AP BIOLOGY

Detailed explanation-1: -Diffusion is a passive process which means it does not require energy. Small particles diffuse faster than large ones. Eg substances like oxygen, carbon dioxide and glucose move in and out of cells by diffusion. The greater the difference in concentration, the faster the rate of diffusion.

Detailed explanation-2: -Oxygen diffuses through the cell membrane and is transported in blood plasma by free diffusion and by convection.

Detailed explanation-3: -Diffusion is an essential process in cells. They need glucose and oxygen for respiration, which move into them by diffusion. Respiration produces carbon dioxide and water which leave cells by diffusion.

Detailed explanation-4: -Oxygen moves by diffusion from an area of higher concentration inside the lungs to an area of lower concentration in the blood. It is then carried away by red blood cells. The blood leaving the lungs now has a high concentration of oxygen. It travels round the circulatory system to the cells in tissues and organs.

Detailed explanation-5: -Oxygen is diffusing from the air inside the alveoli within the lungs into the erythrocytes and blood plasma. Diffusion is a type of passive transport, where molecules move from high concentration to low concentration. This means that the concentration of oxygen in the air must be higher than it is in the blood.