Desertification refers to the gradual ecosystem degradation, where plants and animals, and geological resources such as water and soil, are stressed beyond their ability to adjust to changing conditions.
Desertification is caused by by various factors such as overgrazing, urbinization, overdrafting of ground water, deforestation, tillage practices and natural disasters among other factors.
<em>Desertification affects the ground water reserves, topsoil, human, surface runoff, animal and plant populations.</em>
Topsoil is usually the riches soil in terms of nutrient is important in support of plant vegetation. It is rich because it contains humus and other decomposed materials that recycle nutrients. When the topsoil is washed away, the local region becomes barren in that it cannot support vegetation. This causes the area to turn into a desert.
It is given that the number of chromosomes present in each onion root tip cell is 16. Hence, the number of chromosomes in the cell will be 16 at G1 phase, after S phase and after M phase
Based on your knowledge of the carbon cycle, what do you think might happen if humans were to continue to clear and burn vast areas of forests for building? Eventually we would run out of forests and the air would be very polluted. Explain how a nutrient can be a limiting factor in an ecosystem.
