Xylem, phloem and water uptake — return questions

1. state

State the functions of (a) xylem and (b) phloem.

(a) Xylem

(b) Phloem

2. sequence

Put the steps of the celery dye investigation in order.

Write the number of each step in order.

1. Cut a fresh end on four matched stalks.
2. Stand three stalks in red dye and one in plain water.
3. Take out a different stalk at each time.
4. Cut thin slices across each stalk at measured heights.
5. Look at the slices with a hand lens and record where the red is.

• First: ______
• Second: ______
• Third: ______
• Fourth: ______
• Last: ______

3. complete

Complete the sentences about the stem of a non-woody dicotyledonous plant.

The vascular bundles are arranged in a … near the outside of the stem.

In each bundle the phloem is towards the … of the stem.

In each bundle the xylem is towards the … of the stem.

4. complete

Supplement. Complete the sentences about the structure of a xylem vessel.

The walls of a xylem vessel are thick and strengthened with … .

A finished vessel has no … , so nothing inside blocks the water.

Its cells are joined end to end with no … , so it is one long, continuous tube.

5. state

(a) State the two functions of root hair cells. (b) State how the root hairs increase how much the root takes up.

(a) Functions

(b) How root hairs increase uptake

6. complete

Complete the pathway of water through a plant.

Root hair cells → … →

… → mesophyll cells

7. identify

Which statements about where xylem and phloem are found are correct? Choose all that apply.

Tick every correct statement.

• In a root, the xylem is in the middle.
• In a root, the phloem is between the arms of the xylem.
• In a leaf vein, the xylem is towards the upper surface.
• In a stem, the xylem is on the outer side of each bundle.
• In a leaf vein, the phloem is towards the upper surface.
• In a root, the bundles form a ring near the outside.

8. define

Supplement. Define translocation.

9. classify

Supplement. Which of these are sinks? Choose all that apply.

Tick every correct statement.

• A growing root tip
• A ripening fruit
• A full-grown leaf in sunlight
• A developing seed
• A potato tuber sprouting in spring
• An opening flower bud

10. explain

Supplement. Explain why a potato tuber can be a sink at one time and a source at another.