Test Invite Exam

Section 1: Biology

Question 1: In which phase of the mitosis the sister chromatids are separated?

• Anaphase
• Telophase
• Prophase
• Metaphase

Anaphase is the specific stage of mitosis dedicated to the equal distribution of genetic material between two new cells. During this phase, the centromeres that held the identical sister chromatids together dissolve, and the individual chromosomes are pulled toward opposite poles of the cell by the shortening of the spindle fibers. This precise separation ensures that each daughter cell will eventually possess a complete and identical set of genetic information.

Question 2: Coffee and especially its content "caffeine" is widely ingested to prevent drowsiness and improving performance. Due to which mechanism does that occur?

• Blocking the receptors of adenosine.
• Activating nerve and pain receptors in the pharynx.
• Raising the blood sugar level by stimulating the vestigial system.
• Increasing the blood flow by enhancing the fluidity of the blood.

Caffeine primarily improves alertness by acting as a competitive antagonist, blocking adenosine receptors in the central nervous system. Adenosine is a neuromodulator that builds up in the brain during waking hours, binding to receptors to signal fatigue and promote sleepiness. Because caffeine has a similar molecular structure, it occupies these receptor sites without activating them, thereby preventing the "sleep signal" from being received and resulting in increased neural activity and focus.

Question 3: A patient needs a blood donation and has the blood group AB Rh+. Which blood group can be donated?

• Only AB Rh+ and AB Rh-
• All
• Only AB Rh+
• Only AB Rh+, B Rh+, B Rh- and O Rh+

An individual with the blood group AB Rh+ is considered the "universal recipient." This is because their immune system has been "educated" to recognize A, B, and Rh antigens, meaning their plasma contains no antibodies against any of these factors. Consequently, they can safely receive a transfusion of all blood types (A, B, AB, and O, whether Rh+ or Rh-) without triggering a life-threatening hemolytic transfusion reaction.

Question 4: When working with MRI (magnetic resonance imaging), on which element, present in the human body, is the imaging based?

• Hydrogen
• Mercury
• Uranium
• Lead

MRI technology primarily utilizes hydrogen atoms (specifically the protons) because they are exceptionally abundant in the human body, found in nearly every water and fat molecule. When a patient is placed inside the strong magnetic field of an MRI scanner, these hydrogen protons align with the field; the machine then uses radiofrequency pulses to disrupt this alignment, and as the protons "relax" back to their original state, they emit signals that are processed to create high-resolution images of internal anatomy.

Question 5: Which of the terms below does not describe a primary mutagen?

• Ethanol
• Ultraviolet radiation
• X-rays
• Aflatoxins

While ethanol consumption is associated with an increased risk of several cancers, it is not classified as a primary mutagen. A primary mutagen is a physical or chemical agent that directly interacts with the DNA molecule to cause permanent structural damage or sequence changes. In contrast, ethanol acts as a carcinogen primarily through secondary mechanisms, such as its metabolism into acetaldehyde (which is toxic), the induction of chronic inflammation, and the production of reactive oxygen species that damage cellular components over time.

Question 6: Which of the following statements is not true?

• The cell is the smallest unit of life.
• A biological membrane serves as a border between individual cells.
• All cells of a human body are of a similar size.
• A cell mostly consists of water.

The statement that all human cells are of a similar size is false because cell morphology varies dramatically to accommodate highly specialized functions. For example, a mature red blood cell is a tiny, biconcave disc roughly 7–8 micrometers in diameter, whereas a single motor neuron can have an axon extending over a meter in length. This vast diversity in size and shape—ranging from the microscopic sperm cell to the relatively massive human egg cell (ovum)—is a fundamental characteristic of human physiology.

Question 7: Which acid is naturally found in various foods and is essential for the human body? This acid is also referred to as a vitamin.

• Sulphuric acid
• Hydrochloric acid
• Sodium Hydroxide
• Ascorbic acid

Ascorbic acid, widely recognized as Vitamin C, is a vital water-soluble nutrient found abundantly in citrus fruits and leafy vegetables. It is essential for human health because it acts as a potent antioxidant, protecting cells from oxidative stress. Furthermore, it plays a critical role in the synthesis of collagen, which is necessary for the maintenance of healthy skin, blood vessels, and connective tissues, and it is a key supporter of the overall immune system.

Question 8: Which substance can only be transported in the blood bound to proteins?

• Insulin
• Cholesterol
• Vitamins
• Glucose

Cholesterol is a type of lipid, making it inherently hydrophobic; this means it cannot dissolve in the water-based environment of the blood plasma. To be transported efficiently to tissues throughout the body, it must be encapsulated within specialized particles known as lipoproteins. These structures consist of an internal core of hydrophobic lipids surrounded by an outer layer of proteins (apolipoproteins) and phospholipids, which allow them to remain soluble in the bloodstream.

Question 9: Which of the following organs of the human body is able to regenerate itself?

• Kidney
• Pancreas
• Liver
• Spleen

The liver possesses a remarkable and unique ability among human internal organs to undergo compensatory hyperplasia, effectively regenerating its mass after injury or surgical removal. Even if up to 75% of the liver is removed, the remaining healthy hepatocytes can rapidly re-enter the cell cycle and divide until the organ returns to its original size and regains full functional capacity. This robust regenerative capacity is essential for maintaining the body’s metabolic balance and detoxification processes.

Question 10: Which statement about blood platelets (thrombocytes) is false?

• They are formed in the spleen.
• They have a lifespan of a few days.
• They are the smallest blood cells.
• Their importance lies in hemostasis and blood coagulation.

The false statement is that platelets are formed in the spleen. In reality, blood platelets are produced in the red bone marrow through the fragmentation of large precursor cells called megakaryocytes. While the spleen serves as a significant reservoir, storing approximately one-third of the body's platelets at any given time, it is not the site of their primary formation.

Question 11: What's the reaction speed temperature dependence?

• If the temperature is reduced by 20 K, the yield is increased by one eighth.
• If the temperature is increased by 10 K, the yield doubles or multiples.
• If the temperature is reduced by 20 K, the yield is reduced by 50%.
• If the temperature is increased by 10 K, the yield is reduced by one third.

This question refers to the van't Hoff rule (or the Q10Q10​ rule), which states that for most biochemical and chemical reactions, an increase in temperature of 10 Kelvin (or 10°Celsius) roughly doubles or triples the reaction rate. This occurs because the increased thermal energy provides more molecules with the kinetic energy required to overcome the activation energy barrier, leading to more frequent and effective collisions between reactants.

