Aidan Gill, Heidi Foxford and, Dorothy Warren Solutions for Chapter: Respiration and Circulation, Exercise 4: Exercise 4

The stem of a plant contains xylem tubes. Name two substances transported in the xylem.

Pierre puts the stem of a white flower in a pot of red food colouring mixed with water. After 24 hours the white flower turns pink. Explain why.

Xylem cells have thick walls stiffened with lignin. Explain how this feature makes xylem adapted to transporting substances. 

Why does water move up a stem more quickly on a hot day than on a cool day?

Carlos has a celery stalk with leaves. He cuts the bottom off the stalk. Then he puts the stalk in a glass of water mixed with blue food colouring. The next morning, the celery leaves are blue. Carlos cuts the stalk halfway up and sees small blue circles within the stalk. 

Explain his observations.

Carlos has a celery stalk with leaves. He cuts the bottom off the stalk. Then he puts the stalk in a glass of water mixed with blue food colouring. The next morning, the celery leaves are blue. Carlos cuts the stalk halfway up and sees small blue circles within the stalk.

What are the blue circles inside the stalk?

Carlos has a celery stalk with leaves. He cuts the bottom off the stalk. Then he puts the stalk in a glass of water mixed with blue food colouring. The next morning, the celery leaves are blue. Carlos cuts the stalk halfway up and sees small blue circles within the stalk. 

Why have the leaves turned blue?

Carlos has a celery stalk with leaves. He cuts the bottom off the stalk. Then he puts the stalk in a glass of water mixed with blue food colouring.
The next morning, the celery leaves are blue. Carlos cuts the stalk halfway up and sees small blue circles within the stalk. 

Carlos's friend says that if you cut the leaves off a celery stalk, less water will be taken in by the stalk.

Plan an investigation method to find out if this might be true.