Question Discussion & Solution

Concept-

• DNA stands for Deoxyribonucleic acid.
• DNA as an acidic substance present in the nucleus was first identified by Friedrich Meischer in 1869.
• He named it ‘Nuclein’.
• DNA acts as the genetic material in most organisms.
• A DNA molecule consisting of all the genetic material of an organism is known as a chromosome.
• These are thread-like (helical) structures of protein and nucleic acids which​ carry all the genetic information in the form of genes.

Explanation-

• ​Deoxyribonucleic acid (DNA) is a nucleic acid and is therefore made up of nucleotide.
• Each nucleotide consists of a phosphate group, a nitrogenous base (A, T, G, C), and ribose sugar (deoxyribose in case of DNA).
• A nucleoside contains only pentose sugar and a nitrogenous base.
• Deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) are the two types of nucleic acids found in living systems.
• DNA is a long polymer of deoxyribonucleotides.
• The length of DNA is usually defined as the number of nucleotides (or a pair of nucleotides referred to as base pairs) present in it.

Thereby DNA is composed only of nucleic acid.

Additional Information

Lipids: 

• ​These organic compounds are nonpolar molecules, which are soluble only in nonpolar solvents and insoluble in water because water is a polar molecule.
• In the human body, these molecules can be synthesized in the liver and are found in oil, butter, whole milk, cheese, fried foods, and also in some red meats.

Proteins:

• Proteins are composed of amino acids, arranged into different groups.
• These fundamental amino acid sequences are specific and their arrangements are controlled by the DNA. 
• These are the fundamental building blocks of our bodies.
• They are large and complex macromolecules or bio-molecules which perform a major role in the functioning and regulating of our body cells, tissues, and other organs in the human body.​

Concept-

• The transparent curved surface which is used to refract the light and make an image of any object placed in front of it is called a lens.
• The lens whose refracting surface is upside is called a convex lens.
• The convex lens is also called a converging lens.
• The lens having refracting surface inward is called a concave lens.
• The concave lens is also called a diverging lens.

Explanation-

As we can see below, The concave lens is also called a diverging lens.

Hence option 2 is correct among all

The correct answer is In 1994.

• In 1994, the state road policy was announced in Rajasthan.

Key Points

• State road policy, Rajasthan:
  • Rajasthan was the first state in the country to announce a State Road Policy in 1994.
  • The policy formulated the road map to connects places of religious and tourism importance and railway stations.
  • Organizations working in Rajasthan for the development of roads are Rajasthan State Road Development & Construction Corporation Limited, National Highway Authority of India, and Rajasthan State Road Development Corporation.
  • Pratap Singh Khachariyawas is the Transport Minister in the Government of Rajasthan.

Additional Information

• Nitin Gadkari is the Minister for Road Transport & Highways in the Union Government.
  • He is also the Minister of Micro, Small and Medium Enterprises.

The correct answer is Curvature of the lens.

Important Points

• Focal length of a lens depends on its curvature and the medium outside the lens.

Additional Information

• The ability of a lens to converge or diverge light rays depends on its focal length.
  • For example, a convex lens of short focal length bends the light rays through large angles, by focussing them closer to the optical centre.
  • Similarly, the concave lens of a very short focal length causes a higher divergence than the one with a longer focal length.
• The degree of convergence or divergence of light rays achieved by a lens is expressed in terms of its power.
  • The power of a lens is defined as the reciprocal of its focal length.

Option 1 - Arrow - Arrow is used in Archery. An arrow is a projectile with a pointed tip and a long shaft with stabilizer fins (fletching) towards the back, with a narrow notch (nock) at the very end to contact the bowstring.

Option 2 - Duck - In cricket a duck is a batsman's dismissal with a score of zero.

Option 3 - Stump - In cricket, the stumps are the three vertical posts that support the bails and form the wicket.

Option 4 - Pitch - In the game of cricket, the cricket pitch consists of the central strip of the cricket field between the wickets.

All except Arrow is associated with cricket.