Top 500 General Science GK Questions

Correct Answer : C
Explanation :

convex lenses are used in the human eye to help focus light onto the retina, allowing us to see clearly. The natural lens in the human eye is flexible and can change its shape, allowing it to adjust the focal length and focus on objects at different distances. This process is called accommodation and is essential for clear vision.

Correct Answer : C
Explanation :

lactic acid is one of the end products of anaerobic respiration in humans and some other organisms. During anaerobic respiration, which occurs in the absence of oxygen, glucose is partially broken down to generate energy. In the absence of oxygen, cells can convert pyruvate, a product of glycolysis, into lactic acid. This process, called lactic acid fermentation, helps generate energy in the absence of oxygen but also leads to the accumulation of lactic acid, causing muscle fatigue and soreness.

Correct Answer : D
Explanation :
The term "histology" was first used by the French physician Marie François Xavier Bichat, but it was popularized and introduced into English by the Swiss anatomist Karl Wilhelm von Nägeli in the early 19th century.

Correct Answer : B
Explanation :

The junction between the axon of one neuron and the dendrite (or cell body) of the next neuron is called a synapse. At the synapse, electrical or chemical signals are transmitted from one neuron to another or to an effector cell, such as a muscle cell or gland cell. Synapses play a crucial role in the transmission of nerve impulses within the nervous system.

Correct Answer : C
Explanation :
Chalk powder, which primarily consists of calcium carbonate, is relatively insoluble in water. While it can react very slowly with water over time to form soluble calcium bicarbonate, the solubility of chalk powder in water is extremely low, making it effectively insoluble for most practical purposes.

Correct Answer : D
Explanation :

Mercury and Venus are the two planets in our solar system that do not have any natural satellites (moons).

Correct Answer : D
Explanation :
Cats (and many other animals) have a layer of cells behind their retinas called the tapetum lucidum. This layer enhances night vision by reflecting light that passes through the retina back into the eyes. When light enters the eye, some of it is absorbed by the retina's cells, allowing the brain to process visual information. However, the tapetum lucidum reflects the remaining light back through the retina, giving the photoreceptor cells a second chance to detect the light. This reflection of light enhances their night vision capabilities and is what causes a cat's eyes to appear to glow in the dark or in low light conditions.

Correct Answer : B
Explanation :

The image formed by a plane mirror (also known as a flat mirror) is called a "virtual image." A virtual image is an image that is not real but appears as if it were. It is formed behind the mirror, and it appears to be the same size as the object being reflected. This image is upright (erect) and reversed from left to right, but it is not a tangible object; it exists as a result of the way light rays reflect off the mirror's surface.

Correct Answer : D
Explanation :

Flat Mirror (or Plane Mirror): Reflects light without distorting the image. The image formed is erect (upright) and of the same size as the object, but reversed from left to right.

Convex Mirror: Also produces an erect image. The image formed is virtual (cannot be projected onto a screen), smaller than the actual object, and upright.

Both flat and convex mirrors can create upright (erect) images of real objects.

Correct Answer : B
Explanation :

A torch emits a divergent light beam, where light rays spread out as they move away from the source. This spreading allows the flashlight to illuminate a wider area, making it useful for various tasks. Divergent beams are common in flashlights, ensuring efficient coverage and visibility in the dark.