B5.2 Plant structure Flashcards
List the structures of a leaf
- Chloroplasts
- Cuticle
- Guard cells and stomata
- Upper and lower epidermis
- Palisade mesophyll cells
- Spongy mesophyll cells
- Stomata
- Vascular bundles
- Xylem
- Phloem
Functions of waxy cuticles
It provides waterproofing and reduces water loss from the leaf without reducing light absorption
Function of chloroplasts
Chloroplasts contain chlorophyll which allows light energy to be absorbed and converted to chemical energy
Functions of the upper and lower epidermis
The epidermis acts as a protective barrier around the leaf to prevent pathogens from entering and causing harm to the organism. Epidermis cells are transparent to let light pass through and do not contain chloroplasts.
Functions of the spongy mesophyll cells
Cells are loosely spaced and have a large surface area to allow rapid gas exchange of CO2 and oxygen when the stomata is open
Functions of the xylem
Transports water and minerals to the leaf from the roots in transpiration.
They have a thick cell wall to provide structural strength
Function of the phloem
Transports sucrose and amino acids up and down the plant in translocation
List the 2 minerals in plants
- Nitrate ions
- Magnesium ions
What would happen to a plant if it lacks nitrogen?
Nitrate ions are used in the plant to build amino acids, and thus proteins and enzymes. Without nitrate ions the plant would not be able to grow or repair itself. Therefore, it will suffer from stunted growth and yellowing leaves
What will happen to a plant if it lacks magnesium ions?
Since magnesium ions are used to make chlorophyll, a lack of magnesium ions will lead to a lack of chlorophyll, meaning that photosynthesis cannot occur. Therefore, the plant will suffer from yellow leaves (between the veins).
What is the top layer of a leaf?
Waxy cuticle
What is underneath the waxy cuticle in a leaf?
Palisade mesophyll cell layer
Where is the spongy mesophyll layer located in a leaf?
Underneath the palisade layer
