Derived demand is an economic term describing the demand for a good/service resulting from the demand for an intermediate or related good/service. It is a demand for some physical or intangible thing where a market exists for both related goods and services in question.

Kharif crops are domesticated plants like rice that are cultivated and harvested in India, Pakistan and Bangladesh during the Indian subcontinent's monsoon season, which lasts from June to November depending on the area. Monsoon rains may begin as early as May in some parts of the Indian subcontinent, and crops are generally harvested from September to October, again depending upon the region and the crops. Rice, maize and cotton are major kharif crops in India.

Potassium permanganate is an inorganic chemical compound and medication. It has the chemical formula KMnO4 and is a salt consisting of K+ and MnO+4 ions. It is a strong oxidizing agent. Potassium permanganate is used extensively in the water treatment industry for the purification of drinking water.

Islets of Langerhans are irregularly shaped patches of endocrine tissue located within the pancreas of most vertebrates. The alpha cells of the islets of Langerhans produce an opposing hormone, glucagon, which releases glucose from the liver and fatty acids from fat tissue. In turn, glucose and free fatty acids favour insulin release and inhibit glucagon release.

When light rays enter the human eye, the curved surfaces bend them. This process is called refraction. Bending the light rays is necessary in order to focus an external object's image and emit the light just behind the lens, at an area called the focal point. The image is then focused on the retina and the nature of the image formed is real and inverted.

Isotopes are one of two or more species of atoms of a chemical element with the same atomic number and position in the periodic table and nearly identical chemical behaviour but with different atomic masses and physical properties. Every chemical element has one or more isotopes.

Agrology is the branch of agriculture that deals with the origin, structure, analysis, and classification of soils especially in their relation to crop production. It is the practice of bioresource sciences to provide knowledge and advice to support the development of the agriculture sector and the health of the society, environment, and economy.

Euglena is a genus of Kingdom Protista. It is the best known and most widely studied member of the class Euglenoidea. Most species of Euglena have photosynthesizing chloroplasts within the body of the cell, which enable them to feed by autotrophy, like plants. However, they can also take nourishment heterotrophically, like animals. Thus, Euglena has features of both animals and plants.

Nitrification is the biological oxidation of ammonia or ammonium to nitrite followed by the oxidation of nitrite to nitrate. The transformation of ammonia to nitrite is usually the rate limiting step of nitrification. Nitrification is an important step in the nitrogen cycle in soil.

The Sella turcica is located in the sphenoid bone behind the chiasmatic groove and the tuberculum sellae. It belongs to the middle cranial fossa. The most inferior portion of the sella turcica is known as the hypophyseal fossa, and contains the pituitary gland.