IMAT 2019 Worked Solution

Correct Answer: B) 15

Correct answer: D

The argument assumes that fun and education are separate, implying that making a lesson enjoyable does not contribute to learning. This ignores the possibility that students who enjoy their lessons might actually learn better.

Option A: The statement that education is not about happiness may be debatable, but it’s not a flaw in reasoning.

Option B: The flaw in the argument is about how lessons are judged, not about defining education.

Option C: The real flaw is that the argument ignores the link between fun and learning, not just that it exaggerates.

Option D: The argument ignores this possibility, making it a flaw. This is a correct option.

Option E: The flaw is not about patronizing students but about ignoring the benefits of fun in learning.

Correct Answer: D) £16.00

Correct Answer: Option C

The argument claims that wooden floors are more eco-friendly than carpets because carpets are plastic-based and use petrochemical underlay. It then concludes that wooden floors will remain in fashion due to their environmental benefits.

Option A: This might be a reason to prefer wooden floors, but it does not weaken the argument about eco-friendliness.
Option B: The argument already assumes wooden floors have an eco-friendly advantage, so this fact does not contradict it; instead, it strengthens it.
Option C: If most laminate and wood floors also use petrochemicals, then the argument’s main justification for wooden floors being more eco-friendly is weakened. This directly challenges the claim that wooden floors align with "eco-friendly aspirations," making it the strongest way to weaken the argument. Thus, this is the correct option.
Option D: This challenges the durability of wooden floors, but the argument is not based on durability. The argument claims wooden floors will remain in fashion due to eco-friendliness, not longevity.
Option E: It does not directly weaken the claim that wooden floors are eco-friendly. The argument is about wooden floors’ impact, not the decline of synthetic carpets.

Correct Answer: C) 3

Correct Answer: D

The passage discusses a study on brain training for people aged 65+. Key findings are mentioned. The study does not claim that training prevents dementia entirely. Instead, it shows that brain training delays its onset. We need to choose the option that is directly supported by the findings mentioned in the argument.

Option A: The passage mentions that brain training improved everyday activities like housework. However, it does not say that older people generally do less housework over time. This statement is not supported by the passage.

Option B: The passage states that those who had brain training experienced faster decline once diagnosed with dementia. However, it does not say whether this is preferable for any person with a diagnosis.

Option C: The passage only discusses people who voluntarily participated in brain training. There is no mention that older adults avoid mental challenges unless forced. This is an unsupported generalization.
Option D: This is directly supported: trained individuals developed dementia later than those in the control group. This matches the findings, making it the best conclusion.

Option E: The study showed that brain training benefits lasted for five years, but it does not say that everyone who took part lived that long.
This is an incorrect assumption based on the wording.

Correct Answer: D

The passage discusses whether Near-Death Experiences (NDEs) are purely physiological.

Option A: It is a fact from the passage, not the main conclusion.
The passage uses this fact to support its main claim but does not argue for this specifically.
Option B: It is just a fact supporting the argument, not the conclusion.
Option C: This contradicts the argument! The passage challenges the idea that oxygen deficiency is the sole cause of NDEs. The study suggests that oxygen deficiency alone is not enough to explain NDEs.
Option D: This perfectly matches the passage’s reasoning.
Since cerebral anoxia alone does not explain all NDEs, there must be other, non-physical factors involved. This is the best conclusion that logically follows from the argument.
Option E: The passage argues against the idea that NDEs are purely physical. Since not everyone with cerebral anoxia has NDEs, the passage suggests that other factors (not just physical ones) must be involved.

Correct Answer: D) 3.8 m

The box has 4 lateral sides and 2 up and down sides.
2 opposite sides will need the same length of string.

For the first pair of lateral sides, 60 cm of string (40 cm for length and 20 cm for height) is needed.

For the second pair of lateral sides, 50 cm of string (30 cm for width and 20 cm for height) is needed.

For each up or down side, 70 cm of string (30 cm for width and 40 cm for length) is required.

Total length of string needed = length of 4 lateral sides + length of up and down sides + length for the knot = 2 (60cm) + 2 (50cm) + 2 (70cm) + 20 cm = 380 cm

Thus, the correct option is option D) 3.8 m

Correct Answer: D

A document has been prepared to include the images and diagrams related to the questions, placed directly below the worked solutions for clarity and reference.

Correct Answer: E) The records provide accurate information about the catch of marlin off the Madeira coast.

