Igcse 2010 REVISION photosynthesis

IGCSE Revision QuestionsPhotosynthesis

Mainly based on the exercises from http://www.biology-resources.com/biology-questions.html

http://biodeluna.wordpress.com

To start with:

The Photosynthesis Song from Simple Science on Vimeo.

Found athttp://www.clickbiology.com/onlyphotosynthesis-song/

Which of these statements is most accurate?

In bright sunlight a green plant will be

1. photosynthesising only

2. respiring only

3. photosynthesising and respiring

4. taking in oxygen and giving out CO2

Which of these statements is most accurate?

In bright sunlight a green plant will be

1. photosynthesising only

2. respiring only

3. photosynthesising and respiring

4. taking in oxygen and giving out CO2

Equation which summarises the process of photosynthesisphotosynthesis

6CO2 + 6H2O C6H12O6 + 6O2

glucose

Photosynthesis (from the Greek φώτο- [photo-], "light," and σύνθεσις [synthesis], "putting together", "composition") is a process that converts carbon dioxide into organic compounds, especially sugars, using the energy from sunlight

http://en.wikipedia.org/wiki/Photosynthesis

http://en.wikipedia.org/wiki/Greek_language

http://en.wikipedia.org/wiki/Carbon_dioxide

http://en.wikipedia.org/wiki/Organic_compound

A leaf is detached from a tree and tested with iodine. The leaf turns dark blue. (a) What does this result tell you?

(b) (b) Why is this result not sufficient evidence to confirm that photosynthesis had taken place in the leaf?

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(b) Why is this result not sufficient evidence to confirm that photosynthesis had taken place in the leaf?


Starch is present.


(b) Why is this result not sufficient evidence to confirm that photosynthesis had taken place in the leaf?


Starch is present.

Unless the leaf is known to have been free from starch at the beginning of the experiment you cannot conclude that photosynthesis has occurred. The starch might be permanently present in this leaf. Also, in the absence of an experimental design (with a a controlcontrol), there is no telling where the starch has come from. It might have been produced from sucrose which was transported to the leaf from another part of the plant.

What 4 things might affect the rate of photosynthesis?

http://www.s-cool.co.uk/gcse/biology/photosynthesis/test-its/photosynthesis-exam-testit.html

What 4 things might affect the rate of photosynthesis?

• water • carbon dioxide • sunlight • temperature


Name the regions A to D.


Name the regions A to D.


A is a Palisade Cell B is a Guard CellC is a StomaD is Air Space

• What additional substances does a plant need to make amino acids and proteins from glucose?

• Where do these substances come from?



To make amino acids and proteins from glucose, a plant needs a supply of nitrate (for nitrogennitrogen)

and sulphate (for sulphursulphur).



To make amino acids and proteins from glucose, a plant needs a supply of nitrate (for nitrogennitrogen)

and sulphate (for sulphursulphur).

These substances come from the soil.from the soil.

Which of these processes increase the concentration of carbon dioxide

in the atmosphere?

(a) Respiration(b) Photosynthesis

(c) Combustion

(d) Decay

Which of these processes increase the concentration of carbon dioxide

in the atmosphere?

(a) Respiration(b) Photosynthesis

(c) Combustion

(d) Decay

Why do plants store some of the sugar they make as starch?


Why do plants store some of the sugar they make as starch?

• Plants could use starch or glucose. Starch is insoluble, while glucose is soluble.

• This means that if starch is used, less water is required to keep its food stored.


What gases will be taken in and given out by a green plant

• (a) in darkness,

• (b) in bright sunlight?

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What gases will be taken in and given out

by a green plant• (a) in darkness,



taking in oxygen and giving out carbon dioxide.

What gases will be taken in and given out

by a green plant• (a) in darkness,



taking in oxygen and giving out carbon dioxide.

taking in carbon dioxide giving out oxygen

Water vapour will also be escaping from the leaf; more so in sunlight.

The process of aerobic respiration requires

1. A food source, oxygen, enzymes, a blood supply

2. A food source, carbon dioxide, enzymes

3. Oxygen, enzymes, sunlight

4. A food source, oxygen, enzymes

The process of aerobic respiration requires

1. A food source, oxygen, enzymes, a blood supply

2. A food source, carbon dioxide, enzymes

3. Oxygen, enzymes, sunlight

4. A food source, oxygen, enzymes

Fill in the missing words...• Water moves from the soil into

the roots by ___(i)___ and then flows steadily up the ___(ii)___. As water is lost from the leaf by ___(iii)___ more water is drawn up through the ___(iv)___ to replace it. The roots have root ___(v)___ to increase their ___(vi)___ and so allows more water to be absorbed.

http://www.s-cool.co.uk/gcse/biology/plant-growth/test-its/plant-growth-exam-testit.html

Fill in the missing words...• Water moves from the soil into the

roots by ___(i)___ and then flows steadily up the ___(ii)___. As water is lost from the leaf by ___(iii)___ more water is drawn up through the ___(iv)___ to replace it. The roots have root ___(v)___ to increase their ___(vi)___ and so allows more water to be absorbed.

http://www.s-cool.co.uk/gcse/biology/plant-growth/test-its/plant-growth-exam-testit.html

(i) osmosis;

(ii) xylem;

(iii) transpiration;

(iv) xylem;

(v) hairs;

(vi) surface area.

http://es.dreamstime.com/foto-de-archivo-smiley-del-emoticon-image11812570

Igcse 2010 REVISION photosynthesis

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