Which of the following cell structures is non-living?

$I.$ Found only in sporophytic phase of life cycle
$II.$ May contain enzymes that are biologically active
$III.$ Often contain strengthening polymers
Select the correct option for cell wall

What is the middle lamella composed of?

The cell wall in higher plants is primarily composed of which of the following substances?

The non-living, rigid structure surrounding the plasma membrane is:

The internal layer joining the primary walls of the two adjacent cells is known as