In goats, a recessive gene causes the goats to "faint" when they are startled. A farmer has a goat that is a carrier for the fainting gene (Gg). Gertrude is mated with one that is homozygous dominant. How many of their offspring will be
fainters?

oxygen and carbon dioxide

Explanation:

Small, uncharged substances such as oxygen and carbon dioxide can pass through the membrane by diffusion, down their concentration gradient.

Larger molecules or charged molecules cannot easily diffuse through the plasma membrane, and require the help of proteins to get into and out of the cell.

Organelles are relatively large molecules, and likely need a process called endocytosis to pass through the cell membrane into the cell, or exocytosis to pass through the membrane outside of the cell.

Endocytosis and exocytosis rely on membrane-bound vesicles to move substances across the membrane to their destination.