Aforest fire burns down most of the trees in a large forest l. the animals that live in the trees are forced to move to other areas. what kind of disturbance is this? a. cyclical b. small c. primary d. secondary

Answer is D , Secondary

Explanation:

An example of Secondary Succession by stages:

1. A are of growth 2. A disturbance, such as a fire, destroys the forest

3. The fire burns the forest to the ground

4. The fire leaves behind empty, but not destroyed soil

5. Grasses and other herbaceous plants grow back first

6. Small bushes and trees begin to colonize the public area

7. Fast growing evergreen trees and bamboo trees develop to their fullest, while shade-tolerant trees develop in the understory

8. The short-lived and shade intolerant evergreen trees die as the larger deciduous trees overtop them. The ecosystem is now back to a similar state to where it began.

In homeostasis fashion, cells undergo balanced cell division and programmed cell death (apoptosis) through regulated signalling.This maintains tissue integrity. On the one hand, Proto-oncogenes promotes cells proliferation. On the other hand, tumors suppressors inhibit cell growth and division especially in cells with damaged dna.
Therefore mutations on these oncogenes could result to uncontrolled cell proliferation. Cancer cells also overexpress angiogens that results to proliferation of blood vessels in tumors. This contributes to their metastasis in the body.