Oxygen and carbon dioxide pass through the plasma membrane by facilitated diffusion or passive diffusion

The correct answer is option - passive diffusion

Explanation:

Diffusion is the movement of the substance molecules from a high concentration to low concentration region. It can be through carrier proteins or protein channels or without any help. The movement through the channels or carriers is termed as facilitated diffusion and diffusion without any help is known as passive diffusion.

The movement of the carbon dioxide and oxygen move through the passive diffusion as oxygen is non polar it does not need anything to move. Carbon dioxide is polar molecule but very small in size so they also move through passive diffusion.

Thus, the correct answer is option - passive diffusion.

the element that provides strength to the exoskeletons of clams and oysters is phosphorus.

this is so because calcium carbonate is the main component in the shells. calcium carbonate is strengthened by phosphorus.

explanation:

it creates acid rain