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
161
Which of the following is a metalloid?
Answer:
Silicon
Metalloids (or semi-metals) have properties intermediate between metals and non-metals. Silicon is a classic example, used widely in semiconductors due to its specific electrical properties.
162
The MMR vaccine provides protection against which three diseases?
Answer:
Measles, Mumps, Rubella
The MMR vaccine is a combination vaccine that protects against Measles (a respiratory virus with a rash), Mumps (swelling of salivary glands), and Rubella (German measles). It is a standard part of childhood immunization schedules.
163
Which subatomic particle is the lightest?
Answer:
Electron
The mass of an electron is approximately $9.11 imes 10^{-31}$ kg, which is about 1840 times smaller than the mass of a proton or neutron.
164
Who developed the first successful vaccine for Rabies and also the process of heat-treating milk to kill pathogens?
Answer:
Louis Pasteur
Louis Pasteur was a French scientist who made massive contributions to microbiology. He developed vaccines for chicken cholera, anthrax, and rabies, and invented 'pasteurization' to prevent spoilage in food and beverages.
165
How do 'Antiviral' drugs differ from 'Antibiotics'?
Answer:
Antivirals inhibit the development of viruses, while antibiotics kill bacteria
Antibiotics kill bacteria or stop them from growing. Antivirals do not 'kill' viruses (as viruses aren't technically alive); instead, they interfere with the virus's ability to enter a host cell, replicate its genetic material, or exit the cell.
166
What role do 'Plasma Cells' play after a person is vaccinated?
Answer:
They are specialized B cells that secrete large amounts of antibodies into the blood
When the immune system is activated by a vaccine, B cells multiply and differentiate. Plasma cells are the 'antibody factories' that produce the actual Y-shaped proteins (antibodies) that stick to the pathogens and mark them for destruction.
167
How does the 'Innate' immune system differ from the 'Adaptive' immune system targeted by vaccines?
Answer:
Innate is non-specific and always present, while Adaptive is highly specific and has memory
Innate immunity includes physical barriers (skin) and general cells (phagocytes) that attack anything foreign. Adaptive immunity (which vaccines train) is the specialized 'elite force' that targets a specific pathogen and creates a memory for it.
168
Which component of the immune system is primarily targeted by vaccines to ensure future protection?
Answer:
Specific antibodies and memory cells
While the innate immune system (like skin) is the first line of defense, vaccines target the adaptive immune system. The goal is to produce specific antibodies that can bind to the pathogen and memory cells that 'remember' it for future encounters.
169
How is the bacterium 'Vibrio cholerae', which causes Cholera, typically transmitted to humans?
Answer:
Through contaminated food and water
Cholera is a classic waterborne disease. The bacteria are shed in the feces of infected people and can contaminate water supplies or food handled with poor hygiene. Ingesting this contaminated material leads to severe intestinal infection and rapid dehydration.
170
Which period contains the most elements?
Answer:
Period 6
Period 6 is the longest period, containing 32 elements. This includes the s-block, p-block, d-block, and the 14 f-block elements (Lanthanides).