section 3 - plant nutrition and transport

Question 1

what do chloroplasts contain

Answer 1

chlorophyll which absorbs sunlight

Question 2

what is the equation for photosynthesis

Answer 2

carbon dioxide + water -> glucose + oxygen

Question 3

why is photosynthesis important

Answer 3

converts light energy to chemical energy, which is stored in glucose. released when glucose is broken down during respiration

Question 4

how are leaves adapted for efficient photosynthesis

Answer 4

1. broad so large SA exposed to light
2. chloroplasts found in palisade layer near the top
3. the upper epidermis is transparent so light can pass to the palisade layer
4. contain xylem and phloem for water and nutrients and support the leaf structure
5. waxy cuticle reduces water loss by evaporation
6. stomata for diffusion of gasses and efficient photosynthesise

Question 5

what are 3 limiting factors

Answer 5

lights, CO2, temperature

Question 6

what is a limiting factor

Answer 6

stops photosynthesis from happening any faster

Question 7

why do you dunk the leaf in boiling water in the test for starch

Answer 7

stops any chemical reactions

Question 8

why do you put the leaf in ethanol

Answer 8

gets rid of chlorophyll into a white-ish colour

Question 9

test to show chlorophyll is needed for photosynthesis

Answer 9

1. take a variegated leaf
2. test the leaf for starch using boiling waeter ethanol and iodine soltution
3. only bits that were green turn blue black

Question 10

how to test that co2 is needed for photosynthesis

Answer 10

using a sealed bell jar, light, plant and soda lime to absorbs co2 out of the air. if leave the plant in the jar and then test for starch it won’t turn blue black, suggesting that it hasn’t photosynthesised,

Question 11

oxygen production shows the rate of photosynthesis

Answer 11

use light source and vary distance from the plant, use gas syringe and Canadian pondweed in water and sodium hydrogencarbonate for enough co2

Question 12

what are nitrates used for in plants

Answer 12

making proteins and amino acids for cell growth - could be stunted and leaves turn yellow

Question 13

what are phosphates used for

Answer 13

making DNA and cell membranes and respiration and growth. - poor root growth and leaves turn purple

Question 14

what is magnesium used for

Answer 14

makes chlorophyll - have yellow leaves

Question 15

what are xylem for

Answer 15

transport water and mineral salts from the shoots to the leaves in tranpspiration stream

Question 16

what are phloem for

Answer 16

transports sugars like sucrose and amino acids by translocation

Question 17

adaptations of root hair cells

Answer 17

1. large SA to increase rate of absorption
2. lots of mitochondria for respiration to provide energy for active transport
3. have thin walls for short diffusion distance

Question 18

what is transpiration caused by

Answer 18

evaporation and diffusion - when water shortage more water is drawn up from the rest of the plant

Question 19

what 4 things affect the transpiration rate

Answer 19

light intensity, temperature, wind speed, humidity

Question 20

how does light intensity affect transpiration

Answer 20

more photosynthesis and stomata is open and water escapes

Question 21

how does temperature affect tranpirtation

Answer 21

particles have ore energy to evaporate and diffuse out of the stomata

Question 22

how does wind speed affect transpiration

Answer 22

if it is windy, water vapor is swept away, maintaining a slow concentration of water in the air outside the lead causing diffusion to happen quickly

Question 23

how does humidity affect tranpirstion

Answer 23

the drier the air the faster transpiration happens, if the air is humid there is lots of water in it already so not much concentration difference inside out outside the leaf

Question 24

what apparatus is used to estimate transpiration rate

Answer 24

potometer