Plants Flashcards
how is glucose stored
This glucose is used in many ways, and can also be stored
it is stored as starch
why do plants photsynthesise
Plants photosynthesise to generate their own glucose
why is starch a good storage molecule
Starch is a good storage molecule of glucose because it is insoluble, large, compact, and it can be broken down easily
Why is it that photosynthesis happens in all the green parts of the plant?
Because chloroplasts are the site of photosynthesis and all chloroplasts contain a green pigment called chlorophyll. Chlorophyll is the site of photosynthesis so all green parts are able to photosynthesise
what test can you tes with to show that the green parts of a plant photsynthesise
You can show that photosynthesis is only happening in the green areas of the plant by conducting the iodine-starch test
explain the iodine starch test to probet he green parts photsynthesise
Get a leaf that has green and non-green areas
The non-green areas will give a negative result, whilst the green areas will stain blue-black
how do you de starch a plant
To de-starch a plant, place it in the dark for 2-3 days
if you leave a plant in the dark, why does the starch disapear
As it is in the dark, the plant is unable to photosynthesise to produce glucose, so in order to sustain life, it uses its glucose reserves for respiration
Design a practical to show that CO2 is needed for a plant to photosynthesise (3)
Place the plant in a jar lined with soda lime (calcium carbonate) with a lot of light
The soda lime will remove all CO2 from the air
The plant will not be able to photosynthesise - can be confirmed with the starch test
Waxy cuticle/upper epidermis define
transparent to let the light through. It is a barrier against pathogens. Reduces water loss by evaporation
Palisade mesophyll layer - define
palisade cells, which are the main site of photosynthesis as they contain lots of chloroplasts. Palisade mesophyll layer is at the top to maximise the amount of sunlight it can get
Spongy mesophyll layer - define
has lots of air spaces to maximise the rate of gas exchange by allowing gases to diffuse in and out. Absorbs carbon dioxide and releases O2 and water vapour
Lower epidermis - define
contains holes called stomata. Stomata are opened and closed by guard cells which do this by changing their shape. Lets gases in and out
what makes up the vascular bundle
ascular bundle - xylem and phloem.
Xylem -define
transports water and mineral ions - water is moved via the transpiration stream. In leaves, water leaves the xylem and supplies the mesophyll cells