The passage explains that the recent drop in the marlin catch:
- Is not due to environmental conditions
- Is not due to human factors
- Follows a historical pattern of five-year declines alternating with fifteen-year increases, based on six centuries of fishing records.
- Conclusion: The decline is part of a natural long-term cycle.

An assumption is something unstated but necessary for the argument to hold.

For the conclusion (that the marlin catch follows a natural cycle) to be valid, the researchers must have used reliable historical records. If the records were inaccurate, then the entire pattern could be invalid, and the argument would fall apart.

Thus, the assumption is: E. The records provide accurate information about the catch of marlin off the Madeira coast.

Correct Answer: B) Harper Lee

Harper Lee wrote To Kill a Mockingbird, which was published in 1960. The novel is a classic of American literature and deals with themes of racial injustice, moral growth, and empathy. It is set in the American South during the Great Depression and follows Scout Finch, a young girl whose father, Atticus Finch, defends a Black man falsely accused of a crime.

Correct Answer: B) To encourage peaceful trade between nations

The United Nations (UN) was established in 1945 to promote international cooperation and prevent future conflicts. Its main purposes are outlined in the UN Charter, and they include:

1. To maintain international peace and security
2. To develop friendly relations among nations
3. To achieve international co-operation in solving international problems
4. To be a centre for harmonizing the actions of nations

While the UN supports economic cooperation, it does not focus directly on trade. Trade is mainly handled by other organizations like the World Trade Organization (WTO) and the International Monetary Fund (IMF).
The UN is not responsible for setting trade policies or enforcing trade agreements.

Thus, the purpose that is not stated is option B. To encourage peaceful trade between nations

Correct Answer: A) Giacomo Puccini

Madama Butterfly is a famous opera composed by Giacomo Puccini in 1904. It tells the tragic story of Cio-Cio-San (Madama Butterfly), a young Japanese woman who falls in love with an American naval officer, Pinkerton, only to be abandoned and betrayed. The opera is known for its emotional depth and beautiful music, including the famous aria "Un bel dì, vedremo".

Correct Answer: E) Sweden

On 1 January 2002, twelve European Union (EU) countries officially adopted Euro coins and banknotes as their currency. These countries were:

Austria, Belgium, Finland, France, Germany, Greece, Ireland, Italy, Luxembourg, the Netherlands, Portugal, and Spain. Sweden, the United Kingdom, and Denmark chose NOT to adopt the Euro.

Correct Answer:A) A Midsummer Night’s Dream

Many of Shakespeare’s plays are set in Italy, but A Midsummer Night’s Dream is NOT one of them. Instead, it takes place in Athens, Greece, and the surrounding mystical forest. The play follows the romantic entanglements of four lovers, the antics of the fairy king and queen (Oberon and Titania), and the mischievous Puck.

Correct Answer: C) The October Revolution in the Russian Empire

The building of the Taj Mahal - 1632–1653 CE
The crowning of Charlemagne - 800 CE
The October Revolution in the Russian Empire - 1917
The Taiping Rebellion in China - 1850–1864 CE
The fall of the Western Roman Empire - 476 CE

Correct Answer: D) Marie Curie

Marie Curie was the first woman to be awarded a Nobel Prize in 1903. She won the Nobel Prize in Physics along with Pierre Curie and Henri Becquerel for their work on radioactivity.

She later became the first person ever to win two Nobel Prizes, receiving the Nobel Prize in Chemistry in 1911 for her discovery of radium and polonium.

Correct Answer: E) Game theory

The Prisoner’s Dilemma is a famous concept in game theory, a branch of mathematics that studies strategic decision-making.

Correct Answer: B) Hinduism

Hinduism is not attributed to a single founder or a specific revelation to one individual. Instead, it evolved over thousands of years through a combination of religious traditions, cultural practices, and sacred texts like the Vedas and Upanishads. It is considered the world's oldest major religion and has no single point of origin or founding figure.

Correct Answer: C) The Constituent Assembly

The Constitution of the Italian Republic was enacted on 22 December 1947 by the Italian Constituent Assembly (Assemblea Costituente), which was elected in 1946 after the fall of Fascism and the end of World War II.

Correct Answer: C) The Poems of Rumi – China

The Poems of Rumi were not written in China. They were composed by Jalal al-Din Rumi, a Persian poet from the 13th century, in the Persian Empire (Iran).

Correct Answer: E) Legislative – executive – judicial

Separation of powers is a fundamental principle in modern democratic states. It ensures that:
● Legislative power (e.g., Parliament, Congress) makes the laws.
● Executive power (e.g., President, Prime Minister, Government) enforces the laws.
● Judicial power (e.g., Courts, Judges) interprets and applies the laws.

