About Science MCQs
Science is a core subject in almost every competitive examination, including CSS, PMS, PPSC, FPSC, and NTS. It encompasses the study of the physical world and natural phenomena. Whether you are preparing for a general science paper or a specialized entry test, mastering Science MCQs requires a clear understanding of fundamental concepts and the ability to apply them logically.
Topics Covered in This Category
- Biology: Human anatomy, cell biology, genetics, and ecology.
- Chemistry: Chemical reactions, periodic table, organic and inorganic chemistry.
- Physics: Mechanics, electricity, magnetism, optics, and modern physics.
- Everyday Science: Practical applications of science in daily life, famous inventions, and scientific laws.
How to Prepare for Science Exams
Science is not just about memorizing facts; it is about understanding the "why" and "how" behind natural phenomena. Focus on conceptual clarity rather than rote learning. When practicing MCQs, pay special attention to units of measurement, chemical formulas, and scientific terminologies. Reviewing the explanations for wrong answers is the fastest way to improve your score.
Practice 49 Biomolecules MCQs
Question 1: Which molecule is known as the energy currency of the cell?
- A DNA
- B RNA
- C Cellulose
- D ATP
Explanation: ATP stores and transfers usable energy. Useful for: MDCAT 2027, NUMS 2027.
Question 2: Which organelle is the site of protein synthesis?
- A Golgi apparatus
- B Ribosome
- C Lysosome
- D Vacuole
Explanation: Ribosomes translate mRNA into proteins. Useful for: MDCAT 2027, NUMS 2027.
Question 3: Which organelle is called the powerhouse of the cell?
- A Mitochondria
- B Nucleus
- C Ribosome
- D Golgi apparatus
Explanation: Mitochondria produce most of the cell's ATP. Useful for: MDCAT 2027, NUMS 2027.
Question 4: Which enzyme unwinds the DNA double helix during replication?
- A Ligase
- B DNA polymerase
- C Helicase
- D Primase
Explanation: Helicase breaks hydrogen bonds between base pairs to open the replication fork. Useful for: MDCAT 2027, NUMS 2027.
Question 5: Who is known as the father of genetics?
- A James Watson
- B Jean-Baptiste Lamarck
- C Charles Darwin
- D Gregor Mendel
Explanation: Mendel's pea-plant experiments founded genetics. Useful for: MDCAT 2027, NUMS 2027.
Question 6: How many pairs of chromosomes does a human cell have?
- A 46 pairs
- B 22 pairs
- C 23 pairs
- D 24 pairs
Explanation: Humans have 46 chromosomes, i.e. 23 pairs. Useful for: MDCAT 2027, NUMS 2027.
Question 7: Which blood cell fragments are mainly responsible for blood clotting?
- A Erythrocytes
- B Platelets
- C Lymphocytes
- D Neutrophils
Explanation: Platelets (thrombocytes) form plugs and trigger the clotting cascade. Useful for: MDCAT 2027, NUMS 2027.
Question 8: Which heart chamber pumps oxygenated blood to the body?
- A Right ventricle
- B Left ventricle
- C Right atrium
- D Left atrium
Explanation: The left ventricle pumps blood into the aorta. Useful for: MDCAT 2027, NUMS 2027.
Question 9: Which enzyme in saliva begins the digestion of starch?
- A Salivary amylase
- B Lipase
- C Trypsin
- D Pepsin
Explanation: Amylase breaks starch into sugars in the mouth. Useful for: MDCAT 2027, NUMS 2027.
Question 10: Which of the following is a bacterial disease?
- A Malaria
- B Tuberculosis
- C Influenza
- D Polio
Explanation: Tuberculosis is caused by Mycobacterium tuberculosis. Useful for: MDCAT 2027, NUMS 2027.
Question 11: Which pigment gives plants their green colour?
- A Anthocyanin
- B Carotene
- C Chlorophyll
- D Xanthophyll
Explanation: Chlorophyll absorbs light for photosynthesis. Useful for: MDCAT 2027, NUMS 2027.
