A river delta is a landform that forms from deposition of sediment carried by a river as the flow leaves its mouth and enters slower-moving or standing water. This occurs where a river enters an ocean, sea, estuary, lake, reservoir, or (more rarely) another river that cannot transport away the supplied sediment.Despite a popular legend, this use of the word delta was not coined by Herodotus.his alluvium builds up to form the river delta. When the flow enters the standing water, it is no longer confined to its channel and expands in width. This flow expansion results in a decrease in the flow velocity, which diminishes the ability of the flow to transport sediment.
All the different types of sex cells undergo meiosis while mitosis only occurs in no sex cells or what is known as somatic cells. Spermatozoa and ova (also known as gametes) are the two most important types of cells that undergo mitosis and meiosis.
Mitosis occurs only in eukaryotic cells and the process varies in different organisms. For example, animals undergo an open mitosis, where the nuclear envelope breaks down before the chromosomes separate, while fungi undergo a closed mitosis, where chromosomes divide within an intact cell nucleus.he process of mitosis is divided into stages corresponding to the completion of one set of activities and the start of the next.