Answer: T
Explanation:Carbon dioxide is added to the atmosphere naturally when organisms respire or decompose (decay), carbonate rocks are weathered, forest fires occur, and volcanoes erupt. Carbon dioxide is also added to the atmosphere through human activities, such as the burning of fossil fuels and forests and the production of cement.
The myelin sheath is the protective layer, which is present in the outer layer of the neural cells. This myelin sheath prevents the loss of electrical impulses, which are being conducted in the neurons. This also act as an insulator between neuron and its external environment.
This layer is mainly made up of the protein and fatty substance. The degeneration of the myelin sheath result in many neurological disorders.
Hence, the correct answer is myelin sheath.
Flagella are hairlike parts that push a bacterium through water or other liquids.