Question 12: A DNA strand consists of 17% of the nucleobase thymine. What percentage in that strand does the nucleobase cytosine account for?

• 25%
• 33%
• 50%
• 75%
• This cannot be calculated based on the provided information.

According to Chargaff's rule, in a double-stranded DNA molecule, the amount of adenine (A) always equals thymine (T), and the amount of guanine (G) always equals cytosine (C). If T is 17%, then A must also be 17%, totaling 34% for the A-T pairs. This leaves 66% of the strand to be composed of G-C pairs; dividing this remainder by two gives the percentage for cytosine as 33%.

Question 13: Which statement about chloroplasts is not true?

• Chloroplasts are found in plants and algae.
• Chloroplasts are organelles responsible for photosynthesis.
• Chloroplasts are cells who are responsible for producing organic material from carbon dioxide, water and light.
• Chloroplasts are similar to the mitochondria.

The statement that chloroplasts are "cells" is fundamentally incorrect; they are membrane-bound organelles found within the cells of plants and algae. While they are responsible for photosynthesis and share evolutionary similarities with mitochondria—such as having their own DNA and a double membrane—they are sub-cellular structures and do not function as independent living organisms.

Question 14: Where is the pylorus located in the human digestive tract?

• Transition of the esophagus into the stomach.
• Transition from the small intestine to the large intestine.
• Transition from the stomach to the duodenum.
• Transition from the large intestine to the rectum.

The pylorus is the distal region of the stomach that acts as a gateway to the small intestine. It consists of the pyloric antrum and the pyloric canal, ending at the pyloric sphincter, which regulates the transition of partially digested food (chyme) from the stomach into the duodenum. This valve ensures that digestion proceeds at an appropriate pace and prevents the reflux of intestinal contents back into the stomach.

Question 15: What percentage of the father's ribbon pattern of the genes must match that of the child for him to be his father?

• 50%
• 25%
• 75%
• 100%

In the context of DNA fragment analysis for paternity testing, the "ribbon pattern" refers to the specific bands generated during gel electrophoresis. Since a child inherits exactly half of their nuclear DNA from their biological father, every single one of the child's paternal alleles (or "bands") must be present in the father's genetic profile. Therefore, there must be a 100% match between the child's paternal-origin bands and the corresponding bands in the father's pattern to confirm biological parentage.

Question 16: Penicillin is an important antibiotic which is derived from...?

• Bacteria
• Fungi
• Mice
• Algae

Penicillin, the first mass-produced antibiotic, is derived from fungi of the genus Penicillium (specifically Penicillium chrysogenum). Discovered by Alexander Fleming in 1928, this naturally occurring compound works by interfering with the synthesis of peptidoglycan in bacterial cell walls, ultimately causing the bacteria to rupture and die.

Question 17: Which part of the ear influences the balance?

• The semi-circular canals.
• The lobe.
• The anvil.
• The ulnar nerve.

The semi-circular canals, located in the inner ear as part of the vestibular system, are the primary structures responsible for maintaining dynamic equilibrium and balance. These three fluid-filled loops are oriented in different planes to detect rotational movements of the head; as the head moves, the shifting fluid (endolymph) stimulates sensory hair cells that send signals to the brain to coordinate spatial orientation and posture.

Question 18 (Page 6): The Golgi apparatus... which statement is not true?

• The entirety of the dictyosomes of a cell is called the Golgi complex.
• The Golgi apparatus is used for the conversion, sorting and packaging of substances.
• The Golgi apparatus is only found in the spleen.
• Lysosomes contain digestive enzymes.

The statement that the Golgi apparatus is "only found in the spleen" is false. The Golgi apparatus is a fundamental membrane-bound organelle found in nearly all eukaryotic cells, including those of animals, plants, and fungi. Its universal presence is essential for biological function, as it acts as the cell's "post office," receiving proteins and lipids from the endoplasmic reticulum to be modified, sorted, and packaged into vesicles for transport to their final destinations.

Question 19: Which of the following statements does not apply to the skin?

• The physiological pH-value of the skin is 4.
• Nerve endings extend into the epidermis.
• Heat and cold corpuscles in the dermis react to temperature changes.
• There are many sensory cells in the skin of the foot sole.

While the skin surface is naturally acidic to inhibit the growth of harmful pathogens, a pH value of 4 is generally considered too low to be the standard physiological average. The "acid mantle" of healthy human skin typically ranges between a pH of 4.7 and 5.7; therefore, a fixed value of 4 is inaccurate compared to the other established anatomical facts provided about nerve distribution, thermoreception, and sensory density.

Question 20: What is, according to its definition, a 'Bacteriophage'?

• An organism feeding on Viruses.
• A virus targeting bacteria.
• A virus - bacteria symbiosis.
• A bacterium that targets fungi.

A bacteriophage (often simply called a "phage") is a specific type of virus that infects and replicates within bacteria. Phages are composed of a nucleic acid core (either DNA or RNA) encased in a protein coat; they attach to the surface of a target bacterium, inject their genetic material, and hijack the host's cellular machinery to produce new viral particles, often resulting in the death of the bacterial cell.

Question 21: The first living organisms on earth obtained their energy from:

• The sun.
• Consuming other dead organisms.
• Consuming each other.
• Consuming organic molecules.

According to the heterotroph hypothesis, the earliest life forms on Earth were simple, single-celled organisms that lived in an environment rich in non-biologically produced organic compounds. These primitive organisms obtained their energy by consuming and fermenting these organic molecules (such as sugars and amino acids) from the surrounding "primordial soup," predating the evolution of complex processes like photosynthesis or active predation.

Question 22: Composition of the body. Calcium is important for the structure of bones and teeth. But how much of the overall calcium of a human body is stored within bones and teeth?

• 10%
• 25%
• 50%
• 99%

Approximately 99% of the total calcium in the human body is stored in the skeletal system and the teeth, primarily in the form of a hard mineral called hydroxyapatite. The remaining 1% is found in the blood, extracellular fluid, and soft tissues, where it plays a vital role in essential physiological functions such as blood clotting, muscle contraction, and nerve impulse transmission.

Question 23: Which is true for the saliva of an average healthy human adult?

• It is slightly alkaline.
• It is highly acidic.
• It is slightly saline.
• It is highly alkaline.

