transport systems in plants 2.5

Question 1

what are the plants organs

Answer 1

roots, leaves, stems and flowers

Question 2

what structures in the leaf contain chloroplast

Answer 2

palisade mesophyll, spongy mesophyll and guard cells

Question 3

what is the waxy cuticle

Answer 3

the protective waterproof layer

Question 4

what is the upper epidermis

Answer 4

a protective and transparent single layer of cells which lets light pass through

Question 5

palisade mesophyll and spongy mesophyll

Answer 5

they contains chloroplast and is the site of photosynthesis

Question 6

the vein in plants

Answer 6

a branch of the main vein containing xylem and phloem

Question 7

what is the lower epidemis

Answer 7

a protective layer containing stomata and guard cells

Question 8

what are guard cells

Answer 8

controls the opening and closing of stomata

Question 9

stomata

Answer 9

pore which allows for gas exchange and exit of water

Question 10

describe the xylem

Answer 10

• the xylem transports water from the roots, through the stem to the leaves
• xylem vessels are dead and are composed of non-living hollow tubes
• xylem vessels are composed of rings of lignin, which give the plant support

Question 11

describe the phloem

Answer 11

• phloem vessels are responsible for transporting sugar from the leaves in all directions
• phloem cells are living and at the end of each cell there is a sieve plate to help pass sugar down a sieve tube
• phloem vessels also have companion cells attached which provide energy

Question 12

what is transpiration

Answer 12

the process in which water leaves the leaf by evaporating through the stomata

Question 13

when is the stomata open and closed

Answer 13

during daylight hours the stomata are open and during the night in darkness stomata are closed

Question 14

transport of water through a plant

Answer 14

1. water enters the root hairs cells by osmosis and moves from cell to cell along the concentration gradient before entering the non-living xylem
2. water travels up the xylem and into the leaf
3. water travels through the leaf cell by osmosis
4. water vapour is lost by transpiration through the stomata

Question 15

factors that affect transpiration

Answer 15

humidity, surface area, wind speed and temperature

Question 16

what happens to transpiration when the wind speed, surface area and temperature increases

Answer 16

rate of transpiration increases

Question 17

what happens to transpiration when the humidity increases

Answer 17

rate of transpiration decreases