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
51
In the symbol $^{23}_{11}Na$, what does the number 23 represent?
Answer:
The mass number
In standard nuclear notation, the superscript represents the mass number ($A$), which is the sum of protons and neutrons. The subscript represents the atomic number ($Z$).
52
How does 'Active Immunity' develop in a person?
Answer:
By the body producing its own antibodies in response to an infection or vaccine
Active immunity occurs when the body's own immune system produces antibodies and memory cells after being exposed to a pathogen or a vaccine. This type of immunity is long-lasting because the body 'remembers' how to fight the specific pathogen.
53
What is the charge of an alpha particle?
Answer:
+2
An alpha particle is identical to a helium nucleus, consisting of 2 protons and 2 neutrons. Since protons are positive and neutrons are neutral, the overall charge is +2.
54
Which of the following is a bacterial disease that causes a thick, gray coating in the throat, making it hard to breathe?
Answer:
Diphtheria
Diphtheria is a serious bacterial infection. The hallmark sign is a sheet of thick, gray material covering the back of the throat, which can block the airway. It is prevented by the DTaP vaccine, which also covers Tetanus and Pertussis (Whooping Cough).
55
What is the purpose of 'Disinfectants' in controlling the spread of disease?
Answer:
To kill pathogens on inanimate objects and surfaces
Disinfectants are chemical agents used on non-living surfaces (like floors, countertops, and medical equipment) to destroy microorganisms. They are generally too toxic to be used directly on human skin or tissue.
56
Which of the following describes an isotope?
Answer:
Atoms with the same atomic number but different mass numbers
Isotopes are variants of a particular chemical element which differ in neutron number, and consequently in nucleon number. All isotopes of a given element have the same number of protons but different numbers of neutrons.
57
Which of the following terms refers to any microorganism that has the capability to cause a disease in its host?
Answer:
Pathogen
A pathogen is a biological agent that causes disease or illness to its host. While many microorganisms are harmless or even beneficial to humans, pathogens have evolved specific mechanisms to invade the body, evade the immune system, and disrupt normal physiological functions.
58
Which of the following diseases is spread by the 'Aedes aegypti' mosquito?
Answer:
Dengue Fever
While the Anopheles mosquito transmits Malaria, the Aedes aegypti mosquito is the primary vector for viruses that cause Dengue Fever, Zika, and Yellow Fever. These mosquitoes typically bite during the day.
59
Which subatomic particle was discovered using the cathode ray tube?
Answer:
Electron
J.J. Thomson used cathode ray tubes to show that rays emitted from the cathode were made of negatively charged particles, which he called 'corpuscles,' later known as electrons.
60
What is the main function of 'Antiseptics'?
Answer:
To kill or inhibit the growth of microorganisms on living tissue
Antiseptics are antimicrobial substances that are applied to living tissue/skin to reduce the possibility of infection. Examples include rubbing alcohol or iodine used on a cut. Disinfectants are similar but are too harsh for skin and are used on objects.