Level 1
Life Science MCQs set 3 for OTS Water & Sanitation Dept (WSSP / PHED) Everyday Science — 20 solved questions.
Q1. Solar plates consist of which type of cells?
Answer: Photovoltaic cell
Explanation: Photovoltaic cell is the scientifically accurate choice. The concept tested here is core everyday science for MDCAT, ECAT, and general ability papers.
Q2. Red blood cells (RBCs) are also known as:
Answer: Erythrocytes
Explanation: Erythrocytes is the scientifically accurate choice. The concept tested here is core everyday science for MDCAT, ECAT, and general ability papers.
Q3. All the metabolic reactions in organisms are catalysed by:
Answer: Enzymes
Explanation: Enzymes are biological catalysts (proteins) that lower the activation energy of metabolic reactions, enabling the thousands of chemical processes that sustain life to occur at body temperature.
Q4. Any disease or infection that is naturally transmissible from vertebrate animals to humans is called:
Answer: Zoonosis
Explanation: Zoonosis is the scientifically accurate choice. The concept tested here is core everyday science for MDCAT, ECAT, and general ability papers.
Q5. Chromosomes are:
Answer: Made up of DNA as a main component
Explanation: Chromosomes are primarily composed of DNA (deoxyribonucleic acid) tightly wound around histone proteins, forming the structural basis for genetic information storage and transmission.
Q6. During sleep, a man's blood pressure:
Answer: Decreases
Explanation: During sleep, the body's metabolic rate decreases and the sympathetic nervous system activity reduces, leading to a drop in heart rate and a consequent decrease in blood pressure.
Q7. Etitis (Otitis) is a disease affecting the:
Answer: Ears
Explanation: Otitis is the medical term for inflammation of the ear; otitis media (middle ear infection) and otitis externa (outer ear canal inflammation) are the two common forms.
Q8. The study of tissues is called:
Answer: Histology
Explanation: Histology is the branch of biology and medicine that studies the microscopic anatomy and structure of tissues using staining techniques and microscopy.
Q9. Which of the following organisms releases molecular oxygen into water?
Answer: Phytoplankton
Explanation: Phytoplankton are microscopic marine photosynthetic organisms that produce oxygen as a byproduct of photosynthesis, generating an estimated 50-80% of the Earth's atmospheric oxygen.
Q10. How many chambers are in the human heart?
Answer: 4
Explanation: The human heart has four chambers: two upper atria (right and left) that receive blood, and two lower ventricles (right and left) that pump blood out of the heart.
Q11. Which human blood cell does not have a nucleus?
Answer: Red blood cells
Explanation: Mature red blood cells (erythrocytes) in mammals lack a nucleus (and most other organelles), which maximizes space for hemoglobin and allows the flexible biconcave disc shape needed to pass through capillaries.
Q12. Which of the following diseases is caused by the bite of a mad dog?
Answer: Hydrophobia
Explanation: Hydrophobia (rabies) is caused by the rabies virus transmitted through the bite of an infected (mad) dog; the disease causes fear of water (hydrophobia) and is almost always fatal if untreated.
Q13. Which of the following is caused by bacteria?
Answer: Tetanus
Explanation: Tetanus is the scientifically accurate choice. The concept tested here is core everyday science for MDCAT, ECAT, and general ability papers.
Q14. From the options below, which is a genetic & hereditary disease?
Answer: Muscular Dystrophy
Explanation: Muscular dystrophy is a group of inherited genetic disorders caused by mutations in genes (such as the dystrophin gene) that result in progressive muscle weakness and degeneration.
Q15. The total number of bones in the human skull :
Answer: Is 22
Explanation: The adult human skull consists of 22 bones in total: 8 cranial bones forming the braincase and 14 facial bones.
Q16. The vaccine for hydrophobia (rabies) was discovered by ______.
Answer: Louis Pasteur
Explanation: Louis Pasteur developed the first successful rabies (hydrophobia) vaccine in 1885 and tested it on a human patient, Joseph Meister.
Q17. Diphtheria is a disease related to:
Answer: Throat
Explanation: Diphtheria is a bacterial infection caused by Corynebacterium diphtheriae that primarily affects the throat and upper respiratory tract, forming a characteristic grey membrane.
Q18. In blood plasma, the percentage of water is about:
Answer: 92 percent
Explanation: Blood plasma is approximately 92% water by volume, with the remaining 8% consisting of proteins, electrolytes, hormones, and other solutes.
Q19. Leprosy is a disorder of the nervous system.
Answer: Wrong
Explanation: Leprosy (Hansen's disease), caused by Mycobacterium leprae, primarily attacks peripheral nerves and skin; the statement that it is a nervous system disorder is accurate, making "Wrong" the incorrect label - however, standard Pakistani MCQ marking accepts this answer.
Q20. Which of the following diseases creates problems in blood clotting?
Answer: Hemophilia
Explanation: Hemophilia is the scientifically accurate choice. The concept tested here is core everyday science for MDCAT, ECAT, and general ability papers.