According To definition of Lichens: Lichens are symbiotic associations of a fungus with the photosynthetic partner called as phycobiont such as green algae or cyanobacteria.gain, The two organisms live in close association with each other and both get benefit from this kind of association, this is called Symbiotic Association. By the way, Parasitic relation means living in or on another organism (host) and causing harm to it.
The White Nile (Arabic: Ø§ÙÙÙÙ Ø§ÙØ£Ø¨ÙØ¶ââ an-nÄ«l al-'abyaá¸) is a river in Africa, one of the two main tributaries of the Nile; the other is the Blue Nile. In the strict meaning, White Nile refers to the river formed at Lake Victoria, at the confluence of the Bahr al Jabal and Bahr el Ghazal Rivers.
It is 6,853 km (4,258 miles) long. The Nile is an international river as its water resources are shared by eleven countries, namely, Tanzania, Uganda, Rwanda, Burundi, Congo-Kinshasa, Kenya, Ethiopia, Eritrea, South Sudan, Sudan and Egypt. In particular, the Nile is the primary water source of Egypt and Sudan.The Nile has two major tributaries, the White Nile and Blue Nile. The White Nile is considered to be the headwaters and primary stream of the Nile itself. The Blue Nile, however, is the source of most of the water and silt.bove Khartoum the Nile is also known as the White Nile, a term also used in a limited sense to describe the section between Lake No and Khartoum. At Khartoum the river is joined by the Blue Nile.