Leaves

Question 1

Where are leaves attached to stems?

Answer 1

At nodes

Question 2

What is the stalk of the leaf called?

Answer 2

the petiole

Question 3

How do some leaves not have a petiole?

Answer 3

They are joined directly to the stem

Question 4

What are leaves without petioles said to be?

Answer 4

They are said to be sessile

Question 5

Explain how the petiole effects the growth of a leaf

Answer 5

The leaf is normally flattened into a thin leaf blade or lamina.
The petiole continues through the lamina as the midrib.
Veins emerge from the midrib and are clearly seen in the lamina.
The petiole, midrib and veins contain vascular or transport tissues called xylem and phloem.

Question 6

What emerges from the midrib when the petiole continues through the lamina as the midrib?

Answer 6

Veins emerge from the midrib and are clearly seen in the lamina.

Question 7

What do the petiole, midrib and veins contain in a plant?

Answer 7

The petiole, midrib and veins contain vascular or transport tissues called xylem and phloem.

Question 8

Define venation

Answer 8

Venation is the pattern of veins in a leaf

Question 9

Give the two most common types of venation

Answer 9

1. Parallel venation

2. Net or reticulate venation

Question 10

Explain parallel venation. Give examples of this

Answer 10

Parallel venation means that the veins run alongside each other.
This pattern is found in most monocots, e.g. grasses, daffodils and tulips

Question 11

Explain net or reticulate venation

Answer 11

Net or reticulate venation means that the veins form a branching network throughout the lamina.
This pattern is most common in dicots, e.g. horse chestnut, rose and buttercup

Question 12

Where is net or reticulate venation most commonly found?

Answer 12

This pattern is most common in dicots, e.g. horse chestnut, rose and buttercup

Question 13

Where is parallel venation most commonly found?

Answer 13

This pattern is found in most monocots, e.g. grasses, daffodils and tulips

Question 14

Give all 4 functions of leaves

Answer 14

1. Make food (carry out photosynthesis).
2. Exchange gases with the atmosphere (in daylight they take in carbon dioxide and release oxygen and water vapour)
3. Lose water (in a process called transpiration) - this allows fresh water and mineral salts to be taken into the plant and it may also cool the plant.
4. Store food.

Question 15

How does the function to lose water benefit a plant?

Answer 15

This allows fresh water and mineral salts to be taken into the plant and it may also cool the plant.

Question 16

What is the process of losing water in a plant called?

Answer 16

Transpiration