Practice 50 Biological Molecules MCQs
Question 1: The sugar present in DNA is:
- A Deoxyribose
- B Glucose
- C Fructose
- D Ribose
Explanation: DNA contains deoxyribose. Useful for: MDCAT 2027, NUMS 2027.
Question 2: Who coined the term 'cell'?
- A Matthias Schleiden
- B Theodor Schwann
- C Rudolf Virchow
- D Robert Hooke
Explanation: Hooke named cells while viewing cork in 1665. Useful for: MDCAT 2027, NUMS 2027.
Question 3: Which organelle has its own DNA besides the nucleus?
- A Lysosome
- B Mitochondria
- C Golgi apparatus
- D Peroxisome
Explanation: Mitochondria contain circular DNA. Useful for: MDCAT 2027, NUMS 2027.
Question 4: In which phase of the cell cycle does DNA replication occur?
- A G2 phase
- B M phase
- C S phase
- D G1 phase
Explanation: S stands for synthesis. Useful for: MDCAT 2027, NUMS 2027.
Question 5: The scientific name of modern humans is:
- A Pan troglodytes
- B Homo erectus
- C Homo sapiens
- D Homo habilis
Explanation: Humans belong to the species Homo sapiens. Useful for: MDCAT 2027, NUMS 2027.
Question 6: Which kingdom includes yeast and mushrooms?
- A Plantae
- B Monera
- C Protista
- D Fungi
Explanation: Yeasts and mushrooms are fungi. Useful for: MDCAT 2027, NUMS 2027.
Question 7: Which base pairs with guanine in DNA?
- A Thymine
- B Cytosine
- C Adenine
- D Uracil
Explanation: G pairs with C by three hydrogen bonds. Useful for: MDCAT 2027, NUMS 2027.
Question 8: Which enzyme synthesises RNA from a DNA template?
- A Helicase
- B Ligase
- C RNA polymerase
- D DNA polymerase
Explanation: RNA polymerase carries out transcription. Useful for: MDCAT 2027, NUMS 2027.
Question 9: The process of making mRNA from DNA is called:
- A Mutation
- B Replication
- C Transcription
- D Translation
Explanation: Transcription produces RNA from DNA. Useful for: MDCAT 2027, NUMS 2027.
Question 10: A recessive trait is expressed only when the genotype is:
- A Homozygous recessive
- B Hemizygous dominant
- C Heterozygous
- D Homozygous dominant
Explanation: Two recessive alleles are needed. Useful for: MDCAT 2027, NUMS 2027.
Question 11: Red-green colour blindness is inherited as:
- A Autosomal recessive
- B Autosomal dominant
- C Y-linked
- D X-linked recessive
Explanation: The gene lies on the X chromosome. Useful for: MDCAT 2027, NUMS 2027.
Question 12: Which blood vessels have valves to prevent backflow?
- A Capillaries
- B Aorta
- C Arteries
- D Veins
Explanation: Veins carry blood at low pressure and need valves. Useful for: MDCAT 2027, NUMS 2027.
Question 13: Which organ produces bile?
- A Pancreas
- B Liver
- C Gall bladder
- D Stomach
Explanation: The liver makes bile; the gall bladder stores it. Useful for: MDCAT 2027, NUMS 2027.
Question 14: Which enzyme digests lipids?
- A Maltase
- B Amylase
- C Pepsin
- D Lipase
Explanation: Lipase breaks fats into fatty acids and glycerol. Useful for: MDCAT 2027, NUMS 2027.
Question 15: The inner layer of the eye containing photoreceptors is the:
- A Cornea
- B Retina
- C Iris
- D Sclera
Explanation: Rods and cones are in the retina. Useful for: MDCAT 2027, NUMS 2027.
Question 16: The cochlea is part of the:
- A Middle ear
- B Outer ear
- C Eustachian tube
- D Inner ear
Explanation: The cochlea converts sound vibrations into nerve signals. Useful for: MDCAT 2027, NUMS 2027.
Question 17: The main nitrogenous waste of humans is:
- A Ammonia
- B Uric acid
- C Creatinine
- D Urea
Explanation: The liver converts ammonia to urea. Useful for: MDCAT 2027, NUMS 2027.
Question 18: Which cells produce antibodies?
- A Erythrocytes
- B Platelets
- C B lymphocytes (plasma cells)
- D Neutrophils
Explanation: Plasma cells derived from B cells secrete antibodies. Useful for: MDCAT 2027, NUMS 2027.