Human saliva is composed of approximately 99.5% water, with the remaining 0.5% consisting of electrolytes, mucus, white blood cells, and enzymes. Because it contains dissolved electrolytes like sodium chloride (NaClNaCl), it is accurately described as being slightly saline. While its pH is generally near neutral (6.2 to 7.6), its electrolyte content is its most consistent chemical characteristic alongside its digestive and protective roles.

Question 24: What is the "normal" level of blood pressure in an average adult?

• 90 / 110 mm HG.
• 150 / 60 mm HG.
• 120 / 80 mm HG.
• 70 / 110 mm HG.

For a healthy human adult, a blood pressure reading of 120/80 mmHg is considered the standard "normal" range. The first number (systolic) represents the pressure in the arteries when the heart beats, and the second number (diastolic) represents the pressure when the heart rests between beats. Maintaining pressure near this level is crucial for ensuring adequate oxygen delivery to tissues without overstressing the cardiovascular system.

Question 25: Which part of the cell is considered as the "power plant"?

• The nucleus.
• The Golgi.
• The mitochondria.
• The cytoplasm.

The mitochondria are universally known as the "power plants" of the cell because they are the site of aerobic cellular respiration. Within these organelles, nutrients like glucose are broken down in the presence of oxygen to produce Adenosine Triphosphate (ATP), which is the primary energy currency used by the cell to perform all its vital biological tasks.

Question 26: According to Charles Darwin, which of the following statements regarding the formation and alteration of biological units does not apply?

• Living organisms produce more offspring than are necessary to conserve the species.
• Individuals of a population can differ in considerable characteristics.
• Overpopulation and limited resources lead to a struggle for existence.
• Only the strongest and most potent individuals survive and pass on their genetic material.

The statement that "only the strongest and most potent" survive is a common misunderstanding that does not accurately reflect Darwin's theory of natural selection. Darwinian "fitness" is not about physical strength or potency, but rather about an organism's relative ability to survive and reproduce in its specific environment. Often, it is the individuals who are most cooperative, efficient at gathering resources, or simply better camouflaged that survive to pass on their genes, regardless of their physical "strength."

Question 27: Which of the following cell organelles a prokaryote does not have?

• Cytoplasm.
• Plasmid.
• Ribosomes.
• Golgi apparatus.

Prokaryotes (such as bacteria) are characterized by their lack of membrane-bound internal structures. While they do possess cytoplasm, ribosomes for protein synthesis, and often small circular DNA molecules called plasmids, they do not have a Golgi apparatus, nucleus, or mitochondria. The absence of these specialized organelles distinguishes the simpler prokaryotic cell structure from the more complex eukaryotic cells found in plants and animals.

Question 28: Which statement on DNA and RNA is correct?

• Both contain the nucleic acid bases adenine, guanine and cytosine.
• Both can only be found in the cell nucleus.
• Both are of a double helix structure.
• Only DNA has a sugar-phosphate backbone.

DNA and RNA share several fundamental chemical similarities, most notably that they both utilize the nitrogenous bases Adenine (A), Guanine (G), and Cytosine (C). They differ in their fourth base (DNA uses Thymine, while RNA uses Uracil), their sugar component (deoxyribose vs. ribose), and their typical structure (DNA is a double helix, whereas RNA is usually single-stranded).

Question 29: A person with albinism is homozygous for the recessive allele that controls the synthesis of melanin. A normally pigmented couple has a child with albinism. How high is the probability that the couple's next child will not be albino?

• 50%
• 25%
• 0%
• 75%

If a normally pigmented couple has a child with albinism (a recessive trait, 

aaaa), both parents must be heterozygous carriers (AaAa). According to Mendelian genetics, a cross between two carriers (Aa×AaAa×Aa) results in a 25% chance of an albino child (aaaa) and a 75% chance of a normally pigmented child (comprising a 25% chance of AAAA and a 50% chance of AaAa). Each birth is an independent event, meaning the probability remains the same for every subsequent child.

Question 30: Which statement about hormones is false?

• Hormones can be stored.
• Hormones always consist of amino acids.
• Hormones are also called semi-chemicals.
• The hormone estrogen is synthesized in the ovaries.

The statement that hormones "always consist of amino acids" is false because hormones are chemically diverse. While many hormones (like insulin) are peptides or proteins made of amino acids, another major class consists of steroid hormones (such as estrogen, testosterone, and cortisol), which are lipids derived from cholesterol. Therefore, the presence of non-amino-acid-based hormones makes the "always" in the statement incorrect.

Section 2: Chemistry

Question 1 (Page 1): What are the results when corresponding quantities of an equal molar ratio of hydrochloric acid and a solution of sodium hydroxide are reacting with each other?

• Water (pH=7) + table salt + heat.
• Water (pH>7) + chlorine gas + ice.
• Water (pH<7) + carbon dioxide + table salt.
• None of the above.

This reaction is a classic example of acid-base neutralization between a strong acid (HCl) and a strong base (NaOH). When they react in an equal molar ratio, the hydrogen ions (H+H+) and hydroxide ions (OH−OH−) combine to form pure, neutral water with a pH of 7. Simultaneously, the remaining sodium (Na+Na+) and chloride (Cl−Cl−) ions form sodium chloride (table salt), and the reaction releases energy into the environment in the form of heat.

Question 2 (Page 1): Organic compounds are the basis of life. What are the four basic elements of these compounds?

• C, H, O and N.
• C, H, O and P.
• C, H, O and Cl.
• C, H, O and Na.

The four elements Carbon (C), Hydrogen (H), Oxygen (O), and Nitrogen (N) are the essential building blocks for virtually all organic matter on Earth. Their unique bonding properties allow them to form the complex backbones and functional groups of proteins, lipids, carbohydrates, and nucleic acids. Together, these four elements make up approximately 96% of the human body's total mass.

Question 3 (Page 1): Which of the following statements can always be considered true regarding an exothermic reaction (as opposed to an endothermic reaction)?

• It is faster than an endothermic reaction.
• It reduces the entropy of the universe.
• It is the result of bond formation.
• It releases energy in the form of heat.

An exothermic reaction is defined by its thermodynamics: the energy required to break the bonds in the reactants is less than the energy released when new bonds are formed in the products. This net surplus of energy is released into the surroundings, most frequently as thermal energy (heat). This distinguishes it from endothermic reactions, which must absorb energy from their surroundings to proceed.

