Lecture 3-4: Anatomy and Morphology - 10/6 Flashcards
Function of roots
Anchor the plant
Absorb minerals and water
Storing organic nutrients
Synthesize organic molecules and hormones
Taproot
One main vertical root that gives rise to some large lateral roots, called branch roots
Fibrous roots
Many thin lateral roots with no main root
Adventitious roots
Arise from stems and leaves
What are the various zones present in roots?
Zone of maturation
Zone of elongation
Zone of cell division
Which zone do root hairs form?
The zone of maturation, since otherwise they would break as the root gets longer (if they grew in the zone of elongation)
Casparian strip
Bands of waterproof material around cells that make up the endodermis (interior of leaf, in this context). They force water to go through a symplastic route instead of an apoplastic route. This is important because cells can only control the movement of water in the symplastic route
Where do lateral roots come from?
The pericycle. This allows for an easy connection to the vascular cylinder
Epidermis
The outermost layer of tissue in a stem/root
Endodermis
In seed plants, an inner layer of cells between the cortex and pericycle cells that surrounds the vascular bundle.
Has Casparian strips that regulate water movement (and also other chemicals)
Pericycle
A thin layer of plant tissue between the endodermis and vascular components of roots (at least in young di/monocot roots)
Cortex
An inner layer of tissue inbetween the epidermis and vascular tissue of a stem/root
Shoot apical meristem
Dome-shaped mass of dividing cells at the shoot tip
Axillary buds
Develop from meristematic cells left at the bases of growth tips, from which lateral shoots may develop
Dicot external structures
Stipules, petiole (monocot grasses don’t have these), leaf blade, midvein, lateral veins
