Chapter 6: Plant Nutrition

Question 1

What is photosynthesis?

Answer 1

the process by which plants synthesise carbohydrates from raw materials using energy from light

Question 2

Balanced word equations for photosynthesis

Answer 2

6CO2 + 6H2O → C6H12O6 + 6O2

in the presence of light and chlorophyll

Question 3

What is chlorophyll?

Answer 3

is a green pigment that is found in chloroplasts

Question 4

What is chlorophyll?

Answer 4

transfers energy from light into energy in chemicals, for the synthesis of carbohydrates

Question 5

use and storage of the carbohydrates made in photosynthesis

Answer 5

(a) starch as an energy store
(b) cellulose to build cell walls
(c) glucose used in respiration to provide energy
(d) sucrose for transport in the phloem
(e) nectar to attract insects for pollination

Question 6

Importance of nitrate ions

Answer 6

For making amino acids

Question 7

Importance of magnesium ions

Answer 7

For making chlorophyll

Question 8

Investigate need for chlorophyll

Answer 8

Take a potted plant with variegated leaves, keep it in complete darkness for 48 hours to destarch it. Place it in sunlight to allow new starch formation. Perform a starch test using iodine. Green parts turn blue-black (indicating starch presence with chlorophyll), while white parts turn orange-brown, demonstrating that photosynthesis only occurs where chlorophyll is present.

IV=chlorophyll
DV=starch

Question 9

Investigation for CO2

Answer 9

Destarch two potted plants by covering them with transparent plastic bags. Place a petri dish of sodium hydrogencarbonate in one and soda lime in the other. Sodium hydrogencarbonate releases carbon dioxide, while soda lime absorbs it. Leave both plants in sunlight for at least 6 hours. Perform a starch test on a leaf from each plant. The leaf from the plant with sodium hydrogencarbonate turns blue-black, indicating starch (presence of carbon dioxide), while the leaf from the plant with soda lime turns orange-brown, illustrating the necessity of carbon dioxide for photosynthesis.

IV= CO2
DV= rate of photosynthesis

Question 10

Investigate for light

Answer 10

To destarch a plant, clip a strip of opaque black paper onto a leaf section. Leave the plant in sunlight for a few days. Perform a starch test - areas exposed to sunlight turn blue-black (indicating starch presence), while the covered section remains orange-brown. This demonstrates that light is necessary for photosynthesis.

IV=light
DV=stratch

Question 11

hydrogen carbonate indicator

Answer 11

an increase in carbon dioxide changes the indicator to yellow and a decrease in carbon dioxide changes it to purple.

Question 12

Leaf properties

Answer 12

Large surface area and thin

-Leaves have a large surface area so that they can maximize light absorption.
- They are thin and flat so that carbon dioxide has a shorter distance to diffuse and the diffusion therefore occurs at a faster rate.

Question 13

Structure of leaf

Answer 13

https://o.quizlet.com/7tqYNzTYOoXJ51Ucwbp.Qg_b.jpg

Question 14

Functions of cuticle

Answer 14

Made of wax, secreted by upper epidermis.
Helps in water proofing the leaf to prevent water loss.

Question 15

Upper epidermis

Answer 15

This and transparent, absence of chloroplasts.
Act as a protective layer & barrier to disease organism allows sunlight to penetrate.

Question 16

Palisade mesophyll

Answer 16

No gaps between cells. Cells are long, packed with chloroplasts.
Main region for absorption of light for photosynthesis

Question 17

Spongy mesophyll

Answer 17

Spherical, loosely packed, contain chloroplasts but not as many as palisade.
Air spaces between cells allow gaseous exchange - carbon dioxide to the cells, oxygen from the cells during photosynthesis.

Question 18

Vascular bundle

Answer 18

Thin vein made of xylem and phloem
Xylem vessels bring water and minerals to the leaf, phloem vessels transport sugars and amino acids away from the leaf.

Question 19

Lower epidermis

Answer 19

Stomata present
Acts as a protective layer

Question 20

Stomata

Answer 20

Surrounded by guard cells.
Guard cells regulate whether the stomata is open or closed to allow carbon dioxide in and regulate the loss of water vapour during transpiration.