Question 4 (Page 2): With which change of state is it not possible to denature a protein?

• Temperature increase.
• pH value shift into the acidic.
• pH value shift into the alkaline.
• None of the above.

Protein denaturation occurs when the weak chemical interactions—such as hydrogen bonds and disulfide bridges—that maintain a protein's specific three-dimensional shape are disrupted. High temperatures, extremely low pH (acidic), and extremely high pH (alkaline) are all highly effective at breaking these bonds and causing the protein to unfold and lose its function. Therefore, none of the above options can be considered "safe" changes that would avoid denaturation.

Question 5 (Page 2): Calcium is in the second group and in the fourth row of the periodic table of the elements. To which family of elements does it belong?

• Alkali metals.
• Noble gases.
• Alkaline earth metals.
• Halogens.

Elements located in Group 2 of the periodic table are collectively referred to as the alkaline earth metals. This family, which includes calcium, magnesium, and strontium, is characterized by having two electrons in their outermost shell, a distinct metallic luster, and a high level of chemical reactivity. They are typically found in nature as compounds rather than pure elements due to their tendency to lose those two outer electrons to reach a stable state.

Question 6 (Page 2): In a balanced state, the amount of substances in acetic acid and ethanol is 1 mol each and in ethyl acetic ester and water 2 mol each. [...] Calculate the equilibrium constant of the chemical reaction.

• The equilibrium constant is 4.
• The equilibrium constant is 10.
• The equilibrium constant is 0.5.
• The equation cannot be solved in this way.

The equilibrium constant (KeqKeq​) for a reaction is calculated by dividing the product of the concentrations of the products by the product of the concentrations of the reactants. Using the values provided in the prompt—2 moles each for the products (ethyl acetate and water) and 1 mole each for the reactants (acetic acid and ethanol)—the equation is (2×2)/(1×1)(2×2)/(1×1), which yields an equilibrium constant of 4.

Question 7 (Page 3): What happens when a secondary alcohol is oxidized?

• Carboxylic acid + Water.
• Aldehyde + acid.
• Ketone + Water.
• None of the above.

When a secondary alcohol undergoes oxidation, the process involves the removal of two hydrogen atoms: one from the hydroxyl (-OH) group and one from the carbon atom to which it is attached. This results in the formation of a carbon-oxygen double bond in the interior of the carbon chain, creating a ketone and producing a molecule of water as a byproduct. Unlike primary alcohols, secondary alcohols cannot be oxidized further into carboxylic acids under standard conditions.

Question 8 (Page 3): Which among the following is the most important characteristic of Noble metals?

• Luster.
• Non-reactive Nature.
• Preciousness.
• Rare availability.

The defining characteristic of noble metals, such as gold, platinum, and palladium, is their exceptional non-reactive nature. Unlike base metals, noble metals are highly resistant to oxidation and corrosion, even when exposed to moisture, air, or strong acids. This chemical stability makes them highly desirable for use in jewelry, precision electronics, and medical devices where long-term durability is critical.

Question 9 (Page 3): Cellulose is an essential component of many plant cells. What does it consist of?

• Monosaccharide.
• Polysaccharide.
• Lipid.
• Polypeptide.

Cellulose is a complex carbohydrate that serves as the primary structural material in plant cell walls. It is a polysaccharide consisting of long, unbranched chains of thousands of β(1→4)β(1→4) linked D-glucose units. These long fibers provide plants with the tensile strength and rigidity needed to grow upright and withstand internal water pressure.

Question 10 (Page 4): What is the most effective way to condense a gas into a liquid?

• Maintain the temperature and increase the pressure.
• Increase the temperature and increase the pressure.
• Reduce the temperature and increase the pressure.
• Maintain the temperature and decrease the pressure.

Condensation is the phase transition from a gaseous state to a liquid state, which requires bringing molecules closer together and reducing their kinetic energy. By reducing the temperature, the kinetic energy of the gas particles decreases, allowing attractive intermolecular forces to take hold. Simultaneously, increasing the pressure physically forces the molecules into a smaller volume, facilitating the formation of the liquid phase.

Question 11 (Page 4): An ionic bond can be formed between which of the following pairs of atoms?

• Nitrogen and Oxygen.
• Oxygen and Helium.
• Carbon with itself.
• Calcium and Chlorine.

Ionic bonds typically occur between a metal and a non-metal with significantly different electronegativities. Calcium, a metal from the alkaline earth group, readily donates two electrons to become a Ca2+Ca2+ cation, while Chlorine, a halogen non-metal, readily accepts an electron to become a Cl−Cl− anion. The strong electrostatic attraction between these oppositely charged ions results in a stable ionic bond. In contrast, the other pairs form covalent bonds or involve inert gases that do not readily bond.

Question 12 (Page 4): Which among the following is the main constituent of vegetable oil and animal fats?

• Glycogen
• Galactose
• Triglyceride
• Diglyceride

Triglycerides are the primary storage form of energy in both plants and animals, making them the main component of oils and fats. Chemically, they are esters formed from one molecule of glycerol and three fatty acid chains. The physical state of the lipid—whether it is a liquid oil or a solid fat at room temperature—is determined by the length and degree of saturation of these specific fatty acid chains.

Question 13 (Page 5): Which of the following liquids can be mixed without phase boundaries?

• Hexane and benzene.
• Water and oil.
• Octane and water.
• Sodium chloride solution and decane.

According to the chemical principle "like dissolves like," substances with similar polarities are miscible. Hexane and benzene are both non-polar organic hydrocarbons, allowing them to intermix completely at the molecular level without forming a visible phase boundary. Conversely, polar liquids like water will not mix with non-polar substances like oil, octane, or decane, resulting in distinct layers.

Question 14 (Page 5): The following chemical elements shall be sorted by increasing atomic number / mass (ascending from left to right): Oxygen (=O), Carbon (=C), Iodine (=I), Magnesium (=Mg), Lead (=Pb), Hydrogen (=H).

• I < Mg < Pb < O < C < H.
• H < C < O < Mg < I < Pb.
• H < Mg < O < Pb < C < I.
• Mg < I < H < O < C < Pb.

Sorting elements by atomic number—the number of protons in the nucleus—is the standard method for arranging the periodic table. The atomic numbers for this set are: Hydrogen (1), Carbon (6), Oxygen (8), Magnesium (12), Iodine (53), and Lead (82). The sequence H < C < O < Mg < I < Pb correctly follows this increasing order of atomic complexity and mass.

