B4: Photosynthesis Flashcards Preview

DS 7F Science 2 > B4: Photosynthesis > Flashcards

Flashcards in B4: Photosynthesis Deck (25)
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1
Q

Why is the top surface of a leaf waxy?

A

To stop water escaping from the leaf.

2
Q

Which gas diffuses into a leaf?

A

Carbon dioxide

3
Q

Why are there fewer chloroplasts in the cells of the bottom side of a leaf?

A

Because sunlight mainly hits the top of leaves so chloroplasts aren’t needed on the bottom as much.

4
Q

Stomata (holes) in leaves are opened and close by special cells called…

A

……..guard cells

5
Q

How does being thin help a leaf to carry out photosynthesis?

A

Gases can move in and out of the leaf easily.

6
Q

Why is a leaf normally dark green on top but lighter on the bottom?

A

There are fewer chloroplasts on the bottom so there is less chlorophyll.

7
Q

How do gases and water get in and out of a leaf?

A

Through holes called stomata

8
Q

What is the name of the tube that carries glucose around the plant?

A

Phloem tubes

9
Q

How is the structure of a leaf suited to carry out photosynthesis?

A
  • Contain chlorophyll to capture sunlight.
  • They are thin
  • They have a large surface area
  • They have veins
10
Q

How do veins help a leaf to carry out photosynthesis?

A

They are made from xylem tubes which can transport water for photosynthesis to take place.

11
Q

How does a large surface area help a leaf to carry out photosynthesis?

A

A large surface area can absorb as much light as possible.

12
Q

Which gases are made during photosynthesis and diffuse out of a leaf?

A

Oxygen

(Water vapour)

13
Q

By which process do plants produce their own food?

A

Photosynthesis

14
Q

What is the equation for photosynthesis?

A

Carbon dioxide + water (+ sunlight) –> glucose + oxygen

15
Q

Name the reactants of photosynthesis.

A

carbon dioxide + water

16
Q

Name the products of photosynthesis.

A

glucose + oxygen

17
Q

Where does photosynthesis take place inside plant or algal cells?

A

Within the chloroplasts

18
Q

What is the name of the green pigment found inside chloroplasts?

A

Chlorophyll

19
Q

What does chlorophyll do?

A

Absorbs light energy from the Sun

20
Q

Describe the journey of water through a plant.

A
  1. Water enters through the root hair cells of the roots.
  2. Water travels through tubes called xylem tubes
  3. Water evapourates out of the leaves.
21
Q

Why do roots not contain chloroplasts?

A

Because they are underground and so cannot capture sunlight.

22
Q

Plants store the glucose produced in photosynthesis as…

A

……..starch

23
Q

Describe (step-by-step) can we test a leaf to see if it has been photosynthesising?

A
  1. Remove the waxy cuticle with boiling water
  2. Remove the chlorophyll with hot ethanol
  3. Drop iodine on to leaf
  4. If the iodine turns blue/black - starch is present
  5. This means the leaf has been photosynthesising
24
Q

What colour does iodine change to if starch is present?

A

From orange to blue/black

25
Q

If a plant is lacking in magnesium it might be pale in appearance. Can you explain this?

A

Magnesium is a mineral needed by plants to make chlorophyll. The plant would be lacking in chlorophyll and appear pale.