There are many internal factors which living organisms respond to, two of them are temperature and hormone levels. Organisms respond to internal factors in order to stay healthy and survive. The internal environment of living organisms has to be kept relatively constant, this is constancy is achieved through the process of homeostasis.
The membrane also plays a vital function in preventing things from getting in or leaving the cell, and the second major function is that it is a factor in cell communication and cell recognition.
B) Meiosis-"a type of cell division that results in four daughter cells each with half the number of chromosomes of the parent cell, as in the production of gametes and plant spores." taken from google
