C human selection is the answer hope this helps
Answer:
The air at the equator is warmer and less dense and the air at the polls is cooler and more dense
Explanation:
air at the equator is constantly warm, has denser air, and barely cools and the polar regions are cooler therefore that means it is dense
<span>the young of a viviparous animal, especially of a mammal, in the early stages of development within the womb, in humans up to the end of the second month.
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Cell membrane protects animals cells from harmful chemicals.
Explanation:
The cell membrane is a tough covering composed of the phospholipids and proteins and forms a bilayer around the cells. This acts as a semi-permeable membrane and controls the transport of ions, organic molecules and solutes to and from the cell through selective permeability.
The hydrophilic and hydrophobic properties and the corresponding polarity of the cell membrane and ionization status of the chemicals prevent the entry of harmful substances into the cell. The cell membrane functions as a barrier system and prevents the flow.