Question 12: Which gas is released when zinc reacts with dilute hydrochloric acid?
- A Chlorine
- B Carbon dioxide
- C Hydrogen
- D Oxygen
Explanation: Zn + 2HCl → ZnCl2 + H2. Useful for: MDCAT 2027, NUMS 2027, ECAT.
Question 13: The pH of an acidic solution is:
- A Equal to 7
- B Greater than 7
- C Less than 7
- D Exactly 14
Explanation: Acids have pH below 7. Useful for: MDCAT 2027, NUMS 2027, ECAT.
Question 14: What is the atomic number of carbon?
- A 4
- B 6
- C 8
- D 12
Explanation: Carbon has 6 protons, so its atomic number is 6. Useful for: MDCAT 2027, NUMS 2027, ECAT.
Question 15: What is the chemical symbol of sodium?
- A Na
- B So
- C S
- D Sd
Explanation: Na comes from the Latin 'natrium'. Useful for: MDCAT 2027, NUMS 2027, ECAT.
Question 16: Which is the most electronegative element?
- A Fluorine
- B Oxygen
- C Chlorine
- D Nitrogen
Explanation: Fluorine has the highest electronegativity (3.98). Useful for: MDCAT 2027, NUMS 2027, ECAT.
Question 17: A bond formed by sharing of electron pairs is called:
- A Covalent bond
- B Metallic bond
- C Hydrogen bond
- D Ionic bond
Explanation: Covalent bonds involve electron sharing. Useful for: MDCAT 2027, NUMS 2027, ECAT.
Question 18: What is the hybridization of carbon in methane (CH4)?
- A sp
- B sp2
- C sp3
- D sp3d
Explanation: Carbon in methane forms four sigma bonds, giving sp3 hybridization and tetrahedral geometry (109.5°). Useful for: MDCAT 2027, NUMS 2027, ECAT.
Question 19: Avogadro's number is approximately:
- A 6.022 × 10^21
- B 1.6 × 10^-19
- C 6.022 × 10^23
- D 3.0 × 10^8
Explanation: One mole contains 6.022 × 10^23 particles. Useful for: MDCAT 2027, NUMS 2027, ECAT.
Question 20: The functional group of alcohols is:
- A -NH2
- B -OH
- C -COOH
- D -CHO
Explanation: Alcohols contain the hydroxyl (-OH) group. Useful for: MDCAT 2027, NUMS 2027, ECAT.
Question 21: The general formula of alkanes is:
- A CnH2n+2
- B CnH2n
- C CnHn
- D CnH2n-2
Explanation: Alkanes are saturated hydrocarbons with formula CnH2n+2. Useful for: MDCAT 2027, NUMS 2027, ECAT.
Question 22: Which of the following is a noble gas?
- A Nitrogen
- B Chlorine
- C Argon
- D Oxygen
Explanation: Argon belongs to Group 18 (noble gases) and is chemically inert. Useful for: MDCAT 2027, NUMS 2027, ECAT.
Question 23: What is the pH of pure water at 25°C?
- A 5
- B 7
- C 14
Explanation: Pure water is neutral, with a pH of 7 at 25°C. Useful for: PPSC, FPSC, NTS, CSS MPT, KPPSC, SPSC, BPSC, Police, PST/EST/SST.
Question 24: Which gas is the most abundant in Earth's atmosphere?
- A Nitrogen
- B Carbon dioxide
- C Argon
- D Oxygen
Explanation: Nitrogen makes up about 78% of the atmosphere. Useful for: PPSC, FPSC, NTS, CSS MPT, KPPSC, SPSC, BPSC, Police, PST/EST/SST.
Question 25: The ozone layer protects living things mainly from which radiation?
- A Microwaves
- B Radio waves
- C Infrared
- D Ultraviolet
Explanation: Ozone absorbs most of the Sun's harmful ultraviolet rays. Useful for: PPSC, FPSC, NTS, CSS MPT, KPPSC, SPSC, BPSC, Police, PST/EST/SST.
