Plant functions

Question 1

-what are specialised plant cells?

Answer 1

phloem and xylem

Question 2

what are some specialised features of the phloem cell and what are its uses

Answer 2

-contains sieve tube elements which have very little cytoplasm so that there is a lot of space for the transportation of sucrose
- contains companion cells that contain the nucleus.
- has lots of mitochondria for active transport

Question 3

what are some specialised features of the xylem? cells

Answer 3

• they are dead cells so have no cell contents for water and ions to move
• that have holes in their wall called pits that let water and minerals move in and out of them
• they have strengthened walls to prevent them from collapsing
• they have no ends so they are tube

Question 4

what is transpiration

Answer 4

the system that moves water from the roots to the leaves

Question 5

what are the 4 steps for transpiration

Answer 5

1. water enters the roots via osmosis
2. draws water up through the xylem
3. water goes out of the xylem into leaf cells
4. water evaporates from the stomata of leaves

Question 6

what are stomata

Answer 6

cells that are found on the lower surface of the leaf, the open water is absorbed and closed when shut when there is no water

Question 7

what is translocation

Answer 7

the transport of sucrose around a plant

Question 8

what happens during translocation

Answer 8

sucrose is transported around the plant through the phloem

Question 9

explain the waxy cuticle (location, use, adaptations )

Answer 9

is the outermost layer of the leaf, is transparent to let light through, protects the leaf

Question 10

explain the mesophyll cells (location, use, adaptations )

Answer 10

underneath the cuticle, large surface area, full of chloroplasts for photosynthesis

Question 11

why does air surround most of the surface of plant cells

Answer 11

so that gas exchange can occur over a larger surface

Question 12

what is between the mesophyll cells and the waxy cuticle

Answer 12

epidermis cells

Question 13

why are stomata open

Answer 13

to let carbon dioxide into the leaf and to let oxygen out

Question 14

what are 3 factors that affect the rate of transpiration

Answer 14

light intensity
air movement
temperature

Question 15

how does light intensity affect the rate of transpiration

Answer 15

increases transpiration as it will cause more evaporation to happen and for more water to be transported up

Question 16

how does air movement affect the rate of transpiration

Answer 16

wind blows moist air away from the stomata keeping diffusion gradients high so that more transportation occurs

Question 17

how does temperature affect the rate of transpiration

Answer 17

the higher the temperature. the more energy the water molecules have which means faster the rate of transpiration

Question 18

what are some plant adaptions and their reasons for plants in dry areas

Answer 18

stomata sunk into pits - reduce water loss
waxy cuticle - reduces water loss
rolled leaf - reduce movement of air around stomata
leaf hairs - to trap moist air around stomata

Question 19

what are some plant adaptions and their reasons for plants in tropical conditions

Answer 19

large leaves - to collect as much sunlight as possible
stems and leaves that climb trees - to reach sunlight
drip tips - so that water runs off them

Question 20

what are some plant adaptions and their reasons for plants in waterlogged areas

Answer 20

spongy tissue in roots - stores oxygen
fine surface roots - take in oxygen at the water surface

Question 21

what are some plant adaptions of cactus plants

Answer 21

no leaves - reduces water loss
green body for photosynthesis
large root system to collect water