plant nutrition 🎀

Question 1

what does photosynthesis produce for a plant?

Answer 1

‘food’ so it can survive

Question 2

what energy does photosynthesis convert?

Answer 2

light energy to chemical energy

Question 3

word equation for photosynthesis?

Answer 3

carbon dioxide + water - glucose + oxygen

Question 4

balanced chemical equation for photosynthesis?

Answer 4

6CO2 + 6H2O - C6H12O6 + 6O2

Question 5

TESTING A LEAF FOR STARCH: why do you boil the leaf for 2 mins in water?

Answer 5

kills the leaf and stops it photosynthesising

Question 6

TESTING A LEAF FOR STARCH: why do you turn the bunsen burner off?

Answer 6

ethanol is flammable

Question 7

TESTING A LEAF FOR STARCH: why do you heat the leaf in ethanol?

Answer 7

removes the green colour (chlorophyll) from leaf

Question 8

TESTING A LEAF FOR STARCH: why do you rinse the leaf in warm water?

Answer 8

softens leaf

Question 9

TESTING A LEAF FOR STARCH: why do you add iodine to the leaf?

Answer 9

see if leaf contains starch

Question 10

why is light needed for photosynthesis?

Answer 10

• cover part of leaf with aluminium foil and leave in sunlight.
• covered parts will be negative for starch (orange/brown)
• uncovered parts will be positive for starch (blue/black)

Question 11

why is chlorophyll needed for photosynthesis?

Answer 11

• variegated leaves show this.
• white parts go orange/brown when tested with iodine
• green parts (containing chlorophyll) turn blue/black

Question 12

why is carbon dioxide needed for photosynthesis?

Answer 12

• place plant in beaker of sodium hydroxide (which will absorb CO2 from air)
• place another plant in beaker of water (which will not absorb CO2 from air)

Question 13

what does the magnesium ion do?

Answer 13

make chlorophyll

Question 14

what happens to the plant without magnesium ions?

Answer 14

yellow leaves due to less chlorophyll being produced

Question 15

what does the nitrate ion do?

Answer 15

combine with glucose to make amino acids (proteins) for growth.

Question 16

what happens to the plant without nitrate ions?

Answer 16

stunted/less growth due to less protein produced.

Question 17

as light intensity increases…

Answer 17

the rate of respiration INCREASES up to a MAXIMUM where it LEVELS OFF.

(even at high light intensity, another factor limits the rate).

Question 18

as co2 concentration increases…

Answer 18

the rate of respiration INCREASES up to a MAXIMUM where it LEVELS OFF.

(even at high co2 concentration, another factor limits the rate).

Question 19

as temperature increases…

Answer 19

the rate of respiration INCREASES up to a MAXIMUM where it DECREASES.

(at high temperatures the enzymes denature).

Question 20

STRUCTURE OF LEAF -
how is the waxy cuticle adapted for photosynthesis

Answer 20

waterproof layer - prevents water loss

Question 21

LEARN HOW TO LABEL DIAGRAM FOR LEAF PARTS

Answer 21

A* GIRLIEEE

Question 22

STRUCTURE OF LEAF -
how is the upper epidermis adapted for photosynthesis

Answer 22

transparent - maximises sunlight passing through

Question 23

STRUCTURE OF LEAF -
how is the palisade mesophyll adapted for photosynthesis

Answer 23

lots of chloroplasts near top of leaf - long and thin to increase S.A. for max light absorption.

Question 24

STRUCTURE OF LEAF -
how is the spongy mesophyll adapted for photosynthesis

Answer 24

air spaces - increase S.A. for movement of gases in and out of leaf. close to stomata.

Question 25

STRUCTURE OF LEAF - how is the xylem adapted for photosynthesis

Answer 25

supplies water to leaf from roots

Question 26

STRUCTURE OF LEAF - how is the lower epidermis/guard cells adapted for photosynthesis

Answer 26

many stomata allow CO2 to move in and O2 and water vapour out by diffusiom.

Question 27

EVOLUTION OF O2 FROM ELODEA what was dependent variable?

Answer 27

count the number of O2 bubbles produced per minute to measure rate of photosynthesis.

Question 28

EVOLUTION OF O2 FROM ELODEA what was independent variable?

Answer 28

change distance of light from plant to change light intensity.

Question 29

EVOLUTION OF O2 FROM ELODEA what was control variable?

Answer 29

amount of CO2 or temperature.