Question 26: Which blood group is known as the universal donor?
- A AB positive
- B O negative
- C A negative
- D B positive
Explanation: O negative red blood cells have no A, B or Rh antigens, so they can be given to almost any patient. Useful for: PPSC, FPSC, NTS, CSS MPT, KPPSC, SPSC, BPSC, Police, PST/EST/SST.
Question 27: Which organ of the human body produces insulin?
- A Liver
- B Kidney
- C Pancreas
- D Stomach
Explanation: Beta cells in the islets of Langerhans of the pancreas secrete insulin. Useful for: PPSC, FPSC, NTS, CSS MPT, KPPSC, SPSC, BPSC, Police, PST/EST/SST.
Question 28: Which part of the human eye controls the amount of light entering it?
- A Iris
- B Retina
- C Lens
- D Cornea
Explanation: The iris adjusts the size of the pupil. Useful for: PPSC, FPSC, NTS, CSS MPT, KPPSC, SPSC, BPSC, Police, PST/EST/SST.
Question 29: Which is the largest organ of the human body?
- A Skin
- B Heart
- C Lungs
- D Liver
Explanation: The skin is the body's largest organ. Useful for: PPSC, FPSC, NTS, CSS MPT, KPPSC, SPSC, BPSC, Police, PST/EST/SST.
Question 30: Deficiency of which vitamin causes scurvy?
- A Vitamin A
- B Vitamin B12
- C Vitamin C
- D Vitamin D
Explanation: Scurvy is caused by a lack of Vitamin C (ascorbic acid), found in citrus fruits. Useful for: PPSC, FPSC, NTS, CSS MPT, KPPSC, SPSC, BPSC, Police, PST/EST/SST.
Question 31: Which vitamin is produced in the skin on exposure to sunlight?
- A Vitamin C
- B Vitamin A
- C Vitamin D
- D Vitamin K
Explanation: Sunlight (UV-B) triggers vitamin D synthesis in the skin. Useful for: PPSC, FPSC, NTS, CSS MPT, KPPSC, SPSC, BPSC, Police, PST/EST/SST.
Question 32: Dengue fever is transmitted by which mosquito?
- A Tsetse fly
- B Aedes
- C Anopheles
- D Culex
Explanation: Dengue is spread by the Aedes mosquito; malaria by Anopheles. Useful for: PPSC, FPSC, NTS, CSS MPT, KPPSC, SPSC, BPSC, Police, PST/EST/SST.
Question 33: Deficiency of which mineral commonly causes anaemia?
- A Calcium
- B Sodium
- C Iron
- D Iodine
Explanation: Iron is needed to make haemoglobin. Useful for: PPSC, FPSC, NTS, CSS MPT, KPPSC, SPSC, BPSC, Police, PST/EST/SST.
Question 34: Which is the hardest natural substance known?
- A Diamond
- B Graphite
- C Quartz
- D Iron
Explanation: Diamond, a crystalline form of carbon, is the hardest naturally occurring substance. Useful for: PPSC, FPSC, NTS, CSS MPT, KPPSC, SPSC, BPSC, Police, PST/EST/SST.
Question 35: Which gas do green plants absorb from the air for photosynthesis?
- A Oxygen
- B Carbon dioxide
- C Nitrogen
- D Hydrogen
Explanation: Plants take in carbon dioxide and, using water and sunlight, produce glucose and release oxygen. Useful for: PPSC, FPSC, NTS, CSS MPT, KPPSC, SPSC, BPSC, Police, PST/EST/SST.
Question 36: Which planet is known as the Red Planet?
- A Venus
- B Mars
- C Jupiter
- D Mercury
Explanation: Mars appears red because of iron oxide (rust) on its surface. Useful for: PPSC, FPSC, NTS, CSS MPT, KPPSC, SPSC, BPSC, Police, PST/EST/SST.
Question 37: What is the SI unit of force?
