Photosynthesis

Question 1

What substance in the chloroplasts absorbs sunlight

Answer 1

Chlorophyll

Question 2

What is the photosynthesis equation

Answer 2

(+ light energy)

Carbon dioxide + water —————> glucose + oxygen

Question 3

What 3 steps are involved in photosynthesis

Answer 3

1) Co2 is taken in by leaves, and water is taken up by the roots
2) The chlorophyll traps the light energy needed for photosynthesis
3) the energy is used to convert the co2 and water into glucose

Question 4

What is released as a by-product of photosynthesis

Answer 4

Oxygen

Question 5

What is some of the glucose produced into from photosynthesis

Answer 5

Insoluble starch for storage

Question 6

How can you identify whether photosynthesis has taken place

Answer 6

Testing leaves with iodine solution should of blue black in the presence of starch

Question 7

Which parts of a variegated leaf will go blue black with iodine solution

Answer 7

The bits with green patches as they contain the chlorophyll

Question 8

Why would a lack of light limit photosynthesis

Answer 8

The light provides the energy required for the process to occur

Question 9

Which organisms can photosynthesise?

Answer 9

Green plants and algae

Question 10

Why may Coke weather limit photosynthesis

Answer 10

If it’s too cold the enzymes do not work effectively so slow the process down

Question 11

How will co2 levels affect photosynthesis

Answer 11

Too little co2 will slow photosynthesis down; enclosed spaces eg in a greenhouse have little co2 on a sunny day where there is plenty of light but plants run out of co2

Question 12

What is a limiting factor

Answer 12

A factor which puts a cap on the rate of photosynthesis

Question 13

What is an independent variable

Answer 13

The one being controlled eg co2 concentration

Question 14

What should you take into account when conducting experiments on how factors affect photosynthesis

Answer 14

You need to know which factor is being changed and which is controlled,if you want to investigate the effect of increasing co2 levels then you must be aware that other factors such as light limit the rate of photosynthesis

Question 15

What is a depending variable

Answer 15

The one you measure, eg volume of oxygen produced

Question 16

Which variables will need to be controlled if investigation co2 concentration and volume of oxygen produced

Answer 16

Light, temperature and the type of plant

Question 17

What is the graph for co2 concentration against rate of photosynthesis

Answer 17

As co2 increases ROP increases but eventually another factor becomes the limiting factor

Question 18

What does a graph of light intensity against ROP look like

Answer 18

As light intensity increases ROP increases

Question 19

What will a graph of temperature against ROP look like

Answer 19

As temp increases ROP increases until a certain point when the enzymes are destroyed and the reaction stops completely

Question 20

How may the soluble glucose produced from photosynthesis in plants be used

Answer 20

Converted into insoluble starch for storage
Used for reparation
Converted into fats and oils for storage
Used to produce cellulose which strengthens cell walls
Used to produce proteins

Question 21

What else do plant and algae cells also need a supply of? And for what?

Answer 21

Mineral ions such as nitrate ions in order to produce protein

Question 22

Where do plants get nitrate ions from?where do algae get nitrate ions from?

Answer 22

Soil Water they live in

Question 23

What do farmers have to evaluate when picking the best conditions for their plants to grow in

Answer 23

They have to evaluate the benefits of increased growth and the cost of heating and lighting or providing co2

Question 24

What can be constructed to grow plants in an enclosed space

Answer 24

Greenhouses and polytunnels

Question 25

What does a grower have to compare to test a greenhouse or polytunnels

Answer 25

The biomass of plants grown inside and out without the extra factors

Question 26

What factors must be controlled in a greenhouse to improve plant growth

Answer 26

Co2, temp, light

Question 27

How may temp affect distribution of organisms

Answer 27

Arctic plants are small which limits the number of plant eaters which can survive in the area

Question 28

How may availability of nutrients affect distribution

Answer 28

Most plants struggle to grow when mineral ions are in short supply and so few animals can survive in that area

Question 29

How may amount of light affect distribution of organisms

Answer 29

Few plants live on a forest floor because the light is blocked by the trees shaded plants often have bigger leaves so more chlorophyll

Question 30

How may availiabitliy of water affect distribution

Answer 30

Water is important for all organisms so few will live in a desert. If it rains in the desert then plant grow, produce flowers and seeds very quickly. There will be more food for animals

Question 31

How may availability of oxygen affect distribution

Answer 31

Water animals can be affected by lack of oxygen some invertebrates can live at very low oxygen levels, but most fish need high levels of oxygen dissolved in water

Question 32

How may availability of co2 affect distribution

Answer 32

Lack of co2 will affect plant growth and consequently the food available for animals

Question 33

How ça quantities data be obtained

Answer 33

Random quanta give sampling with a quadrat | Sampling along a transect

Question 34

What is a quadrat

Answer 34

A square frame which is subdivided into a grid

Question 35

When would a quadrat be useful

Answer 35

If you wanted to estimate the number of a certain plant in a whole field

Question 36

Why is sample size important?

Answer 36

In a large field enough quadrats must be placed to be representative of the whole field and is usually given as a mean per square

Question 37

When is it good to use a transect

Answer 37

Investigating the distribution between 2 points, physical factors can also be measured at each quadrat point

Question 38

What is a transect

Answer 38

A line marked between 2 point where a quadrat is placed at regular intervals to measure distribution

Question 39

What is a valid investigation

Answer 39

An investigation where all possible variables are controlled

Question 40

She is a measurement considered repeatable

Answer 40

When the same experimanter repeats the investigation using the same method and obtains the same results

Question 41

Why is it necessary to check that the result are reproducible

Answer 41

Bu using a different person, equipment you can see if you get the same results because an experimenter may make the same mistake over and over but still get the same results

Question 42

When is an experiment considered reproducible

Answer 42

If the experiment is reoeated by another person, or using different equipment or technique and the same results are obtained

Question 43

How can you make sure an investigation is valid

Answer 43

Only the independent variable should affect the results all other variables must be controlled