Chapter 9 Plant Physiology

Xylem tissue is composed of which two types of cells

• Xylem vessels and companion cells

• Xylem vessels and sieve tubes

• Tracheids and sieve tubes

• Xylem vessels and tracheids

The walls of xylem tissue are reinforced with

• Concrete

• Lignin

• Starch

• Glucose

What is the function of companion cells in phloem?

• To produce lignin

• Control and maintain the sieve tube

• Control movement of water in the tracheids

The purpose of the palisade layer in the leaf is to carry out

• Gaseous exchange

• transpiration

• respiration

• photosynthesis

Nutrients are absorbed by the root hairs by

• Osmosis

• Diffusion

• Active transport

• None of the above

What is the function of Xylem

• To transport food

• To transport lignin

• To transport water

What is the function of phloem

• To transport food/sugar

• to transport lignin

• To transport water

Osmosis is a form of transport that requires energy

• True

• False

Active transport requires energy

• true

• false

The opening and closing of stomata are regulated by

• Guard cells

• Xylem vessels

• Starch

• Lignin