Question 19: Hepatitis B is caused by a:
- A Virus
- B Fungus
- C Protozoan
- D Bacterium
Explanation: It is caused by the hepatitis B virus. Useful for: MDCAT 2027, NUMS 2027.
Question 20: Auxins are plant hormones mainly responsible for:
- A Cell elongation
- B Seed dormancy
- C Fruit ripening
- D Leaf fall
Explanation: Auxins promote stem elongation. Useful for: MDCAT 2027, NUMS 2027.
Question 21: A solution with pH 12 is:
- A Weakly acidic
- B Strongly basic
- C Strongly acidic
- D Neutral
Explanation: pH above 7 is basic. Useful for: MDCAT 2027, NUMS 2027.
Question 22: The reaction between an acid and a base is called:
- A Esterification
- B Hydrolysis
- C Neutralisation
- D Oxidation
Explanation: An acid and a base react to give salt and water. Useful for: MDCAT 2027, NUMS 2027.
Question 23: The mass number of an atom is the sum of its:
- A Protons and electrons
- B Neutrons and electrons
- C Electrons only
- D Protons and neutrons
Explanation: Mass number = protons + neutrons. Useful for: MDCAT 2027, NUMS 2027.
Question 24: Which of the following is a polysaccharide?
- A Fructose
- B Glucose
- C Starch
- D Sucrose
Explanation: Starch is a polymer of glucose. Useful for: MDCAT 2027, NUMS 2027.
Question 25: Which metal is obtained by the electrolysis of molten NaCl?
- A Zinc
- B Iron
- C Sodium
- D Copper
Explanation: Sodium forms at the cathode. Useful for: MDCAT 2027, NUMS 2027.
Question 26: The catalyst used in the Haber process is:
- A Nickel
- B Platinum
- C Iron
- D Vanadium pentoxide
Explanation: Finely divided iron catalyses ammonia synthesis. Useful for: MDCAT 2027, NUMS 2027.
Question 27: The chemical formula of sulphuric acid is:
- A HSO₄
- B H₂SO₃
- C HNO₃
- D H₂SO₄
Explanation: Sulphuric acid contains two H, one S and four O. Useful for: MDCAT 2027, NUMS 2027.
Question 28: Which gas is produced when calcium carbonate reacts with dilute HCl?
- A Oxygen
- B Chlorine
- C Carbon dioxide
- D Hydrogen
Explanation: CaCO₃ + 2HCl → CaCl₂ + H₂O + CO₂. Useful for: MDCAT 2027, NUMS 2027.
Question 29: Which of the following is a physical change?
- A Melting of ice
- B Rusting of iron
- C Burning of wood
- D Souring of milk
Explanation: Melting changes state without forming a new substance. Useful for: MDCAT 2027, NUMS 2027.
Question 30: Which alkane is the main component of natural gas?
- A Butane
- B Ethane
- C Propane
- D Methane
Explanation: Natural gas is mostly methane. Useful for: MDCAT 2027, NUMS 2027.
Question 31: Butane and 2-methylpropane show which type of isomerism?
- A Functional group isomerism
- B Geometrical isomerism
- C Position isomerism
- D Chain isomerism
Explanation: They differ in the carbon-chain arrangement. Useful for: MDCAT 2027, NUMS 2027.
Question 32: Which element is the most abundant in the Earth's crust?
- A Oxygen
- B Silicon
- C Iron
- D Aluminium
Explanation: Oxygen makes up nearly half the crust by mass. Useful for: MDCAT 2027, NUMS 2027.
Question 33: Lungs : Breathing :: Heart : ?
- A Pumping blood
- B Filtering
- C Thinking
- D Digestion
Explanation: The heart's function is circulating blood. Useful for: MDCAT 2027, NUMS 2027.
Question 34: Choose the correct sentence (present perfect continuous).
- A She is studying since morning.
- B She was study since morning.
- C She has been studying since morning.
- D She studied since morning.
Explanation: 'Has been + -ing' with 'since' is correct. Useful for: MDCAT 2027, NUMS 2027.
Question 35: Find the next number: 7, 14, 21, 28, ?
- A 32
- B 42
- C 30
- D 35
Explanation: The series increases by 7. Useful for: MDCAT 2027, NUMS 2027.
