EVERYDAY SCIENCE

Detailed explanation-1: -In particular, organelles called chloroplasts allow plants to capture the energy of the Sun in energy-rich molecules; cell walls allow plants to have rigid structures as varied as wood trunks and supple leaves; and vacuoles allow plant cells to change size.

Detailed explanation-2: -Secondary cell walls contain additional components, such as lignin, which is hard and occupies the interstices between the other components, making the walls rigid and permanent.

Detailed explanation-3: -Cellulose makes the cell wall of plant cells rigid.

Detailed explanation-4: -Biology definition: A cell wall is a structural layer next to the cell membrane with the primary role of giving the cell rigidity and protection from mechanical stress.