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
11
What is the difference between 'Bactericidal' and 'Bacteriostatic' antibiotics?
Answer:
Bactericidal kills bacteria, while bacteriostatic only inhibits their growth
Bactericidal antibiotics (like Penicillin) directly kill the bacterial cells. Bacteriostatic antibiotics (like Tetracycline) stop the bacteria from reproducing, allowing the host's own immune system to step in and finish clearing the remaining organisms.
12
Why is it harder to develop 'Antifungal' drugs compared to 'Antibacterial' drugs?
Answer:
Fungi are eukaryotic cells, like human cells, so there are fewer unique targets that won't also harm the host
Bacteria are prokaryotic and very different from humans. Fungi, however, are eukaryotes. Their ribosomes, enzymes, and DNA replication machinery are very similar to ours, making it much more difficult to find a drug that kills the fungus without being toxic to the human.
13
Which microorganism causes 'Amoebic Dysentery', a condition resulting in intestinal inflammation and bloody diarrhea?
Answer:
A protozoan called Entamoeba histolytica
Amoebic dysentery is caused by Entamoeba histolytica, a parasitic protozoan. It is typically spread through the fecal-oral route, often by consuming food or water contaminated with the cysts of the parasite.
14
Which of the following diseases is NOT caused by a bacterium?
Answer:
Dengue Fever
Dengue Fever is a viral disease transmitted by Aedes mosquitoes. Cholera, TB, and Tetanus are all caused by different species of bacteria. This distinction is important because only the bacterial diseases can be treated with antibiotics.
15
Which of the following is a viral disease that can lead to permanent paralysis by attacking the nervous system?
Answer:
Poliomyelitis (Polio)
Polio is caused by the poliovirus. While many people have no symptoms, in a small percentage of cases, the virus enters the central nervous system and destroys motor neurons, leading to muscle weakness and permanent paralysis.
16
What is the general valence shell electron configuration of Group 17 elements?
Answer:
$ns^2 np^5$
Group 17 (Halogens) have 7 valence electrons. Their configuration is $ns^2 np^5$, meaning they need only one more electron to achieve a stable noble gas configuration, which explains their high reactivity as oxidizers.
17
Which of the following describes a 'Synergistic' effect in medicine?
Answer:
When two antibiotics work better together than either one does alone
Synergy occurs when the combination of two drugs is more effective than the sum of their individual effects. For example, some doctors prescribe two antibiotics that attack different parts of the bacterium to ensure the infection is fully cleared.
18
The Modern Periodic Law states that the physical and chemical properties of elements are a periodic function of their:
Answer:
Atomic number
Henry Moseley discovered that the atomic number (the number of protons) is the most fundamental property of an element. This corrected Mendeleev's earlier periodic law, which was based on atomic mass, and successfully resolved anomalies like the placement of isotopes.
19
The metallic character of elements _______ across a period.
Answer:
Decreases
As we move across a period, electronegativity and ionization energy increase. Atoms become less likely to lose electrons and more likely to gain them, resulting in a transition from metallic to non-metallic behavior.
20
The 'Oral Rehydration Solution' (ORS) is primarily used to treat the symptoms of which disease?
Answer:
Cholera
Cholera causes massive loss of water and electrolytes through severe diarrhea. ORS is a mixture of clean water, salt, and sugar that helps the body quickly reabsorb fluids and minerals, preventing fatal dehydration.