This system prevents the concentration of power in one branch and promotes checks and balances.
Thus, the correct answer is option E) Legislative – executive – judicial

Correct Answer: A) one coccus bacterium in a Staphylococcus cluster

Correct Answer: A) row 3

B lymphocytes are formed and mature in the bone marrow. Then, they are stored and activated in the spleen and lymph nodes, where they turn into plasma cells to produce antibodies. Because these antibodies dissolve and act in the blood, this division is called humoral immunity.

For T cells, they are produced in the bone marrow and mature in the thymus. They are the agents of cell-mediated immunity because they coordinate the immune system and directly kill virally infected cells.

Thus, the correct row for B lymphocytes is row 3.

Correct answer: C) Row 3

Correct Answer: D) Sister chromatids are pulled by the spindle fibers towards opposite poles of the cell.

During anaphase of mitosis, the centromeres split, and sister chromatids are pulled apart. The spindle fibers (microtubules) shorten, pulling chromosomes to opposite poles of the cell. Non-kinetochore microtubules push against each other, lengthening the cell.

Option A: Chromatin condensation occurs mainly in Prophase.

Option B: Centrioles migrate to opposite poles mainly in Prophase.

Option C: DNA replication occurs in the S phase of the cell cycle. It is not part of the mitosis process.

Option D: This statement correctly describes the process of anaphase.

Option E: Chromosomes align at the equator of the cell during metaphase.

Thus, the correct option is option D.

Correct Answer: C

In the Sympathetic nervous system, preganglionic neurons are short, myelinated, and synapse in a ganglion that exists just outside the spinal cord. Postganglionic neurons are long, unmyelinated, and extend to the target organ. Sympathetic nerves arise from the thoraco-lumbar region of the spinal cord.

In the Parasympathetic nervous system, preganglionic neurons are long, myelinated, and synapse in a ganglion that exists close to the target organ. Postganglionic neurons are short and unmyelinated. Parasympathetic nerves arise from the brainstem and sacral part of the spinal cord.

Option A: There is no ganglion, So this is not a possible pathway for the parasympathetic Nervous system. Since the nerve pathway passes through the dorsal root, connecting between brain and the target organ, it should be a cranial nerve (sensory).

Option B: Ganglion is present, but it is close to the spinal cord. Thus, this is not a correct option. This image represents the sensory pathway for the sympathetic nervous system.

Option C: Ganglion is present, and it is close to the target organ. Thus, this is a possible route for impulses passing along a parasympathetic neuron.

Option D: No ganglion is present. Thus, this is not a possible pathway for the parasympathetic Nervous system. This could be the motor pathway of a spinal nerve.

Option E: No ganglion is present. Thus, this is not a possible pathway for the parasympathetic Nervous system. This could be the sensory pathway of a spinal nerve.

Correct Answer: B) row 4

Viruses derive their envelope from the host’s cell membrane. Thus, it is composed of a double layer of phospholipids. (Phosphate + 2 fatty acid chains + glycerol)

Viral capsids are mainly composed of several types of proteins (polymers of amino acids)

Genetic material can be DNA or RNA, single-stranded or double-stranded. (nucleotides joined together by phosphodiester bonds)

Thus, the row that shows the correct component of the 3 structures is row 4.

Correct Answer: D) 1 only

Organisms contain the same set of genes in every cell in the body, and the difference in gene expression is due to the regulatory factors that turn on or off specific genes. Thus, among the three statements that the student wrote, only the first statement is correct.

The 2nd statement is wrong because genes are the same and alleles are the same in both white hair follicle cells and black hair follicle cells.

The third statement is wrong for the same reason. White hair follicles cannot have specific recessive alleles for their cells.

Thus, the correct option is option D. 1 only.

Correct Answer: E) 1 and 3 only

A tissue is a group of similar cells that work together to perform a specific function. There are 4 main types of tissues: Epithelial, connective, nervous, and muscle tissues.

An organ is a structure made up of different types of tissues working together to perform a specific function.

Among the 3 given structures, cartilage (connective) and endothelium are tissues, and skin is an organ that is composed of blood vessels (contains all types of tissue), epithelium, and nerves.

Correct Answer: A) 1, 2, and 3

P ATT CCG GGA TTC CCT
Q ATT CCG GAT TGC ACT

Addition: A mutation where one or more nucleotides are added to the DNA sequence.

Deletion: A mutation where one or more nucleotides are removed from the DNA sequence.

