3.1 leaf structure

Question 1

epidermis

Answer 1

tough, transparent layer of cells surrounding mesophyll tissue. protects the organs (of the leaf) from mechanical damage

Question 2

petiole (leaf stalk)

Answer 2

holds leaf in position to absorb maximum light energy

Question 3

lamina (leaf blade)

Answer 3

its broadness provide large surface area for maximum absorption of light.
its thinness provides short diffusion distance for gases and enables light to reach all mesophyll cells

Question 4

cuticle

Answer 4

impervious and waxy, which reduces water loss through evaporation. transparent for light to reach cells

Question 5

stomata

Answer 5

sites of gaseous exchange. opens in the presence of light, allowing carbon dioxide to diffuse in and oxygen to diffuse out of the leaf

Question 6

chloroplasts in chlorophyll cells

Answer 6

contains chlorophyll that is required for photosynthesis to take place. chlorophyll absorbs and transforms light energy to chemical energy used in the manufacture of sugar

Question 7

chloroplasts in upper palisade mesophyll tissue

Answer 7

vertically arranged cells packed with chloroplasts, and compacted along upper epidermis, more light energy can hence be absorbed near the leaf surface

Question 8

air spaces in spongy mesophyll

Answer 8

allows for rapid diffusion of carbon dioxide and oxygen in and out of the cell. has loosely arranged cells to allow for diffusion of co2

Question 9

leaf veins situated close to mesophyll cells

Answer 9

xylem transports water and mineral salts to mesophyll cells

phloem transports sugar away from the leaf

Question 10

vascular bundles

Answer 10

transport water and products of photosynthesis, as well as provides mechanical support to leaves