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
1
A bacteriophage is a type of:
Answer:
Virus that infects bacteria
Bacteriophages, or 'phages,' are viruses that specifically target and infect bacterial cells. They attach to the bacterial surface, inject their genetic material, and hijack the bacterial machinery to produce new viral particles, often causing the host cell to burst (lysis).
2
What is the primary component of the cell wall in most fungal species?
Answer:
Chitin
The cell walls of fungi are primarily composed of chitin, a tough and flexible polysaccharide. This distinguishes them from plants, which have cellulose-based cell walls, and bacteria, which have peptidoglycan-based cell walls. Chitin provides structural support and protection to the fungal cells.
3
Which microorganism acts as a decomposer in the ecosystem by breaking down complex organic matter into simpler minerals?
Answer:
Bacteria and Fungi
Both bacteria and fungi play critical roles as decomposers. They break down organic waste and dead organisms, releasing essential nutrients like nitrogen and phosphorus back into the soil or water. Without these microorganisms, ecosystems would be overwhelmed with waste and nutrient cycles would stop.
4
Which of the following describes the shape of 'Cocci' bacteria?
Answer:
Spherical
Bacteria are often classified by their physical shapes. Cocci are spherical or round bacteria; Bacilli are rod-shaped; Spirilla are spiral-shaped; and Vibrios are comma-shaped. Examples of cocci include Streptococcus, which causes strep throat.
5
Fungi store their excess food energy in the form of:
Answer:
Glycogen
Like animals, fungi store their excess carbohydrates as glycogen. This is different from plants, which store energy as starch. This shared characteristic is one of several reasons why fungi are considered more closely related to animals than to plants.
6
The symbiotic association between a fungus and an alga is known as:
Answer:
Lichen
A lichen is a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungal species in a mutualistic relationship. The fungus provides structure and protection, while the algae produce food through photosynthesis, allowing the lichen to survive in harsh environments.
7
In a laboratory, which instrument is used to visualize objects as small as viruses?
Answer:
Electron microscope
Standard light (compound) microscopes have a limit to their resolution and cannot see viruses. Electron microscopes use a beam of electrons instead of light, allowing for much higher magnification and resolution, which is necessary to see the fine structure of viral particles.
8
Which of these is a common viral disease that affects the respiratory system and causes seasonal outbreaks?
Answer:
Influenza (Flu)
Influenza, commonly known as the flu, is a highly contagious respiratory illness caused by influenza viruses. It spreads through the air when people cough or sneeze. Cholera and Tetanus are bacterial diseases, while Dysentery can be caused by bacteria or protozoa.
9
What is the term for a microorganism that causes disease in its host?
Answer:
Pathogen
A pathogen is any organism that causes disease. This includes certain types of bacteria, viruses, fungi, and protozoa. While many microorganisms are harmless or even beneficial (like those in our gut), pathogens have specialized mechanisms to invade hosts and cause harm.
10
Which type of vaccine contains weakened or 'killed' versions of a virus or bacteria to stimulate the immune system?
Answer:
Immunization
Vaccines work by introducing a harmless version of a pathogen (or pieces of it) into the body. This 'trains' the immune system to recognize and fight the actual pathogen if it ever invades in the future, providing long-term protection known as immunization.