Substitution: A mutation where one nucleotide is replaced by another.

Comparing the two given nucleotide sequences, differences appear starting from the 3rd triplet.

In P, if Guanine is deleted in the third triplet (deletion) and G is added between T and C in the fourth triplet (addition), and first C is replaced by A in the last triplet (substitution), it will result in the Q sequence.

Thus, all three types of mutations – addition, deletion, and substitution – can explain the differences between P and Q.

Correct Answer: E) Row 3

An experiment is done to observe the effect of various chemicals (dilute HCl, ethanol, and water at 20 °C) on the permeability of the cell surface membranes.

Ethanol is a nonpolar solvent that can dissolve the lipid bilayer and increase membrane permeability.

HCl is an acid, and even when diluted, it can denature membrane proteins by disrupting hydrogen bonds and ionic interactions.

Water at 20 °C will not disrupt the cell membrane.

Thus, the correct row is row 3 (Option E)

Correct Answer: A) 1, 2, and 4 only

An amino acid has an alpha carbon attached to an amino group, a carboxyl group, a hydrogen, and a side chain ‘R’.

Fatty acid has a carboxyl group and a long-chain hydrocarbon.

Glucose is a 6-carbon carbohydrate monomer. It contains 5 hydroxyl groups and an aldehyde group (-CHO).

Glycerol is a 3-carbon molecule that contains 3 hydroxyl groups, so it is a triol alcohol.

Thus, rows 1, 2, and 4 are correct.

Correct Answer: D) 1 only

When a sarcomere contracts, both the H-zone and I-band shorten while the A-band is unchanged.

During muscle contraction, the sarcomere shortens as the Z-lines (Z-discs) move closer together.

The I-band (region with only thin filaments) shortens, and the H-zone (region with only thick filaments) narrows or disappears. The A-band (length of thick filaments) remains unchanged because the thick filaments do not change length. The M-line (center of the sarcomere, where thick filaments are anchored) remains in place, but overall, the sarcomere shrinks in length.

Thin filaments (actin) slide over thick filaments (myosin) without either filament changing in size, causing the entire muscle to contract through the sliding filament mechanism.

A document has been prepared to include the images and diagrams related to the questions, placed directly below the worked solutions for clarity and reference.

Correct Answer: E) None of them

Label 1 – Bowman’s capsule: This is the site of ultrafiltration where blood plasma, including urea, is filtered by the glomerulus into the nephron. Large molecules like proteins are retained, but urea freely passes into the filtrate.

Label 2 – Descending limb of the loop of Henle: Water is reabsorbed by osmosis due to the surrounding high osmolarity of the medulla. However, solutes like urea are not reabsorbed here, so urea concentration in the filtrate increases as water leaves.

Label 3 – Distal convoluted tubule: This segment reabsorbs water and salts under hormonal regulation (like aldosterone), but it does not significantly reabsorb urea. Urea remains concentrated in the filtrate as volume decreases.

Label 4 – Collecting duct: Water reabsorption continues here, largely under the influence of antidiuretic hormone (ADH). Although water is removed, urea remains and diffuses out in the lower parts of the duct to help maintain the osmotic gradient in the medulla.

Correct Answer: E) 1, 2, and 3

In plants, cells in the leaves contain both mitochondria (for cellular respiration) and chloroplasts (for photosynthesis). CO2 is produced by the mitochondria at any time of the day, and it can be used by the plant for photosynthesis. Thus, all 3 mentioned statements are correct.

Correct Answer: C) A restriction enzyme causes phosphodiester bonds to be broken.

Option A: Incorrect. Ligase enzymes act as molecular glues by joining two DNA fragments through the formation of phosphodiester bonds between the sugar-phosphate backbones. They do not form hydrogen bonds, which are instead responsible for the base pairing between complementary nucleotides.

Option B: Incorrect. Restriction enzymes act as molecular scissors. They recognize specific DNA sequences (restriction sites) and cut the DNA at or near those sites, breaking phosphodiester bonds, not hydrogen bonds.

Option C: This is a correct statement. A restriction enzyme cuts DNA by breaking the phosphodiester bonds in the sugar-phosphate backbone at specific recognition sites.

Option D: Incorrect. Ligase enzymes form phosphodiester bonds between DNA fragments; they do not break them.

Option E: Incorrect. Restriction enzymes break phosphodiester bonds in the DNA backbone at specific recognition sites.

Correct Answer: E) 1024

Correct Answer: C) In active tissues where the carbon dioxide concentration is high, Hemoglobin has a low affinity for oxygen.