- A Joule
- B Pascal
- C Newton
- D Watt
Explanation: Force is measured in newtons (N); 1 N = 1 kg·m/s². Useful for: PPSC, FPSC, NTS, CSS MPT, KPPSC, SPSC, BPSC, Police, PST/EST/SST.
Question 38: Which instrument is used to measure atmospheric pressure?
- A Thermometer
- B Anemometer
- C Barometer
- D Hygrometer
Explanation: A barometer measures air pressure. Useful for: PPSC, FPSC, NTS, CSS MPT, KPPSC, SPSC, BPSC, Police, PST/EST/SST.
Question 39: What is the SI unit of electrical resistance?
- A Ohm
- B Volt
- C Ampere
- D Farad
Explanation: Resistance is measured in ohms (Ω); from Ohm's law, R = V/I. Useful for: ECAT, MDCAT 2027, NUMS 2027.
Question 40: The SI unit of electric current is:
- A Volt
- B Ohm
- C Ampere
- D Coulomb
Explanation: Current is measured in amperes (A). Useful for: ECAT, MDCAT 2027, NUMS 2027.
Question 41: Which type of mirror is used as a rear-view mirror in vehicles?
- A Concave mirror
- B Plane mirror
- C Convex mirror
- D Cylindrical mirror
Explanation: A convex mirror gives a wider field of view. Useful for: ECAT, MDCAT 2027, NUMS 2027.
Question 42: The speed of light in vacuum is approximately:
- A 3 × 10^8 m/s
- B 3 × 10^6 m/s
- C 3 × 10^5 m/s
- D 3 × 10^10 m/s
Explanation: Light travels at about 3 × 10^8 m/s (300,000 km/s) in vacuum. Useful for: ECAT, MDCAT 2027, NUMS 2027.
Question 43: The approximate value of acceleration due to gravity on Earth's surface is:
- A 1.6 m/s²
- B 9.8 m/s²
- C 19.6 m/s²
- D 98 m/s²
Explanation: Near Earth's surface, g ≈ 9.8 m/s² (about 9.81 m/s²). Useful for: ECAT, MDCAT 2027, NUMS 2027.
Question 44: What is the SI unit of power?
- A Joule
- B Newton
- C Watt
- D Pascal
Explanation: Power is measured in watts (1 W = 1 J/s). Useful for: ECAT, MDCAT 2027, NUMS 2027.
Question 45: 'To every action there is an equal and opposite reaction' is which law?
- A Newton's second law
- B Newton's first law
- C Law of gravitation
- D Newton's third law
Explanation: This is Newton's third law of motion. Useful for: ECAT, MDCAT 2027, NUMS 2027.
Question 46: A body stays at rest or in uniform motion unless acted upon by an external force. This is:
- A Newton's second law
- B Hooke's law
- C Newton's first law
- D Newton's third law
Explanation: The first law is also called the law of inertia. Useful for: ECAT, MDCAT 2027, NUMS 2027.
Question 47: What is the formula for kinetic energy?
- A mv²
- B ½mv
- C mgh
- D ½mv²
Explanation: Kinetic energy = ½ × mass × velocity². Useful for: ECAT, MDCAT 2027, NUMS 2027.
Question 48: What is the SI unit of frequency?
- A Henry
- B Decibel
- C Hertz
- D Tesla
Explanation: Frequency is measured in hertz (cycles per second). Useful for: ECAT, MDCAT 2027, NUMS 2027.
Question 49: Sound cannot travel through:
- A Air
- B Water
- C Vacuum
- D Steel
Explanation: Sound needs a material medium to propagate. Useful for: ECAT, MDCAT 2027, NUMS 2027.
Frequently Asked Questions
How many Biomolecules MCQs are available on TestMasterMCQs?
There are currently 49 Biomolecules 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 Biomolecules MCQs useful for PPSC, FPSC, NTS, CSS and MDCAT?
Yes — our Biomolecules 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 Biomolecules 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.