Question 15 (Page 5): Trimethylxanthine is the chemical name of a stimulant which is found in prominent and popular beverages. What is the popular name?

• Adrenalin
• Endorphin
• Caffeine
• Ritalin

Caffeine is a naturally occurring alkaloid found in coffee, tea, and cocoa, and its systematic IUPAC name is 1,3,7-trimethylxanthine. It acts as a stimulant to the central nervous system by competitively inhibiting adenosine receptors in the brain, which prevents the onset of drowsiness and helps maintain alertness and cognitive performance.

Question 16 (Page 6): How many grams is the molar mass of glucose?

• 5 g
• 32 g
• 135 mg
• 180 g

The molecular formula for glucose is C6H12O6C6​H12​O6​. To calculate its molar mass, the atomic weights of its components must be summed: (6 Carbon atoms × 12.01 g/mol ) + (12 Hydrogen atoms × 1.01 g/mol ) + (6 Oxygen atoms × 16.00 g/mol ). This calculation totals approximately 180 grams per mole, meaning that one mole of glucose contains exactly that mass of the substance.

Question 17 (Page 6): 

SO2SO2​ is known for sure - What is the oxidation level of sulfur in a sulfur dioxide molecule?

•  
  • II.
•  
  • IV.
• + IV.
•  
  • II.

In a neutral molecule like sulfur dioxide (SO2SO2​), the sum of all oxidation states must equal zero. Oxygen typically has an oxidation state of -2; since there are two oxygen atoms, they contribute a total charge of -4. To balance this and keep the molecule neutral, the single sulfur atom must have an oxidation state of +4.

Question 18 (Page 6): Bonds between atoms and molecules can take different forms and have different strengths. Which is the weakest of the following interactions?

• Van der Waals forces.
• Metallic bond.
• Covalent bond.
• Hydrogen bond.

Van der Waals forces are the weakest type of intermolecular attraction, arising from temporary fluctuations in electron density that create transient dipoles. While essential for the condensation of non-polar gases, they are significantly weaker than hydrogen bonds (strong dipole-dipole attractions) and far weaker than intramolecular bonds like covalent or metallic bonds, which involve the actual sharing or pooling of electrons between atoms.

Question 19 (Page 7): As per Avogadro's hypothesis, equal volumes of different gases at the same temperature and pressure contain equal number of ...?

• Atoms
• Electrons
• Protons
• Molecules

Avogadro's Law is a fundamental gas law stating that under identical conditions of temperature and pressure, equal volumes of all gases contain an equal number of molecules. This principle implies that the volume occupied by a gas depends only on the amount of substance (moles) and the environmental conditions, rather than the chemical identity or size of the individual gas particles.

Question 20 (Page 7): Gargling with a solution of table salt is known to provide relief for a sore throat because... ?

• It works as analgesic.
• It dehydrates water from inflammatory tissues by Osmosis.
• It kills bacteria.
• Placebo effect.

Using a salt-water solution creates a hypertonic environment in the oral cavity. Through the biological process of osmosis, water is drawn out of the inflamed, swollen tissues of the throat and toward the higher concentration of salt. This physical removal of excess fluid reduces painful swelling and pressure, providing symptomatic relief for the individual.

Question 21 (Page 7): Which of these statements about the chemical equilibrium is wrong?

• Outward and backward reactions are equally fast.
• The equilibrium depends on pressure and temperature.
• A catalyst accelerates the equilibrium adjustment.
• In a state of equilibrium, no reaction takes place.

The statement that "no reaction takes place" is incorrect because chemical equilibrium is a dynamic, not static, state. In a system at equilibrium, the forward and reverse reactions continue to occur simultaneously at the exact same rate. Because the rates of production and consumption are equal, the net concentrations of the reactants and products remain constant, giving the appearance of no change even though molecular activity is ongoing.

Question 22 (Page 8): The following statements are made about a reaction: Under standard conditions the enthalpy of that reaction is -14 kJ/mol (exerting heat) and the entropy -2000 J/mol x K (activation energy). What kind of reaction is this?

• Exothermic, endergonic.
• No statement is possible.
• Endothermic, exergonic.
• Endothermic, endergonic.

A negative enthalpy (ΔH=−14ΔH=−14 kJ/mol) indicates that the reaction is exothermic, meaning it releases heat. To determine its spontaneity, we use the Gibbs Free Energy equation (ΔG=ΔH−TΔSΔG=ΔH−TΔS). With a large negative entropy (ΔS=−2000ΔS=−2000J/mol·K), the −TΔS−TΔS term becomes a very large positive value at standard temperatures, making ΔGΔG positive. A reaction with a positive ΔGΔG is classified as endergonic, meaning it is non-spontaneous and requires an input of work.

Question 23 (Page 8): Which of the following statements regarding redox reactions applies?

• Electrons are destroyed in redox processes.
• An oxidizing agent oxidizes another substance and is itself reduced in the process.
• Redox reactions are proton transfer reactions.
• The more positive a redox potential, the stronger the reduction power.

Redox reactions are defined by the simultaneous transfer of electrons between chemical species. An oxidizing agent is a substance that gains electrons by taking them from another substance (thereby oxidizing that substance). By accepting these electrons, the oxidizing agent undergoes reduction itself. Protons are transferred in acid-base chemistry, not redox, and energy is conserved in these processes, meaning electrons are never destroyed.

Question 24 (Page 8): Lysergic acid diethylamide (LSD) is a drug used as a ...?

• Steroid
• Hallucinogen
• Analgesia
• Sedative

LSD is a potent semi-synthetic psychedelic drug that primarily interacts with serotonin receptors in the brain to cause profound alterations in perception, mood, and cognitive processes. It is clinically classified as a hallucinogen because its primary effects include sensory distortions, such as visual patterns and auditory changes, and a fundamentally altered sense of time and space.

Question 25 (Page 9): Which of the following elements is an essential constituent of acids?

• Hydrogen
• Carbon
• Oxygen
• Fluoride

By most chemical definitions—including Arrhenius and Brønsted-Lowry—an acid is a substance capable of donating a hydrogen ion (H+H+), or proton, to another substance. While many acids contain oxygen (such as sulfuric acid) or halogens (such as hydrochloric acid), the presence of hydrogen is the universal requirement that allows these molecules to exhibit their characteristic acidic behavior.

