B5 Plant nutrition

Question 1

define photosynthesis

Answer 1

process of plants manufacturing carbohydrates from raw materials using energy from light

Question 2

state the word equation for photosynthesis

Answer 2

water + carbon dioxide –> glucose + oxygen

in the presence of light and chlorophyll

Question 3

state the balanced equation for photosynthesis

Answer 3

6CO2 + 6H2O –> C6H12O6 + 6O2

Question 4

explain the role of chlorophyll

Answer 4

it transfers light energy into chemical energy in molecules for carbohydrate synthesis

Question 5

state the uses of carbohydrate

Answer 5

• growth
• tissue repair
• make protein, enzymes and hormones
• produce cellulose

Question 6

carbohydrates can be stored as (2)

Answer 6

1. oil
2. starch

Question 7

describe how to investigate a leaf for starch

Answer 7

1. hold the leaf in boiling water to stop chemical reactions inside the leaf
2. boil it with ethanol to kill chlorophyll
3. rinse the leaf in cold water and add iodine solution

control - blue black as chlorophyll is present
no chlorophyll - yellow brown as no chlorophyll present

Question 8

describe the investigation to find out the necessity for chlorophyll using a variegated leaf

Answer 8

1. destach a variegated plant by placing it in complete dark for 48 hours
2. place it in sunlight so it can form starch
3. add iodine solution (following the procedures)

Question 9

describe the investigation to find out the necessity for light

Answer 9

1. destarch a plant
2. cut out 불투명 black paper and lip it in a section of a leaf
3. leave it in sunlight for few days
4. test it with iodine

Question 10

describe the investigation to find out the necessity for carbon dioxide

Answer 10

1. destarch 2 potted plants
2. cover both plants in transparent plastic bags, cover it with a flask containing limewater and sodium hydrocarbonate. sodium hydrocarbonate release CO2 and limewater will absorb it
3. leave it in sunlight for few days
4. iodine test

Question 11

what are the 3 factors that effects the rate of photosynthesis

Answer 11

1. light intensity
2. carbon dioxide concentration
3. temperature

Question 12

state the effect of temperature on the rate of photosynthesis

Answer 12

• as temperature increases, photosynthesis also increases
• temperature affects the enzymes
• the optimum environment provided

Question 13

how do you measure the effect of photosynthesis according to their light intensity

Question 14

importance of palaside mesophyll

Answer 14

photosynthesis

Question 15

importance of stomata, spongy mesophyll cells and guard cells

Answer 15

gas exchange

Question 16

importance of xylem

Answer 16

transport and support

Question 17

importance of phloem

Answer 17

transport

Question 18

importance of nitrate ions

Answer 18

makes amino acids, which is needed for cell growth

Question 19

importance of magnesium ions

Answer 19

makes chlorophylls, photosynthesis

Question 20

what happens when there is lack of nitrate ions

Answer 20

yellow, stunted, poor growth

Question 21

what happens when there is lack of magnesium ions

Answer 21

yellow