Which of the following statements about the primary wall is FALSE?

a. It is deposited before and during cell growth.
b. It may contain lignin, suberin, or cutin.
c. Actively dividing cells have only primary walls.
d. Some mature plant cells have only a primary wall.
e. It is usually of uniform thickness.

It is usually of uniform thickness. (Ans. E)

Explanation:

In the plant cell wall primary cell wall is existing between the mid lamella and the secondary cell wall. The structure of the primary cell wall is thin, and flexible in nature and they are made up of pectin, hemicellulose, cellulose.

The primary cell wall is the part of the cell wall that has the capability to enlarges the layers by the mechanism known as an acid growth mechanism, with the help of this mechanism plant cells grow via plant cell wall enlargement at a poor pH level.

when you breathe in, or inhale, your diaphragm contracts (tightens) and moves downward. this increases the space in your chest cavity, into which your lungs expand. the intercostal muscles between your ribs also enlarge the chest cavity. they contract to pull your rib cage both upward and outward when you inhale.

the answer is d. embryo