Question 26 (Page 9): Which among the following is true about solubility of "Lipids"?

• They are water soluble but insoluble in organic solvents.
• They are soluble in water but soluble in organic solvents.
• They are insoluble in water as well as organic solvents.
• They are insoluble in water but soluble in organic solvents.

Lipids are a diverse group of organic molecules characterized by their non-polar, hydrophobic nature. Following the "like dissolves like" rule, lipids cannot form favorable interactions with polar water molecules, making them insoluble in water. However, they are highly soluble in non-polar organic solvents, such as ether or chloroform, which can effectively surround and dissolve the lipid molecules.

Question 27 (Page 9): Peptides are the basic substance for many different substances in the body. They are constructed from which biochemical units?

• Folic acid.
• Tocopherol.
• Amino acid.
• Vitamin K.

Peptides and proteins are biological polymers created through the linkage of amino acids. During protein synthesis, the carboxyl group of one amino acid reacts with the amino group of another to form a covalent peptide bond. These chains of amino acids then fold into complex three-dimensional shapes that perform a vast array of essential functions within the human body.

Question 28 (Page 10): Which among the following is an ionic solid?

• Glass
• Dry ice
• Table salt
• All are ionic solids

Table salt (sodium chloride, NaClNaCl) is the classic example of an ionic solid, consisting of a rigid, repeating three-dimensional crystalline lattice of sodium cations and chloride anions held together by strong electrostatic forces. Glass is an amorphous (non-crystalline) solid, and dry ice is a molecular solid composed of CO2CO2​ molecules held together by weak intermolecular attractions rather than ionic bonds.

Question 29 (Page 10): A galvanic cell reacts until...?

• The anode has dissolved.
• The charge exceeds 50mV.
• The liquid has evaporated.
• The current has expired.

A galvanic cell, such as a common battery, functions by converting chemical potential energy into electrical energy through spontaneous redox reactions. The cell will continue to generate a flow of electrons (electrical current) as long as there are reactants available. Once the reactants are consumed or the chemical system reaches equilibrium, the potential difference drops to zero, and the current expires.

Question 30 (Page 10): Gastric acid has a pH value of about 2. Looking at a neutral solution X with a pH value of 7, how can one describe the pH value of gastric acid?

• 2.5x more acidic than solution X.
• 10x more acidic than solution X.
• 14x more acidic than solution X.
• None of the answers given.

The pH scale is logarithmic, meaning that each whole number decrease in pH represents a ten-fold (101101) increase in acidity (concentration of H+H+ ions). Since the difference between neutral water (pH 7) and gastric acid (pH 2) is 5 units, the difference in acidity is 105105. Therefore, gastric acid is 100,000 times more acidic than a neutral solution. As this massive difference is not represented by the specific multipliers in the other choices, None of the answers given is the only correct response.

Section 3: Mathematics

Question 1 (Page 1): The derivative of f(x)=x3f(x)=x3  is:

• f′(x)=x2f′(x)=x2
• f′(x)=2xf′(x)=2x
• f′(x)=3x2f′(x)=3x2
• f′(x)=3xf′(x)=3x

To solve this, we use the power rule of differentiation, which states that for any function 

f(x)=xnf(x)=xn, its derivative is f′(x)=n⋅x(n−1)f′(x)=n⋅x(n−1). Applying this rule to 

x3x3, we multiply by the exponent (33) and then subtract one from the exponent (3−1=23−1=2), resulting in the correct derivative: 

3x23x2

.

Question 2 (Page 1): The derivative of a quadratic function is a:

• Line.
• Hyperbola.
• Parabola.
• Symmetrical Parabola.

A quadratic function is an equation of the second degree, typically written as 

ax2+bx+cax2+bx+c. When you calculate its derivative using the power rule, you obtain a first-degree equation in the form 2ax+b2ax+b. Because this result is a first-degree polynomial, it geometrically represents a straight line when plotted on a coordinate plane, showing that the rate of change of a parabola is linear.

Question 3 (Page 1): Decide whether there is linear or exponential growth/decrease. Susi is ill. She must take 4 mg of a medication daily from a certain day. 25% of the medication is broken down daily.

• Neither a decrease nor a growth.
• Linear decrease.
• Exponential decrease.
• Exponential growth.

In this scenario, a constant amount of medication is being added daily, while a percentage of the total is being removed. This results in the drug concentration gradually accumulating and approaching a specific steady-state limit. Because the amount of substance added is constant while the amount removed is proportional to the total present, the resulting curve follows the mathematical pattern of exponential growth towards an asymptote.

Question 4: Which statement is not true for all kinds of triangles?

• The sum of all interior angles is always 180°
• a2+b2=c2a2+b2=c2
• The surface can be calculated as 

A=0.5⋅b⋅hA=0.5⋅b⋅h

, whereas 

b=baseb=base

 and 

h=heighth=height

• (a/sin⁡α)=(b/sin⁡β)=(c/sin⁡γ)(a/sinα)=(b/sinβ)=(c/sinγ)

Explanation: The Pythagorean theorem (a2+b2=c2a2+b2=c2) is a specific property that holds true only for right-angled triangles. In contrast, the sum of interior angles, the standard area formula, and the Law of Sines are universal properties applicable to any triangle.

Question 5: In a primate reserve, the average age of male primates is 15 years and the average age of female primates is 19 years. Which of the following response options indicates the average age aa of the combined male and female primate population correctly?

• a=17a=17
• a<17a<17
• a>17a>17
• 15<a<1915<a<19

Explanation: The weighted average of a combined population must always lie between the minimum and maximum averages of the constituent subgroups. Since the two subgroup averages are 15 and 19, the overall average must be strictly greater than 15 and strictly less than 19, regardless of the population sizes.

Physics Section

Question 1: Materials become warmer when light is...?

• Absorbed
• Reflected
• Transmitted
• Light does not matter

Explanation: When a material absorbs light, the electromagnetic energy of the photons is converted into internal thermal energy. This increased internal energy causes the atoms and molecules in the material to vibrate more rapidly, resulting in a measurable increase in the material's temperature.

Question 2: The first law of thermodynamics is about...?

