Answer: D) Chloroplasts Explanation: Photosynthesis takes place inside plant cells in small things called chloroplasts. Chloroplasts contain a green substance called chlorophyll and this absorbs the light energy needed to make photosynthesis happen.

Answer: B) Proton Explanation: Protons carry a positive electrical charge, electrons carry a negative electrical charge and neutrons carry no electrical charge at all. The protons and neutrons cluster together in the central part of the atom, called the nucleus, and the electrons 'orbit' the nucleus.

Answer: B) chitin Explanation: Many carbohydrates contain one or more modified monosaccharide units that have had one or more groups replaced or removed.   Chitin is one of many naturally occurring polymers. It is one of the most abundant natural materials in the world. Over time it is bio-degradable in the natural environment. Its breakdown may be catalyzed by enzymes called chitinases, secreted by microorganisms such as bacteria and fungi, and produced by some plants.   Chitin is composed of repeating units of N-acetylglucosamine, a nitrogen-containing form of glucose.

You will get the answer in the riddle itself, if you read the riddle carefully. The riddle says "A cowboy arrives in town on Friday." So Friday is the name of the horse on which he comes. Hence, the only possibility is he arrives on the horse friday on Tuesday, stays for 3 days and leaves on the same horse on Friday.

Answer: D) M.Visweswariah Explanation: M.Visweswariah is known as the Father of Indian Engineering.   Father of Indian Printing - James Hickey Father of Indian Green Revolution - Dr. M.S. Swaminathan Father of Indian Painting - Nandalal Bose.

Answer: B) Bombay and Thane Explanation: India's first passenger train run took place from Mumbai to Thane for around 34 kms on 16th April in the year 1853.  That train was hauled by three steam locomotives : Sahib, Sindh and Sultan. That train had 14 carriages, carrying around 400 passengers.

Answer: C) peptide bonds Explanation:

Answer: A) 256 kb to 640 kb Explanation: Size of the primary memory of a PC ranges between 256 KB to 640 KB.