A-level Biology Xylem Tissue

What is the primary function of xylem vessels in plants?

• Transport of sugars

• Transport of water and ions

• Photosynthesis

• Storage of nutrients

What substance impregnates the secondary wall of xylem vessels?

• Cellulose

• Starch

• Lignin

• Protein

Why are mature xylem vessels considered dead?

• They lack chlorophyll

• They are impermeable to water

• They do not conduct photosynthesis

• They have no cell contents

What pattern of lignification is found in protoxylem?

• Reticulated

• Pitted

• Annular or spiral

• Uniform

Where is protoxylem typically located in a plant?

• In the mature parts of the plant

• In the growing regions behind the root and shoot tips

• In the leaves

• In the flowers

What pattern of lignification is found in metaxylem?

• Annular

• Spiral

• Reticulated or pitted

• Uniform

What is the function of pits in pitted xylem vessels?

• To store water

• To allow rapid movement of water and ions out of vessels

• To conduct photosynthesis

• To support the plant structure

What is the role of lignin in xylem vessels?

• To provide flexibility

• To conduct photosynthesis

• To provide structural support and impermeability to water

• To store nutrients

Which type of xylem vessel is thickened by interconnecting bars of lignin?

• Annular

• Spiral

• Reticulated

• Pitted

In which part of the plant is metaxylem typically found?

• In the growing regions behind the root and shoot tips

• In the mature parts of the plant

• In the leaves

• In the flowers