PLANTS Flashcards
Vein (Vascular bundle)
- Transports water and other substances
- Contains xylem and phloem
Guard Cells
- Occur in pairs around stomata
- Regulate opening and closing of stomata
Upper epidermis
- Top part of leaf surface
- Transparent so light can penetrate
Lower epidermis
- Lower part of leaf
- Contains lots of stomata
Palisade mesophyll
- Tightly packed parenchyma cells
- Rich in chloroplasts therefore most photosynthesis occurs here
- Found beneath upper epidermis
Spongy mesophyll
- Irregularly shaped parenchyma cells
- Found beneath palisade cells
- Lots of air spaces between allow O2 CO2 and H2O to move around easily
*
Cuticle
- Waxy layer on upper epidermis
- Prevents water loss
Apical meristem
- Undifferentiated cells at tips of roots
- Here cells will divide & allow plants to grow longer and develop specialized tissues
Lateral meristem
- (cambium) – cylindrical regions in roots and stems that increases the diameter of the plant. Responsible for secondary growth
Secondary growth
- growth at lateral meristems, increasing diameters of roots and stems from 2nd year of life on.
Where is the stomata located? Why? What is their function?
Stomata
* Found on the underside of the leaf
* They are found on the underside of the leaf because…
1. Reduces water loss
1. Allows packing of more cells that can do photosynthesis on the upper layer
1. Reduces chances of entry of foreign organisms
* The stomata’s function is to allow gas exchange, including water vapour
Where are the guard cells located? Why? What is their function?
- Guard cells occur in pairs around the stomata
- The guard cells regulate the opening and closing of stomata
Evaporation
the process of turning from liquid into vapour
Transpiration
The exhalation of water vapor through the stomata.
Cohesion
The force of attraction between the water molecules in each xylem tube provides force that keeps the water column unbroke while being pulled up
Adhesion
Cause the water molecules to stick to the xylem walls. Adhesion keeps the water column from breaking as it is pulled upward
Xylem
xylem transports water and minerals from roots to shoots, providing structural support
Phloem
transports organic nutrients in both directions
Identify the major location of photosynthesis in leaves and why this occurs.
- inside the chloroplasts that sit in the mesophyll of the leaves
- a way of producing energy for the plant
Vascular bundle arrangement of stems (monocot and dicot)
Dicot: x shape
Monocot: circle shape
Vascular bundles arrangement of roots (monocot and dicot)
Dicot: circle
Monocot: random
Trace the pathway of water and sugars in a plant
- Sucrose enters the phloem in the leaf, increasing concentration.
- Water enters the phloem because of the higher concentration.
- Water entry raises pressure in the phloem.
- Pressure difference causes solution to flow from leaf to stem and root.
- Water moves in and out of the phloem along the way.
- Sucrose is taken out of the phloem by stem and root tissues.
- Sucrose removal lowers concentration in the phloem.
- Water exits the phloem as sucrose concentration drops.
- Pressure in the phloem decreases.
