Science - 3 (Gen. Studies)

Neurospora crassa is a red bread mold. It is used as a model organism because it is convenient to grow and has a haploid life cycle that makes genetic analysis easier since recessive traits will come in the progenies.

It is caused due to bacteria.

Correct Answer: Tuberculosis usually spreads through milk.

 DPT provides vaccine against diphtheria, pertussis and tetanus.

Mars is called the 'Red Planet' due to its reddish appearance caused by iron oxide (rust) on its surface. Jupiter (A) is the largest planet with bands, Saturn (B) is known for its rings, and Venus (D) appears white/yellow.

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

Mayer coined the term as 'histology'.

Beta-carotene is found in plants that gives them their colour. 

Correct answer is (4).

It shows the record of species (all plants and animals) at the risk of extinction. The IUCN maintains this book to provide data on population status of species around the world.

When we pour some acetone (nail polish remover) on our palm, we feel cool. This is because particles gain energy (equal to latent heat of vapourisation) from our palm or surroundings and evaporate, causing the palm to feel cool. the palm will not get heated. It will not become red and it will not pain as nail polish remover does not harm our skin.

 Pitchblende is an ore of uranium.

Though thunder and lightning occur together, we first see the lightning and hear the thunder after some time.

Rectifiers are circuits made of diodes and are used to convert AC to DC. 

(I) Statement (1) is wrong. If an object is placed midway between two parallel plane mirrors facing each other, the number of images that appear in the mirrors is infinity.
(II) Statement (2) is correct. Magnifying glass is made of a converging lens which helps to produce an upright and magnifying image of an object.
(III) Statement (3) is wrong. To get a virtual and magnified image, concave mirror is used.

Statement (1) is wrong. Rug or carpet acts as an insulator. It does not conduct the heat of the floor to the feet.
Statement (2) is correct. Convection is the flow of heat through a bulk, macroscopic movement of matter from a hot region to a cool region.

Statement (1) is correct. The molecules of solids have the maximum force of attraction among them. For the conversion of solid into liquid, the given heat is used to break the strong bonds between them.
Statement (2) is also correct. Iron rod is heavier because the space between the particles of iron is very less, comparatively to the space between the particles of chalk.

Statement (1) is correct. Frogs undergo both pulmonary (through lungs) and cutaneous respiration (through skin).

Manometer is used for measuring fluid pressure.

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 water stored in a dam possesses only potential energy.
It does not have kinetic energy since stored water has zero velocity, i.e. kinetic energy is the wrong option.

Statement (1) is incorrect. Power is the amount of work done in a unit of time. Hence, its unit is Watt = J/s. 
Statement (2) is correct. Work is always related to the displacement of body in the action of applied force.
Statement (3) is correct. ‘Energy’ refers to the capacity to do work.

DNA is present in every cell of a body.
So, any of the hair root cells, saliva or white blood corpuscles can be taken as the sample for DNA fingerprinting.

Small intestine is divided into 3 parts; Duodenum, where secretion of liver and pancreas are poured in; Jejunum, where intestinal juice completely digests all food particles; and Ileum, where digested food is absorbed into the blood. Colon is a part of the large intestine. Hence, (4) is the answer.

Correct Answer: Sodium thiosulphate

Nerve cell is the longest cell, whereas ostrich egg is the largest cell.

Potassium permanganate acts as oxidizing agent (release oxygen) in the drinking liquid.
Hence, it increases the purification level by adding oxygen into it.

Statement (1) is correct. Non-metals are bad conductors of electricity, but the only exception is graphite, which is a good conductor of electricity.
Statement (2) is correct. Gauge is the impurities, which are present in the ores of metal. The various extraction methods are used for the removal of gauge to get the pure metals.

Vulcanisation is the chemical process of heating rubber with sulphur to improve its properties - making it harder, more durable, and more elastic. Sulphur forms cross-links between rubber polymer chains. This process was discovered by Charles Goodyear and revolutionized rubber industry.

According to ECO GO, cornstarch packaging helps reduce the millions of tonnes of plastic waste that accumulate every year. Cornstarch products are made mainly from cornstarch with blending and polymerising with aliphatic materials (such as PLA, PHBV and PCL). This cornstarch packaging is biodegradable within 72 days and all degradable components can decompose in 180 days.