Answer:
Metamorphic rocks are almost always harder than sedimentary rocks. They are generally as hard and sometimes harder than igneous rocks. They form the roots of many mountain chains and are exposed to the surface after the softer outer layers of rocks are eroded away.
Because their mineral grains grew together tightly during metamorphism, they're generally strong rocks.
Answer:
B) astrocytes
Explanation:
Cells other than neurons that play an important role in the normal functioning of nervous system are called Neuroglia or glial cells.
Satellite cells, astrocytes, schwann cells and oligodendrocytes are all examples of glial cells.
⇒Satellite cells provide protection and nutrition to cells in peripheral nervous system ( peripheral nerves and ganglia).
⇒<em><u>Astrocytes</u></em> play an important role in central nervous system (brain and spinal cord). They provide protection to neurons, scavenge ions, form the blood-brain barrier and also maintain extracellular environment suitable for neuronal functioning.
⇒Schwann cells are found in the peripheral nervous system and myelinate the axons of neurons.
⇒Oligodendrocytes are found in central nervous system and produce myelin sheath which myelinates (insulates) axons of neurons. Their function is similar to schwann cells but in the central nervous system.
From the above discussion it is clear that the answer is B) Astrocytes as these maintain a suitable chemical environment for the neurons.
I would wait for a second opinion, because the question is phrased in such a way that is confusing.
None of the statements contain scientific evidence except for the last one, but the last statement is false.
If you were being scientifically accurate, you would answer the first statement as true and the rest false.
The second statement actually has evidence to back it up, but the evidence provided is incorrect.
