Leaves

Question 1

Why to leaves have a large surface area?

Answer 1

To absorb light rays

Question 2

Why do they have a thin shape?

Answer 2

So gases can diffuse in and out quickly.

Question 3

Why do they have green chlorophyll?

Answer 3

To absorb light

Question 4

Why do leaves have veins?

Answer 4

To support the leaf surface and to carry substances to and from all the cells in the leaf.

Question 5

What is the cuticle?

Answer 5

Waterproof layer that also cuts down the water lost by evaporation.

Question 6

What is the upper epidermis?

Answer 6

Single layer of cells with no chloroplasts. Light goes straight through.

Question 7

What is the palisade layer?

Answer 7

The palisade cell contains lots of chloroplasts. Most photosynthesis occurs here.

Question 8

What is the vein?

Answer 8

Contains tubes called xylem that bring water and salts to the leaf and tubes called phloem that take dissolved food away.

Question 9

What is the spongy layer?

Answer 9

More rounded cells with lots of air spaces between them, gaseous exchange occurs here.

Question 10

What is the lower epidermis?

Answer 10

No thick cuticle. Has lots of tiny pores called stomata (singular stoma) . These allow gases to diffuse in and out.

Question 11

What are stomata?

Answer 11

Small pores on the underside of the leaf that let gases diffuse in and out.

Question 12

________ diffuse in for photosynthesis. _____ made in photosynthesis diffuses out. Water _____ diffuses out.

Answer 12

Carbon dioxide
Oxygen
Vapor

Question 13

Why are stomata in the underside of the leaf?

Answer 13

Stomata are present on the lower epidermis to reduce the loss of water by evaporation as less sunlight falls on the lower epidermis.

Question 14

How can stomata be opened and closed?

Answer 14

By guard cells

Question 15

When do stomata usually open?

Answer 15

During the day

Question 16

How does water pass into the guard cells?

Answer 16

Osmosis. This makes them bend so the stoma opens. Carbon dioxide diffuses into the leaf for photosynthesis.

Question 17

The stomata close at _____. Water passes out of the cells by _______. They ______ up so the so the stoma closes.

Answer 17

Night
Osmosis
Straighten

Question 18

Why do stomata close during hot weather ?

Answer 18

In many plants, when the outside temperature is warm and water evaporates more readily, plants close their stomata to prevent excessive water loss.

Question 19

What do plants need to do for respiration?

Answer 19

Take in oxygen and give out carbon dioxide. Respiration takes place all the time.

Question 20

What to plants need to happen for photosynthesis which is opposite to respiration?

Answer 20

Take in carbon dioxide and give out oxygen. Photosynthesis only takes place in the light.

Question 21

The gases pass into and out of leaves through the _____.

Answer 21

Stomata

Question 22

Why do we have plant food on sale?

Answer 22

Plants need mineral salts or nutrients.

Question 23

Why do plants need nitrates?

Answer 23

Need the nitrogen to make proteins. So nitrogen is one nutrient needed for growth.

Question 24

What is magnesium used for in plants?

Answer 24

To make chlorophyll. Leaves without magnesium look yellow. We say the plant is deficient in magnesium.

Question 25

During daylight plants produce more oxygen by ____ than they use in _______. At night plants produce only _______ by respiration.

Answer 25

Photosynthesis
Respiration
Carbon dioxide

Question 26

How can you tell a plant lacks nitrate?

Answer 26

Stunted growth and yellow older leaves

Question 27

How can you tell a plant lacks phosphate?

Answer 27

Poor root growth and purple younger leaves.

Question 28

How can you tell a plant lacks potassium?

Answer 28

Yellow leaves with dead spots.

Question 29

Adaption of epidermis:

Answer 29

Epidermal cells are transparent with no chloroplasts so light goes through

Question 30

Why does the leaf have vascular bundles?

Answer 30

For water (xylem) and food (phloem)

Question 31

What is stomata used for?

Answer 31

Gas exchange

Question 32

Adaptation of palisade mesophyll:

Answer 32

Many chloroplasts for photosynthesis

Question 33

Adaptation of spongy mesophyll:

Answer 33

More rounded with lots of air spaces to make gas exchange easier.

Question 34

What are parenchyma cells?

Answer 34

Thin-walled cells that make up the inside of many non-woody plant structures including stems, roots and leaves.

Question 35

What is the function of parenchyma?(3)

Answer 35

Healing & Repair
Photosynthesis
Nutrient and food storage

Question 36

What is collenchyma?

Answer 36

Tissue strengthened by the thickening of cell walls.

Question 37

What is the function of collenchyma?

Answer 37

Enable additional support to the areas they are found.