Pericardiectomy is the surgical removal of part or most of the pericardium. This operation is most commonly done to relieve constrictive pericarditis or to remove a pericardium that is calcified and fibrous.

The presynaptic membrane is first depolarised, stimulating the release of acetylcholine, the transmitter substance. This diffuses to the postsynaptic membrane, propagating the nervous stimulus. Acetylcholine is then hydrolysed.

A pair of external nostrils present in humans opens out above the upper lip.

Like other tetrapods, humans have two external nostrils (anterior nares) and two additional nostrils at the back of the nasal cavity, inside the head (posterior nares, posterior nasal apertures or choanae). They also connect the nose to the throat (the nasopharynx), aiding in respiration.

A light-year is a unit of Distance.

A light-year, alternatively spelled lightyear, is a large unit of length used to express astronomical distances and is equivalent to about 9.46 trillion kilometers.

Storing carbohydrates in the form of polysaccharides condenses the bulk to be stored, in a relatively easier form, and can be broken down by enzymes whenever energy is required.

The magnitude of acceleration of a moving body is equal to the gradient of a velocity-time graph.

Corpus luteum is the yellow endocrine body formed in the ovary at the site of a ruptured Graafian follicle, while macula lutea is a yellow spot on the retina. The common feature between the two is that both (corpus luteum and macula lutea) are characterized by yellow colour.

The swamp deer Rucervus duvaucelii is the largest grassland-dwelling endemic cervid of India and Nepal. With a declining population trend across its range, this species is found in fragmented habitats of northern, north-eastern and central India and south-western Nepal.

Flora is all the plant life present in a particular region or time, generally the naturally occurring native plants. The corresponding term for animal life is fauna.  

The Pachmarhi Biosphere Reserve is a non-use conservation area and biosphere reserve in the Satpura Range of Madhya Pradesh state in central India. It was created in 1999 by the Indian government.  

Fauna of the Pachmarhi Biosphere Reserve are: leopard, blue bull, barking deer, etc.

A gene whose expression helps in identification of transformed cells is known as selectable marker.

Selectable markers: These are specific gene sequences present in a cloning vector. These genes have certain phenotypic expressions that help in selecting transformed cells.

Example: Ampicillin resistance (amp^R) gene and Tetracycline resistance (tet^R) gene in pBR322 plasmid.

When a DNA fragment is inserted into any one of the selectable marker genes, it causes insertional inactivation of that gene.