Read this essay to learn about the theories on the origin of angiosperms. Theories on the Origin of Angiosperms Essay Contents: Essay on the Isoetes-Monocotyledon Theory Essay on the Conifer-Amentiferae Theory Essay on the Gnetales-Angiosperm Theory Essay on the Bennettitalean Theory Essay on the Caytonialean Theory Essay on the Pteridosperm Theory Essay on the Pentoxylales Theory Essay # 1. Isoetes-Monocotyledon [...]
In this article we will discuss about the origin of cell wall in plants. Initially middle lamella creates a new boundary between the two-daughter nuclei of a dividing cell. The components of cell wall deposit on either side of middle lamella to form the cell wall. In a non-vacuolated cell, nucleus is usually present at the centre where it divides. [...]
Life on earth appeared 500 million years after its formation. Different theories were given by different thinkers and scientists. (i) Theory of Special Creation: It states that God created life by his divine act off creation, i.e., the earth; light; plants and animals are all being created by the supernatural power. This theory has following connotations: (a) All living organisms [...]