General Science/Everyday Science MCQs
Topic Notes: General Science/Everyday Science
MCQs and preparation resources for competitive exams, covering important concepts, past papers, and detailed explanations.
Plato
- Biography: Ancient Greek philosopher (427–347 BCE), student of Socrates and teacher of Aristotle, founder of the Academy in Athens.
- Important Ideas:
- Theory of Forms
- Philosopher-King
- Ideal State
21
Which of the following is a fungal infection of the scalp that causes patches of hair loss?
Answer:
Ringworm of the scalp (Tinea capitis)
Tinea capitis is a fungal infection (ringworm) that specifically affects the scalp and hair shafts. It often causes itchy, scaly patches and can lead to brittle hair that breaks off, resulting in temporary bald spots.
22
Hepatitis A is a disease that affects which organ in the human body?
Answer:
Liver
Hepatitis refers to the inflammation of the liver. Hepatitis A is a viral infection usually spread through contaminated food or water. It causes symptoms like jaundice (yellowing of the skin and eyes), fatigue, and abdominal pain.
23
Which of the following is a potential risk associated with the overuse of 'Broad-spectrum' antibiotics?
Answer:
The development of a superinfection (like C. diff) due to the loss of normal gut flora
Broad-spectrum antibiotics kill a wide variety of bacteria, including the 'good' ones in our intestines that keep harmful ones in check. When the good bacteria are gone, opportunistic pathogens like Clostridioides difficile can overgrow, causing severe illness.
24
Some bacteria produce an enzyme called 'Beta-lactamase'. What is the function of this enzyme?
Answer:
It breaks down the structure of penicillin-type antibiotics, making them useless
Beta-lactamase is a resistance mechanism. The enzyme cuts the 'beta-lactam ring' found in the chemical structure of many antibiotics (like Penicillin and Amoxicillin), deactivating the drug before it can harm the bacterium.
25
Antibiotic resistance occurs when bacteria develop the ability to defeat the drugs designed to kill them. What is a major cause of this phenomenon?
Answer:
Overuse and misuse of antibiotics in humans and livestock
When antibiotics are used too often or for viral infections (where they don't work), it puts selective pressure on bacterial populations. Only the most resistant bacteria survive and multiply, eventually creating 'superbugs' like MRSA that are very difficult to treat.
26
Which type of bonding involves the complete transfer of electrons from one atom to another?
Answer:
Ionic
Ionic bonding occurs when an atom (usually a metal) loses electrons to another atom (usually a non-metal), resulting in the formation of positive and negative ions that attract each other electrostatically.
27
The most metallic element in the Periodic Table is:
Answer:
Cesium
Cesium (and Francium, though it is radioactive and rare) is the most metallic because it has the largest atomic radius and lowest ionization energy in its stable form, allowing it to lose its valence electron very easily.
28
The ionic radius of a cation is always _______ than its parent atom.
Answer:
Smaller
When an atom loses electrons to form a cation, the remaining electrons experience a stronger pull from the nucleus. Often, an entire outer shell is lost, significantly reducing the radius.
29
Which of the following is considered a 'non-communicable' condition that can result from a microbial infection?
Answer:
Rheumatic heart disease (following a strep throat infection)
While most infections are communicable (spread person-to-person), some lead to non-communicable complications. For example, an untreated bacterial 'strep throat' can trigger an autoimmune response leading to Rheumatic heart disease, which itself cannot be passed to others.
30
In 1943, Selman Waksman discovered Streptomycin. Why was this antibiotic particularly significant?
Answer:
It was the first effective treatment for Tuberculosis
Penicillin was not very effective against the bacteria that cause Tuberculosis (TB). Streptomycin, isolated from soil bacteria, was the first antibiotic that could successfully treat TB, saving countless lives from the 'White Plague'.