Answer:
Myelination
Explanation:
Myelin is a fatty substance composed of lipids which surrounds the axons of the nerve cells in the central nervous system. The myelin is formed by the oligodendrocytes in CNS and Schwann cells in PNS.
The plasma membrane of the oligodendrocytes containing the myelin covers the axons of the neurons in spiral fashion thus proving a sheath around through the process called "myelination".
This myelin sheath protects the neurons from the external environment as well as insulates the neuron which increases the efficiency of the impulse.
Thus, Myelination is the correct answer.
Answer:
Three factors are used.
The availability of sunlight.
The distance from shore and
The water depth.
Explanation:
<u>Availability of Sunlight
</u>
The photic zone is the upper part of the ocean into which sunlight penetrates.
<u>Distance from Shore
</u>
The intertidal zone is the strip of land where the land and ocean meet and overlap, or the zone between high and low tides.
The neritic zone is the marine-life zone that extends from the low-tide line out to the shelf break.
The oceanic zone is the marine-life zone beyond the continental shelf.
<u>Water Depth</u>
The pelagic zone is open zone of any depth. Animals in this zone swim or float freely.
The benthic zone is the marine-life zone that includes any sea-bottom surface regardless of its distance from shore.
The abyssal zone is a subdivision of the benthic zone characterized by extremely high pressures, low temperatures, low oxygen, few nutrients, and no sunlight
Answer:
D. contact metamorphism
Explanation:
When there's a volcanic activity in certain area, very often it happens that there's magma that intrudes into the cold rock in the surrounding area. The intrusion of the hot magma into the cold rock layers causes big changes into the structure of the rocks. The high temperature and high pressure manage to influence the structure of the preexisting rocks, mostly on the places where the magma touches the cold rocks, leading to the formation of metamorphic rocks. This type of metamorphism is known as contact metamorphism.
