answer:
by having a high genetic level of melanin in your skin, you're skin is more protected from the ultra violet sun rays. Darker skinned races have more melanin present, these races originate from hot countries where sunlight is often present; the production of melanin in their skin allows them to reflect and inhibits they're skin from becoming extremely damaged. Light skinned races don't have a large amount of melanin due to they're native countries lacking sunlight. This is an evolutionary adaptation of the human race.
Answer:
2. have no negative particle
Explanation:
Helium atoms contains 2 neutrons and 2 protons (or 2 electrons). Thus, it has a mass number of 4 and atomic number of 2.
Alpha particles are heavy and positively charged, which make them to be deflected in a magnetic or electric charge. So, the helium atoms used as alpha particles for the gold foil experiment must have no negative particle.
Answer:
oligodendrocytes
Explanation:
Glial cells are part of the nervous system. These are helper cells that support the function of the central nervous system (CNS) and can be called oligodendrocytes when they supply myelin to neurons. These cells are responsible for producing the myelin sheath have the function of electrical insulator for CNS neurons. They have extensions that wrap around the axons, producing the myelin sheath.
It is estimated that there are 10 glia cells in the CNS for each neuron, but because of their small size, they occupy half the volume of nervous tissue. They differ in form and function and they are: oligodendrocytes, astrocytes, Schwann cells, ependymal cells, and microglia.
