The epidermis cells, meaning "over-skin", is a single-layered group of cells that covers plants' leaves, flowers, roots and stems. It forms a boundary between the plant and the external environment. 
The plant epidermis consists of three main cell types: pavement cells, guard cells and their subsidiary cells that surround the stomata and trichomes, otherwise known as leaf hairs. Stomata are holes in the plant epidermis that are surrounded by two guard cells, which control the opening and closing of the aperture. These guard cells are in turn surrounded by subsidiary cells which provide a supporting role for the guard cells.

Osteocytes are the most abundant cells in bone, comprising more than 90% of cells within the matrix or on the bone surfaces. Osteocytes are the most abundant cell type of bone, representing 95% of all bone cells in skeletally mature adult bone tissue¹. The definition of an osteocyte is descriptive of its location (cells surrounded by mineralized matrix), not its function.

An allosome (also referred to as a sex chromosome, heterotypical chromosome, heterochromosome, or idiochromosome) is a chromosome that differs from an ordinary autosome in form, size, and behavior.

In the nucleus of each cell, the DNA molecule is packaged into thread-like structures called chromosomes. Each chromosome is made up of DNA tightly coiled many times around proteins called histones that support its structure.

The type of root formed in Betel vine is Climbing Root. Climbing roots arising from nodes attach themselves to some support and climb over it; other example: money plant.

Cardiac muscle is an involuntary striated muscle tissue found only in the organ heart. Involuntary muscles are smooth muscles that are not directly controllable at will. Voluntary muscles are controllable like those found in arms, legs, hands, etc. Hence Heart is devoid of Voluntary muscle.

Endemism is the ecological state of a species being unique to a defined geographic location, such as an island, nation, country or other defined zone, or habitat type; organisms that are indigenous to a place are not endemic to it if they are also found elsewhere. The extreme opposite of endemism is cosmopolitan distribution. Another term for a species that is endemic is precinctive, which applies to species (and sub specific categories) that are restricted to a defined geographical area. A native species, such as a native plant, is one that is considered to have been endemic for a relatively long period of time.

Uracil is one of the four nucleobases in the nucleic acid of RNA that are represented by the letters A, G, C and U. The others are adenine (A), cytosine (C), and guanine (G). In RNA, uracil binds to adenine via two hydrogen bonds.

Excretion is the process by which waste products of metabolism and other non-useful. Birds excrete their nitrogenous wastes as uric acidin the form of a paste. Hence Sparrow excretes uric acid as its excretory product.

Ringworm is common disease, especially among children. It is caused by a fungus. It is a common and highly infectious skin infection that causes a ring like red rash on the skin.