NEET BIOLOGY

Detailed explanation-1: -The Sahel is a narrow band of semi-arid land that forms a transition zone between the Sahara to the north and the savannas to the south.

Detailed explanation-2: -The Sahara stretches across much of northern Africa creating a formidable barrier and dividing Africa between a Muslim, Arab North and traditional African cultural groups in the south.

Detailed explanation-3: -Physiography. The principal topographical features of the Sahara include shallow, seasonally inundated basins (chotts and dayas) and large oasis depressions; extensive gravel-covered plains (serirs or regs); rock-strewn plateaus (hammadas); abrupt mountains; and sand sheets, dunes, and sand seas (ergs).

Detailed explanation-4: -Subsaharan Africa is a realm of plateaus and basins with four main river systems. Mountain ranges, volcanic peaks, and large lakes are found in or along the rift valleys of eastern Africa. The rift valleys were created by tectonic activity.