plant sensitivity and transport

Question 1

what is excretion

Answer 1

Excretion is the removal ofwaste products from metabolicreactions

Question 2

what is the photosynthesis equation

Answer 2

6CO2 + 6H2O ==> C6H12O6 + 6O2

Question 3

what is the respiration equation

Answer 3

C6H12O6 + 6O2 ==> 6CO2 + 6H2O

Question 4

how do the leaves being thin effect gas exchange

Answer 4

So internal diffusion distance is small

Question 5

how does the irregular shapes of spongy mesophyll effect gas exchange

Answer 5

enhances gas exchange with the gaps between the spongy mesophyll

Question 6

how do palisade cells being close to air spaces effect gas exchange

Answer 6

the distance for the site at which photosynthesis is taking place is small

Question 7

how does moisture on the inside of the leaf effect gas exchange

Answer 7

Gases can dissolve in the moisture and then diffuse into cells

Question 8

how does the amount of water moving about by osmosis effect the cell

Answer 8

As water moves in by osmosis, the cells become more turgid and as water moves out by osmosis, the cells become more flaccid

Question 9

why does the guard cell curve when water enters the cell

Answer 9

Because of a thickened wall on one side, when water enters the cell by osmosis, the guard cell curves

Question 10

what happens when photosynthesis and respiration proceed at the same rate

Answer 10

there is no net gain or loss of carbohydrate. The plant is at its compensation point

Question 11

what are the adaptations of xylem vessels

Answer 11

walls are thickened with lignin(waterproof, strong and prevents cells from collapsing inwards), the cells are dead(no obstruction to the flow of water for there are no organelles or cytoplasm) and the end walls were removed so cells join to form long tubes called xylem vessels

Question 12

what is the movement of the substance in the phloem called

Answer 12

Translocation

Question 13

what are the adaptations of the phloem vessels

Answer 13

sieve tubes(transports sugars around the plant), thin cytoplasm(active transport can take place), Pores in sieve plates(allows sugars to pass from one cell to the next), no nucleus or organelles(the sugar flow can not be impeded) and a companion cell(carries out some of the life processes for the sieve tube but doesn’t transport sugar)

Question 14

to what stimuli do plants respond

Answer 14

gravity, light and water

Question 15

what is tropism

Answer 15

Growth movement of a plant in response to a directional stimulus and is caused by plant hormones

Question 16

what does the plant hormone auxin effect

Answer 16

Auxin affects the speed of growth of the cells in which it accumulates

Question 17

what is phototropism

Answer 17

The growth response of a plant to light is called phototropism
Shoots show positive phototropism (grow towards the light)
Roots show negative phototropism (grow away from the light)

Question 18

what is geotropism

Answer 18

The growth response of a plant to gravity is called geotropism
Shoots show negative geotropism
Roots show positive geotropism

Question 19

how do plants regulate their growth

Answer 19

auxin are produced in the shoots then get transported down from the tip to the region of cell expansion all the cells then elongate at the same time so the plant grows straight up

Question 20

Why do plants grow in different directions sometimes then

Answer 20

the auxin can go to a certain side based on factors such as geotropism and phototropism to make it grow in a certain direction

Question 21

describe the flow of water throughout a plant

Answer 21

1. Water enters through root hair cells by osmosis
2. Water containing dissolved minerals is carried up by the root and stem xylem vessels
3. Water evaporates from the leaves

Question 22

what are factors effecting the rate of transpiration

Answer 22

1. temperature
2. humidity
3. wind speed
4. light intensity
5. water supply