Photosynthesis

Question 1

What is the word equation for:

Photosynthesis

Answer 1

light intensity
Water + carbon dioxide –> glucose + oxygen

Question 2

What is the chemical equation for:

photosynthesis

Answer 2

6H2O + 6CO2 –> 6O2 + C6h12O6

Question 3

Where does:

photosynthesis take place

Answer 3

Chloroplasts

Question 4

What are in:

Chloroplasts

Answer 4

Chlorophyll

Question 5

What is the purpose of:

Chlorophyll

Answer 5

To absorb light energy

Question 6

What are the reactants for:

Photosynthesis

Answer 6

1. Carbon dioxide
2. Water

Question 7

What are the products of:

Photosynthesis

Answer 7

1. Glucose
2. Oxygen

Question 8

What is the:

Energy Transfer in Photosynthesis

Answer 8

Light energy –> Chemical energy

Question 9

How does:

Oxygen enter the leaf

Answer 9

1. Diffusion
2. through the stomata
3. from high concentration outside the leaf
4. to low concentration in the leaf

Question 10

How is:

Water absorbed by the Plant

Answer 10

• Osmosis
• Root hair cell

Question 11

How are:

Mineral ions absorbed

Answer 11

• By the roots
• Active transport and diffusion

Question 12

What are the:

Main limiting factors of photosynthesis

Answer 12

• Light intensity
• Carbon dioxide concentration
• Temperature

(Water is a limiting factor but is not a main one, usually not the case)

Question 13

What is the worst:

Colour of Light for photosynthesis

Answer 13

• Green
• Chloropyll cannot absorp green light
• Light intensity will become the main limiting factor

(leafs are green because chlorophyll reflects green light)

Question 14

What are the best:

Colours of Light for photosynthesis

Answer 14

• Red and blue
• Chlorophyll abosrbs these colours best

Question 15

What is a:

Limiting Factor

(When it comes to photoshynthesis)

Answer 15

A factor which limits the rate of photosynthesis.

Question 16

How is Photosynthesis affected by:

Temperature

Answer 16

1. ↓ temperature –> ↓ kinetic energy –> ↓ collisions
2. Optimum temperature –> ↑ kinetic –> ↑ collisions
3. ↑ temperature –> enzymes denature –> enzyme-substrate complexes cannot form anymore

Question 17

What are the different:

Structures in a Leaf

Answer 17

• Waxy Cuticle
• Upper Epidermis
• Palisade Mesophyll
• Spongy Mesophyll
• Lower epidermis
• Guard cells
• Stomata

Question 18

What is the purpose of the:

Waxy Cuticle

Answer 18

• Water-proof layer to prevent water loss to keep plants turgid
• otherwise they would be flaccid as water would evaporate
• This would lead to the shrinking of the cell vacuole leading to the plant being weak and soft

Question 19

What is the purpose of the:

Upper Epidermis

Answer 19

Transparant layer to allow light to go through to the palisade layer, where the chloroplasts are

Question 20

What is the purpose of the:

Palisade Mesophyll

Answer 20

• Contains chlorophyll needed for Photosynthesis
• Chloroplasts are site of photosynthesis

Question 21

What is the purpose of the:

Spongy Mesophyll

Answer 21

Cells are not tightly packed creating lots of air spaces. Air spaces increase the surface area to volume ratio of the leaf and reduce the diastance of the diffusion pathway increasing the number of cells in contract with the gases exchanged

Question 22

What is the purpose of the:

Guard cells

Answer 22

Control the opening and colsing of the stomata. They open during the day and close at night when photosynthesis is not needed to redcue water loss.

Question 23

What is the purpose of the:

Stomata

Answer 23

Allow for the diffuison of gases in and out of the leaf. Present only on the lower side of the leaf and so as to reduce water loss.

(top of leaf would have high levels of evaporation as it is usually warmer)

Question 24

Why are:

Leaves broad?

Answer 24

So that there is a large surface area to be exposed to higher volumes of light

Question 25

# What are the uses of: Glucose in a Plant

Answer 25

1. Sucrose for fruits 2. respiration 3. active transport, more nitrogen, proteins 4. celluose for cell wall 5. starch food store 6. fats and oils can be stored or used for growth

Question 26

# How do you: Destarch a leaf

Answer 26

keep it in the dark for 2 days

Question 27

# What are: Variegated leaves

Answer 27

Leaves that have chlorophyll in only certain parts of the leaf

Question 28

# How to: Test a leaf for starch

Answer 28

1. Boil water with a bunsen burner 2. Put the leaf in the boiling water for 1 minute 3. Turn bunsen burner off 4. put leaf in test tube full of ethanol in boiling water for 10 minutes for the leaf to decolorise 5. Test for starch using iodine

Question 29

# What is: Nitrate used for | (in plants)

Answer 29

* Contains nitrogen for amino acids and proteins which is needed for growth * If there is not enough, leaves will turn yellow

Question 30

# What are: Phosphates used for | (in plants)

Answer 30

* For making DNA, membranes, respiration and growth * If there is not enough, poor root growth and purple leaves

Question 31

# What is: Magnesium used for | (in plants)

Answer 31

* Needed to make chlorophyll * If there is not enough, leaves will turn yellow

Question 32

# What is: Potassium used for | (in plants)

Answer 32

* To help enzymes which are needed for both photosynthesis and respiration * If there is not enough, there will be poor flower and fruit growth and discoloured leaves

Question 33

# Why do: Plants die in waterlogged areas?

Answer 33

If the roots are waterlogged there is less oxygen, anaerobic respiration happens...

Question 34

# What is the: Vascular bundle made out of

Answer 34

Xylem and Phloem

Question 35

Xylem characteristics

Answer 35

* Hollow, dead cells to form a continuos tube * Transports water and minerals up the plant * Is held together by rings of strong waterproof lignin * Is in the centre of the vascular bundle

Question 36

Phloem characteristics

Answer 36

* Transports sugars and food molecules around the plant * movement of these molecuels is called transolocation * can move either up or down * made of living cells * companion cells provide the ATP for the phloem sieve tube cells * The end walls of the tube cells have pores through which food is transported from cell to cell - this is called the sieve plate

Question 37

Why do Multicelluar organisms like plants need a transport system?

Answer 37

Complex Multicelluar organisms need to transport nutrients and gases over a large distance