Questions

Plantain plant is a herb, because it does not have an aerial stem - what appears as a stem is really the leaves with sheathing bases. As the piant lives for several years it is called perennial herb

A. J . Oparin was the first to propose the origin of life from inorganic chemical atoms like Oxygen, Hydrogen, Nitrogen and Carbon.

In chemistry, a metal is an element that readily forms positive ions (cations) and has metallic bonds. Metals are opaque, lustrous elements that are good conductors of heat and electricity. Most metals are malleable and ductile and are, in general, denser than the other elemental substances.

Examples of metals are aluminium, copper, iron, tin, gold, lead, silver, titanium, uranium, and zinc.

Here Se - Selenium is an element but is not a metal, S - Sulphur is not a metal and I - Iodine is also not a metal.

Hence, Zn - Zinc is the only metal in the given options.

Size of the primary memory of a PC ranges between 256 KB to 640 KB.