Plant Development Flashcards
(51 cards)
determinate growth
plant organs stop growing after a certain size.
indeterminate growth
plants keep growing throughout their life due to meristems.
what are the 2 main meristems, where they found and what do they do?
- apical meristems -tips of roots, shoots, and in axillary buds, enables primary growth (increases height)
- lateral meristems -vascular and cork cambium, enables secondary growth (increasing girth, wideness)
apical > height like a for apex of mountain
what does vascular cambium do
-adds secondary xylem and phloem to the organ
what does cork cambium do
-replaces the epidermis with periderm as it cracks and sloughs off.
true or false most meristemic cells will remain meristemic
false, most meristemic cells will differentiate into cell types, tissues, and organs, only some remain meristemic
the root is derived from the RAM which is covered by a root cap, what does a root cap do
protects the root apical meristem from damage as the root elongates
what’s does the zone of divison in primary root growth include and produce?
- includes stem cells/initials of the RAM
- produces new root cells, including cells in the root cap (mitosis)
what happens in the zone of elongation in primary root growth
- most of the growing region of the root
- cell elongation pushes the root tip further down into soil
- 3 tissue systems begin to develop
what happens in the zone of differentiation in primary root growth
-aka zone of maturation
-cell differentiate into specific cell types occurs
whats the outmost primary meristem that will give rise to the epidermis?
the protoderm
ground tissue consists mostly of _ cells, found in the _, created via the _
parenchyma cells found in the cortex, created via the ground meristem
endodermis
- innermost layer of cortex
- a cyclinder 1 cell thick that is a selective barrier regulating movement of substances into the vascular stele
the _ gives rise to the vascular cyclinder (stele)
procambium
the _ is the innermost layer of cells right inside the endodermis. lateral roots arise from this.
pericycle
the shoot is derived from the SAM, which is protected by…
the leaves of the apical bud
shoot elongation is due to the lengthening of
the internodes
SAM gives rise to the to the same primary meristems as the root which are
- protoderm
- ground meristem
- procambium
in shoot development
branching arises from
axillary buds (each with their own apical meristem)
auxin prevents axillary buds from growing close to the apical meristem, what is this called
apical dominance
what do leaf primordia arise from, and what develops from the leaf primordia
the flanks of the shoot apical meristem.
leaves develop from the leaf primordia.
ground tissue consists of the tissues:
- parenchyma
- 1-2 layers collenchyma under epidermis
- some sclerenchyma fibres for support
explain the differences between eudicot vs dicot in the root and shoot cross sections.
- in eudicot roots the xylem is in a x shape, thin endodermis, no pith.
- In the monocot roots xylem is in a ring, thick endodermis, and pith is present.
- in eudicot shoots, vascular bundles are in a ring, pith is present (opp of eudicot roots)
- in monocot shoots vascular bundles are scattered and there is no pith.
what part of the leaf tissue does the protoderm give rise to
epidermis and a thick cuticle
