A mold was developing in some of the culture dishes used by Sir Alexander Fleming and was eliminating some of the bacterial population. The hypothesis is that the mold was generating a chemical, which was toxic to the bacteria in the dishes and killed them.
The hypothesis was examined by separating the Penicillium and administering it into the solution of nutrient broth. After the growth of Penicillium it was withdrawn from the broth. The broth was then eventually supplemented to the bacteria and the bacteria died. Thus, it can be concluded that the hypothesis is supported.
Answer:
Inhibitory influences from neuroglia, and the absence of growth-stimulating cues.
Explanation:
Neurogenesis in adults is limited by Inhibitory influences from neuroglia, mainly from oligodendrocytes, and the absence of growth-stimulating cues that are present during fetal development. It is so hard to repair a damaged nerve because nerve cell like other cells can't divide and increase in number, they can't renew themselves. Due to no division, the nerve cells does not increase in number and therefore can't repair themselves.
C. The question is hinting at the similarities between how single cellular organisms maintain homeostasis by regulating water levels the same way the kidney does for multi cellular humans.
