What is the main function of White Blood Cells (WBCs)?
✅ Correct Answer:Fight Infection
Explanation: White Blood Cells (WBCs), or leukocytes, are the soldiers of the body's immune system. Their primary function is to detect and fight infections caused by bacteria, viruses, and fungi. They produce antibodies and destroy harmful foreign particles. Unlike red blood cells, WBCs have a nucleus and can move out of blood vessels to reach infected tissues.
142
Which instrument is used to measure the purity of milk?
✅ Correct Answer:Lactometer
Explanation: A Lactometer is used to check the purity of milk by measuring its specific gravity (density). It works on Archimedes' principle: a solid suspended in a fluid will be buoyed up by a force equal to the weight of the fluid displaced. If water is added to milk, the density decreases, and the lactometer sinks deeper, indicating adulteration.
143
The energy of the Sun is produced by which process?
✅ Correct Answer:Nuclear Fusion
Explanation: The Sun generates energy through Nuclear Fusion, a process where hydrogen nuclei collide and fuse to form helium. This reaction releases an enormous amount of energy in the form of light and heat. It occurs in the Sun's core under extreme pressure and temperature. This energy travels to Earth and sustains almost all life on our planet.
144
Which layer of the atmosphere is closest to the Earth?
✅ Correct Answer:Troposphere
Explanation: The Troposphere is the lowest layer of Earth's atmosphere, extending from the surface up to about 10-15 km. It contains approximately 75% of the atmosphere's mass and 99% of its water vapor. Almost all weather phenomena, such as rain, clouds, and snow, occur in this layer. As you go higher in the troposphere, the temperature decreases.
145
The deficiency of Iodine causes which disease?
✅ Correct Answer:Goiter
Explanation: A deficiency of Iodine leads to Goiter, which is an enlargement of the thyroid gland in the neck. The thyroid gland uses iodine to produce hormones that regulate metabolism. When there isn't enough iodine, the gland works harder and swells up. This is why iodized salt is commonly used worldwide to prevent this condition and ensure proper thyroid function.
146
Which blood group is known as the Universal Recipient?
✅ Correct Answer:Group AB+
Explanation: Blood Group AB+ is known as the universal recipient because individuals with this blood type can receive red blood cells from any ABO blood group. This is because they have both A and B antigens on their red blood cells and no antibodies against A or B in their plasma. This makes them unique in emergency transfusion situations where specific blood types are unavailable.
147
What is the S.I. unit of Electric Current?
✅ Correct Answer:Ampere
Explanation: The SI unit of electric current is the Ampere (symbol: A), often shortened to 'amp'. It measures the rate of flow of electric charge past a point in a circuit. One ampere is equal to one coulomb of charge passing a point in one second. It is named after André-Marie Ampère, a French mathematician and physicist who is considered the father of electrodynamics.
148
Which vitamin is found in abundance in Carrots?
✅ Correct Answer:Vitamin A
Explanation: Carrots are rich in Beta-carotene, which the human body converts into Vitamin A. Vitamin A is essential for good vision, especially in low light, and helps prevent night blindness. It also maintains healthy skin and boosts the immune system. A deficiency in Vitamin A can lead to serious eye problems and increased susceptibility to infections.
149
The chemical name of 'Dry Ice' is:
✅ Correct Answer:Solid Carbon Dioxide
Explanation: Dry Ice is the solid form of Carbon Dioxide (CO2). It is called 'dry' because it sublimates, meaning it changes directly from a solid to a gas without passing through a liquid phase. It is extremely cold (-78.5°C) and is used for refrigeration, preserving frozen foods during transport, and creating fog effects in theaters.
150
Which gas is used in the preparation of soda water?
✅ Correct Answer:Carbon Dioxide
Explanation: Carbon Dioxide (CO2) is dissolved in water under high pressure to create soda water or carbonated beverages. When the pressure is released by opening the bottle, the gas escapes as bubbles, giving the drink its fizzy taste. It acts as a preservative and adds a sharp, acidic flavor to the drink. Without CO2, soft drinks would taste flat and sugary.
151
Which part of the plant absorbs water and minerals from the soil?
✅ Correct Answer:Roots
Explanation: Roots are the part of the plant that anchors it to the ground and absorbs water and dissolved minerals from the soil. They have tiny root hairs that increase the surface area for maximum absorption. The absorbed water and nutrients are then transported up to the stem and leaves.
152
GPS stands for:
✅ Correct Answer:Global Positioning System
Explanation: GPS stands for Global Positioning System. It is a satellite-based radionavigation system owned by the US government. It provides geolocation and time information to a GPS receiver anywhere on or near the Earth. It is essential for navigation in cars, planes, and smartphones.
153
The nearest star to the Earth (other than the Sun) is:
✅ Correct Answer:Proxima Centauri
Explanation: Proxima Centauri is the nearest known star to the Earth after the Sun. It is a red dwarf star located about 4.24 light-years away in the constellation Centaurus. It is part of the Alpha Centauri star system. Despite being the closest, it is too faint to be seen with the naked eye.
154
Which vitamin helps in the absorption of Calcium?
✅ Correct Answer:Vitamin D
Explanation: Vitamin D is essential for the absorption of Calcium in the gut. Without sufficient Vitamin D, the body cannot absorb enough calcium from the diet, leading to the body taking calcium from its own stores in the skeleton. This weakens existing bone and prevents the formation of strong, new bone.
155
The pH value of pure water is:
✅ Correct Answer:7
Explanation: The pH of pure water is 7, which is considered neutral. The pH scale ranges from 0 to 14. Substances with a pH less than 7 are acidic, while those with a pH greater than 7 are basic (alkaline). Pure water is neither acidic nor basic, making it safe for consumption and life.
156
Which gas is used in fire extinguishers?
✅ Correct Answer:Carbon Dioxide
Explanation: Carbon Dioxide (CO2) is commonly used in fire extinguishers, especially for electrical fires and flammable liquid fires. CO2 works by displacing oxygen, which the fire needs to burn, and by cooling the fuel. Since CO2 is a gas, it does not leave a residue, making it ideal for delicate equipment.
157
Bronze is an alloy of Copper and:
✅ Correct Answer:Tin
Explanation: Bronze is an alloy consisting primarily of Copper, usually with Tin as the main additive. It is harder and more durable than copper alone. The Bronze Age was a significant period in human history when bronze tools and weapons replaced stone ones. It is also used in statues and medals.
158
Which planet has the most moons?
✅ Correct Answer:Saturn
Explanation: As of recent discoveries, Saturn holds the record for the planet with the most moons in our Solar System. It surpassed Jupiter with the confirmation of new moons, bringing its total to over 140. Titan is its largest and most famous moon. These moons vary greatly in size and composition.
159
Light Year is a unit of:
✅ Correct Answer:Distance
Explanation: A Light Year is a unit of astronomical distance. It represents the distance that light travels in a vacuum in one year (about 9.46 trillion kilometers). Because space is so vast, astronomers use light years to describe distances to stars and galaxies, as kilometers would result in unmanageably large numbers.
160
Dialysis is used for the treatment of which organ failure?
✅ Correct Answer:Kidney
Explanation: Dialysis is a medical treatment used when the Kidneys stop working properly (kidney failure). The kidneys are responsible for filtering waste and excess fluid from the blood. When they fail, dialysis takes over this function artificially, removing toxins and maintaining the balance of minerals in the blood.