• Use of aerial up-drafts
• Conservation of energy
• Recycling of energy
• Energy loss in conversion from heat to kinetic energy

Explanation: The First Law of Thermodynamics is essentially a version of the Law of Conservation of Energy specifically adapted for thermodynamic systems. It states that energy cannot be created or destroyed in an isolated system; rather, it can only change forms or be transferred from one object to another.

Question 3: If the sun explodes, we would notice that in...?

• Immediately
• Less than 8 seconds
• App. 8 minutes
• More than 8 hours

Explanation: Light travels at a finite speed of approximately 299,792 kilometers per second. Given that the average distance from the Sun to the Earth is about 150 million kilometers, it takes approximately 8 minutes and 20 seconds for light (and any information about changes to the Sun) to reach our eyes.

Question 4: To express the average speed by an object which of the following is needed:

• Acceleration and velocity
• Velocity, distance and time
• Distance and time
• Velocity and distance

Explanation: Average speed is defined as a scalar quantity representing the total magnitude of movement over a period. It is calculated by taking the total distance traveled and dividing it by the total time taken to cover that distance (v=d/tv=d/t).

Question 5: What is the potential energy of an object?

• The electrical charge of the object
• The capacity of an object to store energy
• The energy of an object due to its position
• The kinetic energy which will be transferred after a crash

Explanation: Potential energy is "stored" energy that an object possesses specifically because of its position relative to other objects or its configuration within a field. For example, gravitational potential energy is determined by an object's height and mass within a gravitational field.

Question 6: If the sun explodes, we would notice that in ...?

• Immediately
• Less than 8 seconds
• App. 8 Minutes
• More than 8 hours

Explanation:
Light from the Sun takes approximately 8 minutes to travel the ~150 million km distance to Earth. Therefore, if the Sun suddenly exploded, we would not observe the event until the light (and any associated signals traveling at the speed of light) reached us—roughly 8 minutes later. Electromagnetic radiation cannot travel faster than light, so the observation is delayed by that transit time rather than being instantaneous or taking hours/days.

Question 7: To express the average speed by an object which of the following is needed:

• Acceleration and velocity
• Velocity, distance and time
• Distance and time
• Velocity and distance

Explanation: Average speed is defined as total distance traveled divided by total time taken (vavg=dtv_{avg} = \frac{d}{t}vavg​=td​). Only distance and time are required; velocity (a vector) and acceleration are not needed for the scalar quantity of average speed.

Question 8: What is the potential energy of an object?

• The electrical charge of the object
• The capacity of an object to store energy
• The energy of an object due to its position
• The kinetic energy which will be transferred after a crash

Explanation: Potential energy is the stored energy an object possesses because of its position or configuration in a force field (most commonly gravitational potential energy PE=mghPE = mghPE=mgh). It is distinct from kinetic energy, electrical charge, or a general “capacity to store energy.”

Section 4: General Knowledge

Question 1: What is Homer's famous Iliad about?

• Birth of Christ.
• The Trojan War.
• The Burning of Alexandria.
• The Sack of Constantinople.

The Iliad, attributed to the ancient Greek poet Homer, is an epic masterpiece that chronicles several significant weeks during the final year of the Trojan War. The narrative focuses on the internal conflict and the legendary "wrath" of the Greek hero Achilles, set against the backdrop of the massive siege of the city of Troy by the allied Greek states.

Question 2: What was the purpose of the Eiffel Tower?

• It was built for the 1889 World's Exhibition Fair in Paris.
• It was a present from the US government after the French revolution.
• It is a monument to celebrate 150th anniversary of the Storming of the Bastille.
• It is a prototype for a lighthouse.

The Eiffel Tower was originally constructed to serve as the centerpiece and grand entrance arch for the 1889 Exposition Universelle (World's Fair), held in Paris to celebrate the centennial of the French Revolution. Although it was initially intended to be a temporary structure that would be dismantled after 20 years, its use as a radiotelegraph station and its popularity with tourists ensured its survival as a permanent global icon.

Question 3: When did the storm on the Bastille happen in France?

• 14.07.1719.
• 14.07.1789.
• 14.07.1689.
• 14.07.1989.

The storming of the Bastille, a state prison and symbol of royal tyranny in Paris, occurred on July 14, 1789. This pivotal event saw a revolutionary mob successfully seize the fortress to gain control of its gunpowder and weapons; it is now commemorated annually as Bastille Day, marking a major turning point that ignited the French Revolution.

Question 4: What is the name of the smallest planet in our solar system?

• Earth
• Jupiter
• Europa
• Mercury

Explanation: Mercury is the smallest planet in our solar system, with a diameter of about 3,032 miles (4,879 kilometers), making it only slightly larger than Earth's Moon and significantly smaller than any other planet.

Question 5: Which country search has a "H" on the number plates of their cars?

• Helsinki
• Hungary
• Honduras
• Hamburg

Explanation: Within the European Union's vehicle registration system, the international identifying code for Hungary is "H." This letter is prominently displayed on the blue "EU strip" on the left side of Hungarian license plates.

Question 6: Which of the following European countries does not use the Euro as its currency?

• Austria
• Norway
• France
• Finland

Explanation: Norway is not a member of the European Union and maintains its own independent monetary system, using the Norwegian krone (NOK) as its official currency instead of the Euro.

Question 7: Where is the seat of the European Court of Justice (ECJ) located?

• Madrid
• London
• Luxembourg
• Berlin

Explanation: The European Court of Justice, which ensures that EU law is interpreted and applied consistently across all member states, is headquartered in Luxembourg City, Luxembourg.

Question 8: In which US city is Broadway located?

• New York City
• Chicago
• San Francisco
• Seattle

Explanation: Broadway is a famous thoroughfare in New York City, globally renowned as the heart of the American commercial theater industry and home to numerous historic performance venues.

Question 9: Which country has the most natural lakes?

• USA
• Canada
• Bolivia
• Spain

Explanation: Canada possesses the highest number of natural lakes in the world, containing approximately 60% of the Earth's lakes within its borders, totaling over two million throughout the country.

Question 10: What is the legislature in a political institution, such as a state or a city?

• The court that interprets laws and exerts power on behalf of a state or city.
• Independent mediating institutions such as political parties or labour unions.
• Consultative assemblies with the power to enact laws.
• None of the above answers.

Explanation: A legislature is a deliberative body of persons, usually elected, who are empowered to make, change, or repeal the laws of a country, state, or municipality.

Question 11: Which country was not directly affected by the Arab Spring?

