The Leaf

Question 1

What is the palisade mesophyll?

Answer 1

Top layer of mesophyll

Contains chloroplasts

Long narrow and close together

Question 2

What is transpiration?

Answer 2

Evaporation of water from plant leaves

Question 3

What is the cell wall of a phloem and xylem made from?

Answer 3

Xylem is lignin

Phloem is cellulose

Question 4

What is the upper epidermis ?

Answer 4

Covers the leaf and absorbs light

Question 5

What is the spongy mesophyll?

Answer 5

Allows co2 and water to enter cells for photosynthesis

Question 6

What is xylem and phloem made from?

Answer 6

Xylem is dead cells

Phloem is living cells

Question 7

What is the waxy cuticle?

Answer 7

Waterproof layer to reduce water loss and redirect rainwater into soil so roots can absorb

Question 8

What are guard cells?

Answer 8

Cells that open and close the stomata depending on water content

Question 9

What is the stomata?

Answer 9

Pores that allows co2 to absorb into the leaf

Question 10

What is the lower epidermis?

Answer 10

Bottom layer of leaf with many pores which allows co2 to disuse into leaf

Question 11

What is translocation?

Answer 11

The movement of sugars through a plant in phloem

Question 12

Why are there spaces between spongy mesophyll?

Answer 12

To allow diffusion of c02 and water to evaporate

Question 13

Explain how the palisade tissue layer is adapted to carry out photosynthesis.

Answer 13

It has many chloroplasts to absorb more sunlight or photosynthesis

Question 14

What are the steps for photosynthesis?

Answer 14

Chlorophyll absorbs sunlight in chloroplast

Water enters plant in root by osmosis and travels to leaves in xylem vessels

Co2 diffuses into leaf through stomata.

Guard cells control stoma size depending on light intensity

Photosynthesis takes place

Light energy converts water and co2 into glucose and oxygen

Question 15

How is glucose used?

Answer 15

For respiration

To produce fat and storage

To produce amino acids

Question 16

Describe the transport of water though a plant from the roots to the atmosphere

Answer 16

Water moves through translocation

In xylem cells

Water moves into mesophyll cells

Evaporate

Leave plant via stoma

Question 17

Explain how and why stomata open in the day and close at night.

Answer 17

In the day, it is light and the guard cells gain water so become turgid, opening the stomata.

This allows carbon dioxide to enter the cell for photosynthesis and oxygen diffuses out.

At night, it is dark, so plants cannot photosynthesise.

The guard cells lose water and become flaccid, closing the stomata.

This prevents excess water loss.

Question 18

Give 3 differences between xylem and phloem vessels.

Answer 18

Xylem transports water and mineral ions whereas the phloem transports food substances.

Xylem only transports molecules up the plant (one way) but phloem vessels transport molecules all around the plant (moves both ways).

Xylem cells are dead, phloem cells are living.

Xylem cells have no cell walls at the top and bottom to allow substances to pass through

phloem cells have sieve plates between cells to allow substances to pass through.

Question 19

Give factors that affect the rate of transpiration

Answer 19

Temperature

Wind speed

Humidity

Light intensity

Question 20

What is the purpose of translocation in plants

Answer 20

Movement of materials from leaves to other areas of the plant

Question 21

What is the role of stomata and guard cells?

Answer 21

Control gas and water loss

Question 22

What is the role of meristems?

Answer 22

Trigger growth of new cells

Question 23

Where are meristems found?

Answer 23

Growing tips

Roots or shoots

Question 24

Explain how the spongy mesophyll is adapted for its function

Answer 24

Large air spaces to increase surface so carbon dioxide can diffuse into leaf