KMU MDCAT 2023 past paper, Code B

Answer: B. Necrosis

Necrosis is the term for cell death that occurs as a result of injury or damage to the tissue. Apoptosis, while also cell death, is a programmed, regulated process. Cancer and metastasis are related to uncontrolled cell growth and spread, not cell death due to damage.

Answer: D. Tobacco mosaic virus

The Tobacco Mosaic Virus (TMV) is famously known for its rod-like or helical structure. While bacteriophages have complex shapes and herpes viruses are icosahedral, TMV's morphology is consistently described as rod-shaped.

Answer: A. Heat of vaporization

The correct answer is A because the heat required to change the state of a substance, like converting water into vapor at its boiling point, is defined as its heat of vaporization. Option B is incorrect as specific heat capacity refers to the heat needed to raise the temperature of a substance, not change its state.

Answer: B. Protists

Parazoa, like sponges, are considered to have evolved from protists because protists are single-celled eukaryotic organisms that show a wide range of cellular complexity and specialization, representing an early stage in the evolution of multicellular life. Bacteria are prokaryotic and significantly simpler, while fungi and plants evolved later and are distinct lineages.

Answer: A. Mg (OH)₂

Magnesium is in Group 2 of the periodic table, meaning it typically forms a +2 cation (Mg²⁺). Water molecules can react with magnesium to form magnesium hydroxide, where the hydroxide ion has a charge of -1 (OH⁻). To balance the charges and form a neutral compound, one Mg²⁺ ion needs two OH⁻ ions, resulting in Mg(OH)₂. Option B is incorrect because it implies a different charge on magnesium or hydroxide, and options C and D do not represent chemically stable or common compounds for magnesium.

Answer: D. Aldehydes

Aldehydes are oxidized by Tollens' reagent to carboxylic acids, and in the process, the silver ions in the reagent are reduced to metallic silver, which forms the characteristic silver mirror. Ketones, on the other hand, are generally resistant to oxidation by Tollens' reagent under mild conditions, making aldehydes the correct choice.

Answer: C. Non-metal of VII-A group

The electronic configuration [Ne] 5s²5p⁵ indicates that the element has 7 valence electrons (2 in 5s and 5 in 5p). Elements with 7 valence electrons are typically non

Answer: B. Continue to move in a straight line at constant velocity

According to Newton's first law of motion, an object in motion will stay in motion with the same speed and in the same direction unless acted upon by an unbalanced force. Therefore, if a moving object has no force acting on it, it will continue to move at a constant velocity in a straight line. Option A is incorrect because deceleration requires a force acting against the direction of motion. Option C is incorrect because an immediate stop would imply a force causing deceleration. Option D is incorrect because an increase in velocity (acceleration) requires a net force in the direction of motion.

Answer: A. instantaneous current, instantaneous voltage

The fundamental definition of instantaneous power ($P$) in an electrical circuit is the product of the instantaneous voltage ($V$) across a component and the instantaneous current ($I$) flowing through it. Therefore, $P = V \times I$. Option A correctly states these two quantities. Option B is incorrect because power is not a factor in the definition of instantaneous power.

Answer: D. Would

"Would you like..." is the most polite and common way to offer something to someone. While "Can you like..." is grammatically incorrect, "May I have..." or "Can I have..." are common ways to ask for something, making "May" and "Can" tempting incorrect options. "Shall" is typically used for suggestions or offers to the speaker ("Shall we go?").