Question

2 multiple choice 1 point which of the following is a component of the plasma membrane that creates a physical barrier between the inside and the outside of the cell? water cholesterol proteins phospholipids 3 multiple choice 1 point which of the following describes the plasma membrane? a single - layered membrane that surrounds the nucleus of the cell a membrane composed of tiny shelves or cristae a phospholipid bilayer surrounding the cell a double layer of protein enclosing the plasma

Explanation:

For question 2, the plasma - membrane's main structural component creating a physical barrier is the phospholipid bilayer. Phospholipids have a hydrophilic head and a hydrophobic tail, which arrange themselves to form a barrier. Water is not a structural component of the plasma membrane in this context. Cholesterol modulates membrane fluidity and proteins have various functions like transport and signaling but are not the main barrier - forming component.
For question 3, the plasma membrane is a phospholipid bilayer surrounding the cell. It is not a single - layered membrane around the nucleus (that's the nuclear membrane), not composed of cristae (which are in mitochondria), and not a double - layer of protein enclosing the plasma.

Answer:

1. D. phospholipids
2. C. a phospholipid bilayer surrounding the cell