Dicot Plant Flashcards
Name all the part of a leaf
- cuticle
- upper epidermis cells
- palisade mesophyll cells
- spongy mesophyll cells
- sub-stro matal air space
- lower epidermas cells
- guard cells
- stomata
Why is the spongy mesophyll made up of irregular cells
It will increase their sa:v ratio
What 2 major reactions take place in plants
- respiration
- photosynthesis
Word equation for photosythesis
Carbion dioxide + water —> glucose + oxygen
Word equation respiration
Glucose + oxygen —> energy + carbon dioxide + water
What is movemnemt of 02 in dim light through a dicot plant
- 02 moves in via diffusion
- 02 moves via diffusion and dissolves in layer of moisture
- 02 oves into cytplasm of the cell
What is the rate of respiration in plant low in dim light
- not enough light for photosynthesis so the rate photosynthesis is too low to supply 02 needed for the plant to respire
Movment of 02 in strong light
- Co2 willl diffuse in and 02 out
- diffusion gradient is maintained
What is the role for stomata
Gas exchange can occur when through them to provide for metabollic needs
What happens in a plant when too much water is lost
- guard cells become shrunken
- stomata close
Both of these things combined will reduce then volume of water lost through transpiration
Define transpiration
Evaporation of water from leaves of a plant
What increases transpiration
- high temperature
- low humity
- air flow
- light
How does a high temperature increase transpiration
It increases kentic energy
How does low humity increase transpiration
There’s a high water potential differnece
How does air flow increase transpiration
Maintains water potential gradient
Why does light increase transpiration
Stomata will open
Why would more water be lost from a plant
If theres a larger water potential gradient btween inside and outside of stomata
Smaller wp gradient means
Slower rate of diffuson
Larger wp gradient means
Faster rate of diffusion
Define hydrophytes
Plants that live in enviroment where lots of water is available
Define mesophytes
Live in an enviroment with moderate amount of water
Define xerophytes
Plants that live in a enviorment where low water availability
How are xerophytes adapted to reduce water loss
- thivk cuticle
- rolled up leaves
- hairy leaves
- stomata in pits or grooves
- Reduced sa:v of leaves
- extensive root system
What does the thick cuticle effect and why
The diffusion distance because of the thickness less water can escape
What do rolled up leaves effect and how
Concentration gradient because the rolled up leaves protect the lower epidermis traps air which becomes saturated with water vapour which has a high water potential wich means ther is no water potential gradient between inside and out so no water is lost
What do hairy leaves effect and how
The concentration gradient the hair traps moisture which reduces the wter potential gradient beween outside and inside so less water lost by evaportion
What does a reduced sa:v effect and how
- small sa:v ratio = slower diffuson which means water loss is reduced
How is SA made big
- air spaces in contact with mesophyll cells
- leaf has a large internal SA compared to V
How is the CG made big
- many stomata
- O2 and CO2 diffuses in and out of cell
- air spaces in leaf connect to outside
How is the DD small
- cell walls are thin and permeable
- mesophyll cells are close to stomata
