Question

cell transport quiz

1. what is the main function of the cell membrane?

a. to produce energy for the cell
b. to control what enters and leaves the cell
c. to store genetic material
d. to make proteins

1. the cell membrane is also known as the:

a. cytoplasm
b. nuclear membrane
c. plasma membrane
d. cell wall

1. the cell membrane is described as a phospholipid bilayer because:

a. it is made of one layer of carbohydrates
b. it has two layers of lipids with proteins embedded
c. it is made of protein only
d. it has no lipids

1. what does it mean that the cell membrane is semi - permeable?

a. it allows all materials to enter
b. it allows no materials to enter
c. it allows only some substances to pass through
d. it completely blocks all materials

1. which statement about phospholipids is true?

a. the head is hydrophobic and the tails are hydrophilic
b. both head and tails love water
c. the head is hydrophilic and the tails are hydrophobic
d. both head and tails hate water

1. the movement of molecules from high concentration to low concentration without using energy is called:

a. active transport
b. diffusion
c. endocytosis
d. exocytosis

Explanation:

1. The cell membrane's main function is to control substances' entry and exit.
2. The cell membrane is also called the plasma membrane.
3. The phospholipid bilayer has two lipid layers with embedded proteins.
4. Semi - permeable means only some substances can pass.
5. Phospholipid heads are hydrophilic, tails are hydrophobic.
6. Diffusion is movement from high to low concentration without energy.

Answer:

1. B. To control what enters and leaves the cell
2. C. Plasma membrane
3. B. It has two layers of lipids with proteins embedded
4. C. It allows only some substances to pass through
5. C. The head is hydrophilic and the tails are hydrophobic
6. B. Diffusion