The respiratory and circulatory systems work with each other in this manner, the respiratory system will obtain oxygen then the circulatory system brings the oxygen to different parts of the body then it also takes carbon dioxide from different tissues of the body and bring carbon dioxide to lungs then the respiratory system takes carbon dioxide outside the body during exhalation
RAS is a very important protein that belongs to a class of protein referred to as GTPases and plays a crucial role in switching on pathways that control cell growth, proliferation, apoptosis and differentiation and migration. For RAS to become inactive it must hydrolyze GTP to GDP which slows down the process of cell proliferation. Mutation in one copies of RAS will result to cancer because the mutated copy will permanently attach to GTP and remain in activated form which will lead to uncontrollable cell division and hence development of cancer.
Answer:
D: tidal effects of the Moon
Explanation:
C. ferns.
Explanation:
The ferns are ancient plants that have managed to survive until the present. They are not closely related to the dominant plants nowadays, the flowering plants, but instead they are closely related with plants that have gone extinct tens and hundreds of millions years ago. Even though the ferns are not the dominant plants, they have managed to find a niche and firmly hold onto it, so they remained widespread, normally occupying the lower layers of the forests.
Unlike the flowering plants that produce flowers and then seeds in order to reproduce, that is not the case with the ferns. The ferns actually reproduce through spores, being widely dispersed by the wind and managing to spread out and reproduce over relatively large territory very quickly.
