Answer:A selectively permeable cell membrane is one that allows certain molecules or ions to pass through it with active or passive transport.
Explanation:
Answer:
D) movement of the tectonic plates.
Explanation:
Lets understand first what convection is. It refers to the process through which denser material sinks and less dense material rises. This is because less dense material is more buoyant than denser one.
The earth is composed of water, rocks and air and all these things lower their density when there occurs an increase in their temperature.
So what happens when convection occurs in the upper mantle of earth, it raises the less dense material called magma in uprising direction, because of the extreme heat in the Earth’s core. When molten lava moves upwards it moves in a fashion of convection, but then it cools down and sinks again.
As the earth surface is made up of tectonic plates. Scientists believe that when convection occur in mantle layer, it causes the movement of plates, This movement can be away from, or towards each other. The movement of tectonic plates causes shifts continents, ocean basins, earthquakes and pushes up mountains.
So D is best option.
Hope it helps!
I guess the answer is A,it may help you
Answer:
The CNS
Explanation:
First, the entire CNS is enclosed in bone. The brain is protected by the skull, while the spinal cord is protected by the vertebra of the spinal column. The brain and spinal cord are both covered with a protective tissue known as meninges.
