Ch.20 Photosynthesis Flashcards
What is photosynthesis?
Photosynthesis is the process by which organic food (carbohydrates) are made from simple inorganic substances (carbon dioxide and water) using light energy.
[LQ]
What is released as a by-product of photosynthesis?
Oxygen.
[LQ]
What is the word equation for the overall process of photosynthesis?
carbon dioxide + water ↓ ↓ light energy ↓ chlorophyll ↓ carbohydrates + oxygen
[Blanks filling]
Significance of photosynthesis:
- Provide the basic ______ source for most organisms.
- Maintains ______ ______ in ecosystems.
- Maintains the balance of ______ and ______ _________ in the atmosphere.
- Provides the basic {food} source for most organisms.
- Maintains {energy flow} in ecosystems.
- Maintains the balance of {oxygen} and {carbon dioxide} in the atmosphere.
[Matching]
Methods to determine if a leaf has carried out photosynthesis:
1. detect the production of oxygen from the leaf
2. detect the presence of starch in the leaf
(__) using a glowing splint.
(__) by iodine test.
(1) using a glowing splint.
(2) by iodine test.
[Blanks filling]
If we plan to use the presence of starch in leaves as evidence that photosynthesis has occurred, any starch that is present in the leaves before the investigation must be removed by ___________.
destarching (脫澱粉)
[LQ]
What is the definition and purposes of destarching?
Destarching is the removal of starch from the leaves of a plant by putting it in the dark for at least 24 hours.
This is to make sure that the starch detected at the end of the investigation was made during the investigation..
[MC]
Which of the following are required for photosynthesis?
1) light 2) carbon dioxide 3) water 4) starch
A. 2 and 3
B. 1, 2 and 3
C. 1, 3 and 4
D. 1, 2, 3 and 4
B
Light, carbon dioxide, chlorophyll and water are required for photosynthesis.
[T/F]
In plants, leaves are the main site of photosynthesis.
T
[Blanks filling]
The morphology (形態) of the leaf, the structures of the leaf and the distribution of chloroplasts in the cells are well adapted to maximize the absorption of ______, facilitate ______ exchange, facilitate _________ of materials or reduce ______ ______, such that photosynthesis can occur at a higher rate.
light; gas; transport; water loss
[Blanks filling]
Feature and adaptation of whole leaf:
- Leaf blade is ______ and ______ → provides a large surface area for _________ _________
- Leaf is thin → ______ and ______ can reach the
photosynthetic cells easily
Feature and adaptation of whole leaf:
- Leaf blade is {broad} and {flat} → provides a large surface area for {absorbing sunlight}
- Leaf is thin → {Gases} and {light} can reach the photosynthetic cells easily
[Mixed]
Feature and adaptation of palisade mesophyll:
- Consists of ( tightly / loosely ) packed cells that contain many _________
- Located on the ( upper / lower ) side of the leaf (exposed directly to sunlight)
→ Allows effective absorption of _________
Feature and adaptation of palisade mesophyll:
- Consists of {tightly} packed cells that contain many chloroplasts
- Located on the {upper} side of the leaf (exposed directly to sunlight)
→ Allows effective absorption of {sunlight}
[Mixed]
Feature and adaptation of spongy mesophyll:
- Consists of ( tightly / loosely ) packed cells with many ______ ______
- The cells contain chloroplasts which is ( more / fewer ) than that of _________ mesophyll
→ Allows ______ to diffuse freely inside the leaf
→ Allows absorption of _________
Feature and adaptation of spongy mesophyll:
- Consists of {loosely} packed cells with many {air spaces}
- The cells contain chloroplasts which is {fewer} than that of {palisade} mesophyll
→ Allows {gases} to diffuse freely inside the leaf
→ Allows absorption of {sunlight}
[Mixed]
Feature and adaptation of upper epidermis and lower epidermis:
- Covered by a thin layer of ______ ______
→ Reduce water ( gain / loss ) from the leaf, so that water is kept inside for ___________ and keeping the cells turgid to _________ the leaf blade
Feature and adaptation of upper epidermis and lower epidermis:
- Covered by a thin layer of {waxy cuticle}
→ Reduce water {loss} from the leaf, so that water is kept inside for {photosynthesis} and keeping the cells turgid to {support} the leaf blade
[Mixed]
Feature and adaptation of stoma (in epidermis):
- More on the ( upper / lower ) epidermis
- Surrounded by a pair of ______ cells (containing chloroplasts)
→ ( Opens / Closes ) when the conditions are favourable for photosynthesis; ( opens / closes ) when the conditions are less favourable. This regulates the passage of ______ and ______ ______ into and out of the leaf
Feature and adaptation of stoma (in epidermis):
- More on the {lower} epidermis
- Surrounded by a pair of {guard} cells (containing chloroplasts)
→ Opens when the conditions are favourable for photosynthesis; closes when the conditions are less favourable. This regulates the passage of {gases} and {water vapour} into and out of the leaf
