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Flashcards in Photosynthesis + Plants Deck (41):

What is the symbol equation for photosynthesis?

6CO2 + 6H2O -> C6H12O6 + 6O2
(Note: you must put light energy and chlorophyll on the arrow)


What is the simplest way to test for whether photosynthesis has taken place?

Test for starch. (as it is a product of photosynthesis) However this is said to be a qualitative test as it only shows whether photosynthesis has or hasn't taken place.


What's the best way to test how much photosynthesis has taken place?

You can measure the amounts (volumes) of oxygen, so the production of oxygen can be used as a quantitive test for photosynthesis.


What is photosynthesis?

Photosynthesis is the fundamental process by which plants manufacture carbohydrates from raw materials using energy from light


What is chlorophyll?

A green pigment in plants that is responsible for the absorption of light to provide energy.


What is the waxy cuticle for on a leaf?

It reduces water loss


What is that the epidermis on a leaf?

A covering which is usually one cell thick. It is transparent And allows light to pass and has the major function of preventing entry of disease-causing organisms.


What is the Palisade mesophyll on a leaf?

Tall, thin cells that are tightly packed near the upper layer of a leaf. They have many chloroplasts which allows the maximum absorption of light energy.


What is the vein in a leaf?

The transport system in and out of the leaf. Xylem vessels deliver water and mineral salts, and the phloem tubes carry away the organic products of photosynthesis such as glucose


What is the spongy mesophyll layer in a leaf?

Cells which are rather loosely pack allowing airspaces between them to aid diffusion of gases through the leaf.


What is a limiting factor?

Something present in the environment in such short supply that it restricts life processes


How do plants obtain the CO2 needed for photosynthesis?

CO2 diffuses into the leaves through this stomata on the underside of the leaf.


How do plants obtain the water for photosynthesis?

The water is carried to the leaves from the soil through root hairs and xylem vessels.


What is the glucose produced in photosynthesis used for?

Respiration, stored as starch, used to make cellulose, combines with mineral ions to make proteins, fats and vitamins for growth.


What happens to the oxygen produced in photosynthesis?

It is a waste product, and diffuses out of the leaf via stomata


Chlorophyll absorbs light energy. What is this light energy used for?

It is used along with enzymes to combine CO2 and H2O to make glucose.


What are the four steps for testing a leaf for starch?

1. The leaf is putt in boiling water.
2. The leaf is warmed in Ethanol until the leaf turns colourless.
3. The leaf is dipped into warm water again briefly.
4. The Leaf is placed on a white tile and iodine solution is added. Blue/black is a positive result.


What is the purpose of putting the leaf into boiling water?

To break down cell walls and stop action of enzymes. It allows easier penetration by ethanol.


What is the purpose of warming the leaf in ethanol?

To extract chlorophyll, which would mask observations later.


What is the purpose of dipping the leaf into water again briefly.

To soften he now brittle leaf to allow penetration of iodine solution.


Define the term limiting factor.

A limiting factor is something present in the environment in such short supply that it could restrict lights processes.


What are the three ways photosynthesis can be increased in greenhouses?

I burning hydrocarbons, paraffin heaters or manure.


How does burning hydrocarbons in greenhouses increase the rate of photosynthesis?

When you burn hydrocarbons (combustion) you produce CO2, H2O and heat.


How does using the manure in greenhouses increase the rate of photosynthesis?

The microbes in manure respire producing CO2 and heat.


What are nitrate ions used for in plants?

Protein synthesis


What are magnesium ions used for in plants?

Chlorophyll synthesis


What is the main danger of overuse of nitrogen fertilisers?



Describe the eight stages of eutrophication.

1. Farmers spray crops with fertilisers to help it grow.
2. Fertilisers (containing nitrates) spread into the water.
3. Water plants and algae arrive on the nutrients.
4. Algae on the surface blocks out light to the plants below.
5. The plants die due to lack of light.
6. Microorganisms (e.g. bacteria) feed on the dead plants.
7. Microorganisms rapidly multiplying and use up oxygen in respiration.
8. Fish and other aquatic animals die due to lack of oxygen.


What is the deficiencies symptoms for a plant that does not get enough magnesium ions?

Yellow leaves, magnesium is responsible for the green chlorophyll.


What are the deficiency symptoms of a plant that does not get enough nitrate ions?

Poor growth and yellow leaves, as nitrogen is responsible for the amino acids that are responsible for growth.


What is the path taken by water through a plant?

Root hair, root cortex cells, xylem, mesophyll cells.


What is transpiration?

Transpiration is the evaporation of water at the surfaces of the mesophyll cells followed by loss of water vapour from plant leaves, through the stomata.


Describe how increased temperature effects transpiration rate.

Transpiration is faster, as evaporation and diffusion is faster at higher temperatures.


Describe how we increased humidity effects transpiration rate.

Transpiration is slower, as the leaf is already surrounded by moist hair so the concentration gradient for the diffusion is shallower.


Describe how increased light intensity effects transpiration rate.

Transpiration is faster, because the stomata open wider allowing more diffusion out of the leaf.


Describe how increased wind effects transpiration rate.

Transpiration is speeded up as wind causes diffusion to be quicker


Describe how wilting occurs.

Most plant cells are turgid at all times. This supports the weight of the plant. If the plant looses water faster than it can be absorbed the cells loose turgor pressure and become flaccid. This causes the plant to wilt.


What tissue is responsible for transpiration?



What tissue is responsible for translocation?



What is translocation?

Translocation is the movement of soluble materials such as Sugars in the form of sucrose and amino acids in the phloem, from regions of production to regions of storage or to regions of utilisation in respiration and growth.


How do plants create the low water potential in their roots so that they can uptake water?

Transpiration in their leaves produces attention (pull) from above, creating a water potential gradient in the xylem, drawing cohesive water molecules up the plant.

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