Answer:
There are two types of ecological succession:
Primary succession:
Primary succession occurs in areas which were previously devoid of life. There were no organisms living in this area before. For example, lands after new glaciers or volcano eruptions. Firstly, microorganisms begin to habitat this land, followed by plants like lichens, shrubs etc. Finally, complex life evolved from these.
Secondary succession:
Secondary succession arises in areas where life existed before but was destroyed due to natural circumstances like flood, fire etc. Small grasses inhabit this land first which are taken over by trees over period of time.
B.
Deforestation affects ecosystems on land. there are no forests underwater
The cell cycle is controlled by many cell cycle control factors, namely cyclins, cyclin-dependent kinases (Cdks) and cyclin-dependent kinase inhibitors (CKIs). Cyclins and Cdks, which are positive regulators of the cell cycle, activate cell cycle factors that are essential for the start of the next cell cycle phase.
Factors Affecting Cell Division
Nutrients. The nutrients present in the cell affect cell division. ...
Genetics. Genetic code regulates cell division. ...
Chemicals. Exposure to toxic chemicals such as pesticides and some cleaning chemicals can cause cell mutation. ...
Stress. Stress affects cell division.
