Leaf Structure

Question 1

Which leaf tissue carries out the most photosynthesis?

Accepted Answer

Palisade mesophyll — Palisade mesophyll cells are packed with chloroplasts and do most photosynthesis.

Question 2

The air spaces needed for gaseous diffusion inside a leaf are found in the

Accepted Answer

spongy mesophyll — Spongy mesophyll has loosely packed cells with air spaces for gas diffusion.

Question 3

A stoma is opened and closed by a pair of

Accepted Answer

guard cells — Two guard cells border each stoma and control its opening and closing.

Question 4

Which structure reduces water loss from the leaf surface?

Accepted Answer

Waxy cuticle — The waxy cuticle is waterproof and limits evaporation from the surface.

Question 5

In most leaves the greatest number of stomata is found on the

Accepted Answer

lower epidermis — Most stomata are on the cooler, shaded lower epidermis to reduce water loss.

Question 6

Which tissue in the leaf vein carries water and mineral salts?

Accepted Answer

Xylem — Xylem in the veins delivers water and mineral salts to leaf cells.

Question 7

Guard cells differ from other epidermal cells because they

Accepted Answer

contain chloroplasts — Guard cells are the only epidermal cells that contain chloroplasts.

Question 8

A leaf is broad and thin. The main advantage of being thin is that

Accepted Answer

gases and light reach inner cells easily — Thinness gives short diffusion distances so light and gases reach inner cells.

Question 9

The upper epidermis of a leaf has no chloroplasts, which allows it to

Accepted Answer

let light pass to the palisade layer — Without chloroplasts the upper epidermis is transparent, letting light reach palisade cells.

Question 10

The sugar made during photosynthesis is carried away from the leaf by the

Accepted Answer

phloem — Phloem translocates the sugar produced in the leaf to the rest of the plant.