• Egypt
• Libya
• Yemen
• Israel

Explanation: The Arab Spring was a series of anti-government protests, uprisings, and armed rebellions that spread across the Arab world in the early 2010s. Israel, not being an Arab nation, was not a participant in or a target of this specific geopolitical movement.

Question 12: What is the capital of Costa Rica?

• San José
• Cartago
• Cartago
• Asunción

Explanation: San José is the capital and largest city of Costa Rica. Located in the country's Central Valley, it serves as the hub for the nation's political, economic, and cultural activities.

Question 13: What set off the Thirty Years War during 17th Century?

• Rightful succession to the German Throne
• Religious dispute
• Bride kidnapping
• Colonial disputes in Southern Africa

Explanation: The Thirty Years' War (1618–1648) was initially sparked by a religious dispute between Protestant and Catholic states within the Holy Roman Empire, eventually escalating into one of the longest and most destructive conflicts in European history.

Question 14: On which continent is the longest river in the world located?

• South America
• Europe
• North America
• Australia

Explanation: While the Nile in Africa is traditionally cited, current scientific measurements often identify the Amazon River in South America as the longest river in the world, flowing over 4,000 miles from the Andes to the Atlantic.

Question 15: Who was Genghis Khan?

• Leader of the Mongol Empire
• Chinese philosopher and politician
• Chairman of the Communist Party of China
• Founder of the Han Dynasty

Explanation: Genghis Khan was the legendary founder and first Great Khan of the Mongol Empire. Under his leadership, the empire expanded rapidly through military conquest to become the largest contiguous land empire in history.

Question 16: Which country produces the most coffee in the world?

• Ecuador
• Ethiopia
• Brazil
• Uganda

Explanation: Brazil has been the world's leading producer of coffee for over 150 years, currently accounting for about a third of global production, largely due to its vast climate-suitable regions.

Question 17: What is measured with a hygrometer?

• Speed
• Temperature
• Humidity
• Sun Intensity

Explanation: A hygrometer is a scientific instrument designed to measure the amount of water vapor in the atmosphere, soil, or confined spaces, providing a reading of relative or absolute humidity.

Question 18: Who named the Pacific Ocean?

• Christopher Columbus
• Frédéric Chopin
• Ferdinand Magellan
• Douglass North

Explanation: The Portuguese explorer Ferdinand Magellan named the ocean "Mar Pacífico" (Peaceful Sea) in 1520 during his circumnavigation of the globe, as its waters were remarkably calm compared to the turbulent Atlantic and the Strait of Magellan.

Question 19: Which of the following cities is separated by a national border?

• Mitrovica
• Niagara Falls
• Berlin
• Nicosia

Explanation: Historically, Berlin was famously divided by a national border into East and West Berlin between 1949 and 1990, serving as a primary symbol of the Cold War division between the Soviet-aligned East and the Western Allies.

Question 20: When did the first European elections take place?

• 1990
• 1948
• 1979
• 1933

Explanation: The first direct, universal elections to the European Parliament were held in June 1979, marking a significant milestone in the democratic integration of the European Community.

Question 21: Which of the following cities did not lend its name to a treaty of the European Union?

• Maastricht
• Lisbon
• Nice
• Versailles

Explanation: While Maastricht, Lisbon, and Nice are all famous for hosting pivotal EU treaty signings, the Treaty of Versailles was a peace treaty that ended World War I and is unrelated to the organizational structure of the European Union.

Question 22: According to Tom L. Beauchamp and James F. Childress, what are the four principles of medical ethics?

• Self-determination, damage prevention, patient welfare and justice
• Protection, honesty, curiosity and knowledge
• Fairness, self-confidence, communication and perfectionism
• Fairness, consent, compliance and competence

Explanation: Beauchamp and Childress established the "four-principle" approach to bioethics, consisting of autonomy (self-determination), non-maleficence (damage prevention), beneficence (patient welfare), and justice.

Question 23: What is the smallest country in the world?

• Tuvalu
• Portugal
• Belgium
• Vatican City

Explanation: Vatican City is an independent city-state enclaved within Rome, Italy. With an area of only about 0.44 square kilometers (110 acres), it is recognized as the smallest sovereign state in the world by both area and population.

Question 24: In Norse mythology, Freyja is the goddess of...?

• love, fertility and death
• hunt, archery and resentment
• war, wine and wealth
• dance, disease and death

Explanation: Freyja is a prominent goddess in Norse mythology, ruling over matters of love, sex, beauty, and fertility, while also holding significant dominion over battle and the souls of the dead.

Question 25: Who was the first president of the United States?

• Abraham Lincoln
• Thomas Jefferson
• George Washington
• Theodore Roosevelt

Explanation: George Washington served as the first President of the United States from 1789 to 1797. He was a central figure in the nation's founding and was elected unanimously by the Electoral College.

Question 26: Which of the following metropolitan areas has the fewest inhabitants?

• New York
• London
• Lisbon
• Berlin-Brandenburg

Explanation: Among the listed options, Lisbon is the smallest metropolitan area by population. Major global hubs like New York and London, as well as the German capital region, have significantly higher density and total inhabitant counts.

Question 27: What is "cynophobia"?

• Fear of sharp objects
• Fear of dogs
• Fear of electricity
• Fear of height

Explanation: Cynophobia is a specific phobia characterized by an irrational and persistent fear of dogs. The term originates from the Greek words "kyon" (dog) and "phobos" (fear).

Question 28: What is the capital of Iceland?

• Reykjavik
• Bergen
• Tórshavn
• Tallinn

Explanation: Reykjavik is the capital and largest city of Iceland. Located on the coast of the Atlantic Ocean, it is the center of the country's government, economy, and culture.

Question 29: Who guards the gate to the underworld in the Greek mythology?

• Kerberos
• Gabriel
• Prometheus
• Neptun

Explanation: In Greek mythology, Cerberus (or Kerberos) is the multi-headed hound that guards the entrance to Hades, the underworld, to ensure that the souls of the dead do not escape and the living do not enter.

Question 30: Due to rumours, because of which of his inventions Alfred Nobel established the Nobel Prize?

• Electricity
• Explosives
• Automobile
• Uranium

Explanation: Alfred Nobel, the inventor of dynamite, established the Nobel Prizes in his will to honor humanitarian and scientific achievements. He was reportedly moved to do so after reading a premature obituary that branded him as the "merchant of death" for his work with powerful explosives