Physical and Life Sciences - 1 (Civil Services)

 Suckling by the baby stimulates the paraventricular nuclei and supraoptic nucleus in the hypothalamus, which signals to the posterior pituitary gland to produce oxytocin. Oxytocin stimulates contraction of the myoepithelial cells surrounding the alveoli, which already hold milk. The increased pressure causes milk to flow through the duct system and be released through the nipple.

Vaccination is not available for malaria. 

Their size varies from barely a kilometre to a few hundred kilometres.

Kepler

Clove, the commonly used spice, is obtained from the flower bud.

Cell division is performed by all the organisms, be it unicellular or multicellular.

A diver is able to cut through water in a swimming pool because the force of attraction among the particles is less. If the force had been strong, the diver would not have been able to cut that force. Moreover, the particles of water are continuously moving with some kinetic energy (although the magnitude of kinetic energy is not very high). They don’t possess potential energy.

 Hydrogen and helium, the lightest two gases, weigh so little that helium balloons and hydrogen dirigibles are able to float in the atmosphere.

Alloys are used because they have high melting point which ensures that the heating element does not melt upon heating continuously. The element chosen as heating element should be such that it has high resistance because of Joule's law of heating:
Heat is directly proportional to resistance, i.e. more resistance more heat.

 A bird sitting on a high power line is not affected practically as there is no short circuit.

Statement 1 is correct. Holography is a technique, which enables three-dimensional images to be made. It involves the use of a laser, interference, diffraction, and light intensity.
Statement 2 is also correct. Oil or soap film appears coloured due to interference. Thin-film interference is the phenomenon that occurs when incident light waves reflected by the upper and lower boundaries of a thin film and interfere with one another to form a new wave.

Statement 1 is correct. Nicolaus Copernicus is known as the father of modern astronomy.
Statement 2 is incorrect. Galileo Galilee was the first who used the telescope to make detailed studies of heavenly bodies.

Antibiotics are widely produced by both fungi and bacteria.

Statement 1 is correct. MTPS (Mejia Thermal Power Station) is the largest thermal power plant in terms of generating capacity. It is located in West Bengal.
Statement 2 is incorrect. Venus is the hottest planet in the solar system.

The principle underlying a microwave is similar to that used in thermal radiation. A microwave oven does emit thermal radiation to heat up food, which is also called infrared radiation. Microwave radiation is thermal radiation.

The product of force and displacement in the direction of force is known as the work done.
So, work = force x distance 
The unit of force is Newton and the unit of distance is metre. 
Therefore, the unit of work is Newton-metre.

Statement 1 is correct. Yes, lightning produces ozone gas. During lightning, 99% of the gas in contact with sun's corona is converted into ozone.
Statement 2 is also correct. Mars is red because its surface contains a lot of iron oxide or rust.

The cells having nuclear material without nuclear membrane are termed as prokaryotic cells and the organisms with this kind of cells are called prokaryotes.

At resonance, the frequency of the external source becomes equal to the natural frequency of the object and the amplitude of the vibration becomes very large nearly infinite which is responsible for the breaking of the glass. 

 Jet fuel is a clear to straw-colored fuel, based on either an unleaded kerosene (Jet A-1), or a naphtha-kerosene blend (Jet B).

Statement (i) is incorrect. According to law of conservation of energy, ‘Energy can neither be created nor destroyed’.
Statement (ii) is correct. Energy is defined as the ability to do work.
Statement (iii) is also incorrect. Energy measures the ability to do work, while ‘power’ is the time rate at which work is done or energy is transferred.

Statement 1 is wrong. Tungsten is used in the making of filaments of electric bulb.
Statement 2 is correct. Iron is extracted from its ore called haematite.

Statement 1 is correct. Sucralose is an artificial sweetener. The majority of ingested sucralose is not broken down by the body, so it is non-caloric.
Statement 2 is incorrect. Aspirin is used as a blood thinner because of its anti-coagulant property.

 When water boils, it turns into vapors. When the temperature falls on touching the wall, the vapors condense.

It is considered as the blood bank of the body as it removes old worn out red blood cells and keeps in reserve new bood cells and supplies them at the time of blood loss.