All High School Biology Resources
Example Questions
Example Question #51 : Common Cell Structures
Which of the following are true of cell walls?
They provide support and protection for the cell
They are made of lipids
They are made only of carbohydrates
They are a double layer of phospholipids
They provide support and protection for the cell
The cell wall provides support and protection for the cell. Most are made from carbohydrate and protein. They are not made of phospholipids or lipids.
Example Question #11 : Understanding The Cell Membrane And Cell Wall
Which of the following is another name for the cell membrane?
Semipermeable membrane
Phospholipid bilayer
All of these
Cytomembrane
Plasma membrane
All of these
All these answers are correct and can be used interchangeably, so it's good to be aware of all of them. All cells have a cell membrane, regardless of organism, to separate their internal environment from their external environment. The term plasma membrane refers to the cytoplasm within the cell that the membrane is separating from the external environment. Phospholipid bilayer describes the molecular makeup of the cell membrane as it is composed of a double layer of amphiphilic (something that is both hydrophobic/lipophilic and hydrophilic) phospholipids. Semipermeable membrane refers to the ability of the membrane to allow certain substances cross from one side to the other, while restricting the passage of other substances. Cytomembrane uses the Greek root "cyto", meaning cell, to create a compound word that in the end means the same thing as cell membrane.
Example Question #12 : Understanding The Cell Membrane And Cell Wall
The major component of cell membranes is __________.
phospholipids
starch
glucose
amino acids
galactose
phospholipids
Cell membranes are composed of a phospholipid bilayer. Phospholipids have hydrophilic heads and hydrophobic tails. The tails come together to form the hydrophobic inside of the membrane, whereas the hydrophilic heads face the outside of the cell and the inside aqueous cytoplasm.