Question 36: Choose the odd one out: Aspirin, Paracetamol, Ibuprofen, Insulin
- A Insulin
- B Paracetamol
- C Ibuprofen
- D Aspirin
Explanation: Insulin is a hormone; the others are painkillers. Useful for: MDCAT 2027, NUMS 2027.
Question 37: Choose the synonym of 'VIGILANT'.
- A Sleepy
- B Watchful
- C Tired
- D Careless
Explanation: Vigilant means alert and watchful. Useful for: MDCAT 2027, NUMS 2027.
Question 38: Choose the antonym of 'HOSTILE'.
- A Violent
- B Aggressive
- C Rude
- D Friendly
Explanation: Hostile means unfriendly. Useful for: MDCAT 2027, NUMS 2027.
Question 39: The charge on an electron is approximately:
- A −9.1 × 10⁻³¹ C
- B +1.6 × 10⁻¹⁹ C
- C −1.6 × 10⁻¹⁹ C
- D 1.6 × 10⁻¹⁹ J
Explanation: The electron carries the elementary negative charge. Useful for: MDCAT 2027, NUMS 2027.
Question 40: The mass of a proton is about ___ times that of an electron.
- A 18
- B 10,000
- C 1,836
- D 100
Explanation: The proton is roughly 1,836 times heavier. Useful for: MDCAT 2027, NUMS 2027.
Question 41: In a resistor, electrical energy is mainly converted into:
- A Chemical energy
- B Light only
- C Heat
- D Sound
Explanation: Joule heating occurs in resistors. Useful for: MDCAT 2027, NUMS 2027.
Question 42: The kilowatt-hour is a unit of:
- A Current
- B Power
- C Charge
- D Energy
Explanation: 1 kWh = 3.6 × 10⁶ J. Useful for: MDCAT 2027, NUMS 2027.
Question 43: Which device converts mechanical energy into electrical energy?
- A Motor
- B Generator
- C Battery
- D Transformer
Explanation: A generator works by electromagnetic induction. Useful for: MDCAT 2027, NUMS 2027.
Question 44: Which device converts electrical energy into mechanical energy?
- A Capacitor
- B Rectifier
- C Electric motor
- D Generator
Explanation: A motor uses the force on a current in a magnetic field. Useful for: MDCAT 2027, NUMS 2027.
Question 45: The SI unit of luminous intensity is the:
- A Kelvin
- B Lumen
- C Lux
- D Candela
Explanation: Candela is one of the seven SI base units. Useful for: MDCAT 2027, NUMS 2027.
Question 46: Which type of mirror do dentists use?
- A Convex mirror
- B Plane mirror
- C Concave mirror
- D Cylindrical mirror
Explanation: A concave mirror gives an enlarged image at close range. Useful for: MDCAT 2027, NUMS 2027.
Question 47: One standard atmosphere is approximately equal to:
- A 1,000 Pa
- B 1,013 Pa
- C 10,000 Pa
- D 101,325 Pa
Explanation: 1 atm = 101.325 kPa. Useful for: MDCAT 2027, NUMS 2027.
Question 48: Archimedes' principle is related to:
- A Viscosity
- B Buoyant force
- C Surface tension
- D Friction
Explanation: A body in a fluid feels an upward buoyant force. Useful for: MDCAT 2027, NUMS 2027.
Question 49: Heat transfer by direct contact is called:
- A Radiation
- B Conduction
- C Convection
- D Evaporation
Explanation: Conduction occurs through touching particles. Useful for: MDCAT 2027, NUMS 2027.
Question 50: The unit of specific heat capacity is:
- A J kg⁻¹ K⁻¹
- B J K⁻¹
- C kg K J⁻¹
- D J kg⁻¹
Explanation: c = Q/(mΔT). Useful for: MDCAT 2027, NUMS 2027.
Frequently Asked Questions
How many Biological Molecules MCQs are available on TestMasterMCQs?
There are currently 50 Biological Molecules MCQs on this page, each with four options, the correct answer and a short explanation to help you understand the concept — not just memorise the answer.
Are these Biological Molecules MCQs useful for PPSC, FPSC, NTS, CSS and MDCAT?
Yes — our Biological Molecules questions follow the syllabus of common Pakistani competitive exams including CSS, PMS, PPSC, FPSC, NTS, and university entry tests like MDCAT and ECAT.
How should I practice Biological Molecules MCQs for better retention?
Attempt 15–20 questions at a time, read the explanation after every question (even the ones you get right), and revisit wrong answers after 24 hours to reinforce memory.