Plant growth L14/15 Flashcards
What are apical meristems?
Structures for growth of roots and shoots
What is different about plant and animal cell division
The process of cytokinesis differs due to the cell wall, as it uses a phragmoplast to transport and organize vesicles forming the cell plate
Where is the primary cell wall synthesized?
Between plasma membrane and middle lamella
During cytokinesis what does the trapped smooth endoplasmic reticulum become?
Plasmodesmata
What is the direction of cell elongation?
Perpendicular to direction of cellulose microfibrils
Define indeterminate growth
Plants grow throughout their lives, and the growth region is always able to grow, its only limiting factor is environmental
What is the role of and location of apical and lateral meristems?
Apical meristems in shoots and roots contribute to primary growth
Lateral meristems contribute to secondary growth - important in trees
Define and summarize SAM
Shoot apical meristem, most distal region of a stem or branch
produces undifferentiated cells, which are differentiated based on location
Define and summarize RAM
Root apical meristem
Near root tip, behind the root cap
What defines the tunica layers in SAM, what do they do?
2 outermost layers
Cells divide in anticlinal planes (perpendicular to apical dome)
Causes increase in diameter
What defines the corpus in SAM? what is its function?
L3- innermost layer
leads to growth
cells divide in periclinal planes
pushes shoot upwards
What is the importance of root hairs?
They increase surface area for nutrient absorption
Derived from individual epidermal cells
develop in zone of differentiation
What is secondary growth?
Horizontal- diameter growth typically only found in trees
What do the vascular and cork cambium become in growth?
Vascular - inner bark
Cork - outer growth
What is the use of old secondary xylem in trees? what is it called?
Storage of various nutrients, slows decomposition
Heartwood
