁₀(14/3) = log₁₀14 − log₁₀3.

Since 14 = 2 × 7: log₁₀14 = log₁₀(2 × 7) = log₁₀2 + log₁₀7.

So log₁₀(14/3) = log₁₀2 + log₁₀7 − log₁₀3 = y + x − z = x + y − z.

Hence, the correct answer is (C).

Full explanation

By Archimedes’ Principle, the upthrust equals the weight of the fluid displaced. Since the cube is fully immersed, the volume of oil displaced equals the cube’s own volume: V = a³.

Mass of displaced oil = density of oil × volume = σ × a³.

Upthrust = weight of displaced oil = mass × g = σa³g.

Hence, the correct answer is (D).

Full explanation

By the First Law of Thermodynamics, ΔQ = ΔU + ΔW, where ΔQ is heat supplied to the system, ΔW is work done by the system on its surroundings, and ΔU is the change in internal energy.

Here ΔQ = 3500 J and ΔW = 3500 J, so ΔU = ΔQ − ΔW = 3500 J − 3500 J = 0.

Since the internal energy is unchanged, the temperature of the gas (which determines internal energy for an ideal gas) stays constant — this is an isothermal process.

Hence, the correct answer is (B).

Full explanation

This is a permutation of a multiset. The number of distinct arrangements is n! / (n₁! × n₂! × … × nₖ!), where n is the total number of items and each nₗ is the count of a repeated item.

Here n = 5 (letters A, A, B, B, C), with A repeated twice and B repeated twice: number of arrangements = 5! / (2! × 2! × 1!) = 120 / (2 × 2 × 1) = 120/4 = 30.

Hence, the correct answer is (E).