Answer:
False
Explanation:
Scientist believe that the primitive atmosphere lacked free oxygen. Oxygen is a highly reactive molecule that would have made difficult for complex macromolecules to appear and then create life. Rocks from the precambrian period support this theory.
Anaerobic cells appeared first, then photosynthesis appeared filling the atmosphere with oxygen and the aerobic organism develop cellular respiration to obtain energy, a process more efficient than anaerobic respiration.
The answer is vitamin D. This is actually a group of vitamins of similar molecular structure responsible for facilitating increased absorption of calcium, magnesium and phosphate from the gut. The most important of the vitamin D compounds are vitamin D3 and D2. While vitamin D can be obtained from your diet and supplements, the major source of vitamin D is from a chemical reaction dependent on skin exposure to the sun.
<span>Mitosis is carried out for growth and development processes. The cell divide and multiply for growing and removing the worn out cells/damaged cells. Two identical daughter cells are formed in mitosis. Errors in the same may cause genetic disorders, Sex cells divide by the process of meiosis. </span>
Growth and development
Reproduction
Maintains homeostasis
Has cells
Metabolism
Heredity
Responds to stimuli
Adapts to environment