B4 - Organising Animals And Plants (plants) Flashcards
What is the use and adaptation of epidermal tissues?
The epidermal tissue have a lot of chlorophyll to absorb as much sunlight as possible for photosynthesis
What is the use and adaptation of palisade mesophyll?
These cells are tall and packed together closely to absorb as much light as passible - they contain many chloroplasts
What is the use and adaptation of spongy mesophyll?
They capture light to make food - they have air spaces between them to allow easy gas exchange
What do xylem cells do?
Xylem cells transport water through the plant
What do phloem cells do?
Phloem cells transport dissolved food
What is the meristem tissue?
The plants stem cells are contained in the meristem tissue, which is found at the growing tips of shoots and roots
What is translocation?
The movement of dissolved sugars from the leaves to the rest of the plant through the phloem
What is transpiration?
Transpiration is the evaporation of water from the aerial parts of the plants (mostly from open stomata on the lower epidermis of leaves). NOT TO BE CONFUSED WITH TRANSPIRATION STREAM, which is the transportation of the water from the roots, through the stem and onto the leaf
What factors affect transpiration?
Any from: Light intensity Air currents Temperature Humidity Number of leaves
How do stomata open?
To open, guard cells around the stoma take in water and become turgid (hard and swollen) and the expand open
How do stomata close?
To close, guard cells surrounding the stoma lose water and become flaccid (soft and wrinkly) and they deflate closed
What are the function and adaptations of stomata?
Stomata, when open, allow ions, carbon dioxide and water in - they take oxygen and water out. They’re on the underside of the leaf to prevent extreme water loss by transpiration. Guard cells control whether the stomata are open - they are two guard cells around each stoma. Guard cells have different sized cell walls to make it easier for the stomata to open
