Plant structures and Functions

Question 1

what does chlorophyll do?

Answer 1

absorbs light

Question 2

equation for photosynthesis

Answer 2

carbon dioxide + water - glucose + oxygen

Question 3

what kind of reaction is photosynthesis?

Answer 3

endothermic reaction

Question 4

what effects the rate of photosynthesis?

Answer 4

light intensity
concentration of CO2
temperature

Question 5

what is a limiting factor?

Answer 5

something that stops the reaction happening any faster

Question 6

Light intensity relationship

Answer 6

the rate of reaction is directly proportional to light intensity up to a certain point

Question 7

why does the light graph plateau?

Answer 7

Because temperature or volume of CO2 needs to be increased as is the limiting factor

Question 8

relationship between distance of lamp and light intensity

Answer 8

they are inversely proportional so when the distance increases the light intensity decreases

Question 9

Temperature for photosynthesis

Answer 9

enzymes needed for photosynthesis work slower at low temps

if it gets too hot the enzymes denature at around 45 degrees

Question 10

Root hair cell function

Answer 10

takes in minerals and water through active transport and osmosis

Question 11

Root hair cell structure

Answer 11

covered in millions of micro hairs

large surface area to absorb

Question 12

What are phloem tubes?

Answer 12

made up of columns of elongated living cells with small pores in the end walls to allow stuff to flow through

Question 13

what do phloem tubes do?

Answer 13

transport food substances for immediate use or storage

Question 14

what is translocations?

Answer 14

transport of food using energy from respiration in both directions

Question 15

what are xylem tubes?

Answer 15

made up of dead cells joined end to end with no end walls between them and a hole down the middle.

Question 16

what strengthens xylem tubes?

Answer 16

lignin

Question 17

what do xylem tubes do?

Answer 17

carry water and mineral ions from roots to stem and leaves

Question 18

what is a transpiration stream?

Answer 18

movement of water from roots through xylem and out of the leaves

Question 19

what causes transpiration?

Answer 19

evaporation and diffusion of water from a plants surface

Question 20

what is transpiration?

Answer 20

loss of water from the plant

Question 21

what does transpiration cause?

Answer 21

a slight shortage of water in the lead

Question 22

How to deal with the shortage of water

Answer 22

more water is drawn up from plant through xylem vessels and causes a constant transpiration stream

Question 23

what are stomata?

Answer 23

tiny pores on the surface of a plant

Question 24

what do stomata cells do?

Answer 24

allow gas exchange through diffusion in and out of the leaf.

Question 25

What escapes through the stomata?

Answer 25

water vapour

Question 26

why does the water escape?

Answer 26

because there’s more water inside the plant than outside so it diffuses out the leaves

Question 27

what happens when guard cells are turgid?

Answer 27

the stomata is open

Question 28

what happens when guard cells are flaccid?

Answer 28

the stomata is closed

Question 29

what do guard cells do?

Answer 29

change shape to control the size of the pore

Question 30

Light intensity affect on transpiration

Answer 30

the brighter the light the greater the transpiration rate

Question 31

Temperature affect on transpiration

Answer 31

the warmer it is the faster the transpiration happens

Question 32

why does this happen due to temperature?

Answer 32

particles have more energy to evaporate and diffuse out

Question 33

air flow affect on transpiration

Answer 33

the better the air flow the greater the transpiration rate

Question 34

what happens if the air flow is poor around the leaf?

Answer 34

water vapour just surrounds the leaf and doesn’t move away because there is a high concentration inside as well as outside so diffusion doesn’t happen as quick

Question 35

what happens if there is good air flow around the leaf?

Answer 35

water vapour is swept away maintaining a low concentration of water in the air outside the leaf and diffusion happens quickly

Question 36

how to estimate transpiration rate?

Answer 36

use a potometer which measures water uptake

start stopwatch and record distance moves by bubble per unit time

Question 37

what is the problem with a potometer?

Answer 37

is assumes that water uptake by the plant is directly related to water loss from the leaves