Option A: Incorrect. Increasing oxygen partial pressure increases hemoglobin’s affinity for oxygen, making it less likely to release oxygen, not more. Oxygen partial pressure (pO₂) affects hemoglobin’s affinity for oxygen. At high pO₂ (lungs), hemoglobin binds oxygen tightly; at low pO₂ (tissues), its affinity decreases, promoting oxygen release. This relationship is key to efficient oxygen transport.

Option B: Incorrect. In aerobic respiration, glucose is broken down in the presence of oxygen to produce carbon dioxide (CO₂), water, and ATP. The CO₂ released dissolves in blood and reacts with water to form carbonic acid, which quickly dissociates into hydrogen carbonate ions (HCO₃⁻) — an important way CO₂ is transported in the blood. Lactic acid is not produced in significant amounts during aerobic respiration; it mainly forms during anaerobic respiration when oxygen is lacking, such as during intense exercise. Thus, aerobic respiration leads to hydrogen carbonate ion formation but not to lactic acid accumulation.

Option C: This is a correct statement. The Bohr effect describes how high carbon dioxide levels and low pH in active tissues lower hemoglobin’s affinity for oxygen, helping release oxygen where it’s needed most.

Option D: Incorrect. While some CO2 is transported as carbaminohemoglobin, the majority is transported as bicarbonate ions (not carbaminohemoglobin)

Option E: Myoglobin has a higher affinity for oxygen than hemoglobin, meaning it is more saturated at lower oxygen partial pressures. Myoglobin is a small, oxygen-binding protein found mainly in muscle tissue. It stores and releases oxygen to muscle cells, especially during periods of high metabolic demand. Structurally, myoglobin consists of a single polypeptide chain and a heme group that binds oxygen. Unlike hemoglobin, which transports oxygen in the blood and has four subunits, myoglobin has only one subunit and binds oxygen more tightly. It is crucial for maintaining oxygen supply during intense muscular activity and provides muscles with a readily available oxygen reserve.

Correct Answer: E) 1, 2, 3, and 4

Process 1 - Muscle contraction: Involves calcium ions (Ca²⁺), which trigger the interaction between actin and myosin filaments, leading to contraction.
Process 2 - Nerve impulse transmission across a synapse: Relies on sodium (Na⁺) and potassium (K⁺) ions to generate action potentials, and calcium ions (Ca²⁺) to stimulate neurotransmitter release at synaptic terminals.
Process 3 - Photosynthesis: Uses hydrogen ions (H⁺) to create a proton gradient across the thylakoid membrane, driving ATP synthesis during the light-dependent reactions.
Process 4 - Oxidative phosphorylation: Involves the movement of hydrogen ions (H⁺) across the inner mitochondrial membrane to form a proton gradient, essential for ATP production.

Thus, the processes that involve ions are 1, 2, 3, and 4.

Correct Answer: C) 3 only

When sugar is added to ice, the sugar molecules interfere with the orderly arrangement of water molecules in the ice lattice. This disruption lowers the melting point (also called freezing point depression). As a result, the mixture now melts at a lower temperature than pure ice.
● Statement 1 is incorrect: Sugar does not directly give energy to the water molecules.
● Statement 2 is incorrect: the melting point becomes lower, not higher.
● Statement 3 is correct: the melting point is lowered, explaining why the ice melted even though the temperature remained at –1 °C.

Correct Answer: A) 3 only

To identify a redox reaction, we need to check the oxidation number changes between reactants and products in a reaction.

1. 4LiH + AlCl₃ → 3LiCl + LiAlH₄
LiH : Li (+1), H (-1)
AlCl₃: Al (+3), Cl (-1)
LiCl : Li (+1), Cl (-1)
LiAlH₄: Li (+1), Al (+3), H (-1)
The oxidation number of each species does not change. This is not a redox reaction.

2. N₂O₃ + 3H₂O → 2H₃O+ + 2NO₂–
N₂O₃: N (+3), O (-2)
H₂O: H (+1), O (-2)
H₃O+: H (+1), O (-2)
NO₂– : N ((+3), O (-2)

The oxidation number of each species does not change. This is not a redox reaction.

3. NH₄NO₃ → 2H₂O + N₂O
N in NH₄⁺ = –3, N in NO₃⁻ = +5
H₂O: H is +1, O is –2
N in N₂O = +1
Nitrogen in NH₄⁺ (–3) is oxidized to N₂O (+1). Nitrogen in NO₃⁻ (+5) is reduced to N₂O (+1). This is a redox reaction.