POLARITY OF PLANT DEVELOPMENT Flashcards
plant dvevelopment diagram: (8)
1-cell
4-cell
octant
dermatogen
early globular
late globular
transition
late heart
Construction of the Arabidopsis Body Plan During Embryogenesis (8)
- Polarity Establishment
- Asymmetric Division
- Early Development
- Dermatogen Stage
- Globular Stage
- Heart Stage
- Torpedo Stage
- Quiescent Stage
Construction of the Arabidopsis Body Plan During Embryogenesis :
- Polarity Establishment
Post-fertilization, the Arabidopsis zygote exhibits polarity, characterized by a cytoplasmically dense _____ and more vacuoles at the _____.
- Asymmetric Division
the apical cell _____
the basal cell _____
- apical end
basal end - embryo
suspensor cells
Construction of the Arabidopsis Body Plan During Embryogenesis :
- Early Development
The embryo progresses through symmetric divisions forming a ____ structure of 2, 4, and 8 cells.
The suspensor continues to divide longitudinally. - Dermatogen Stage
Formation of the ____ (forms epidermis) from a single outer layer of cells through transverse divisions.
- radial
4.protoderm
Construction of the Arabidopsis Body Plan During Embryogenesis :
- Globular Stage
radial divisions give rise to ____ within embryo
lens shaped cell of the upper suspensor cell gives rise to ___ of the root apex
- Heart Stage
Proliferation of cells in the upper half gives rise to _____
- central vascular initials
central cells - cotyledon primordia
Construction of the Arabidopsis Body Plan During Embryogenesis :
- Torpedo Stage
torpedo stage embryo further elaboration of the root and shoot apices and growth of ____ - Quiescent Stage
embryo now has ____ cells and 0.5 mm in length
To activate it needs ___ and ___
- cotyledon
- 20,000 cells
dispersal
germination
Challenges of Embryogenesis (3)
- Body Plan Establishment
- Meristematic Tissue Reservation
- Food Reserve Establishment
Challenges of Embryogenesis:
- Body Plan Establishment:
Radial patterning produces ____
Axial patterning establishes the ____
- Tissue Reservation:
Setting aside ____ tissue for postembryonic growth (leaves, roots, flowers).
Food Reserve Establishment:
Creating accessible food reserves for the germinating embryo until it becomes _____.
- three tissue systems
apical-basal (shoot-root) axis. - meristematic
- autotrophic
Polarity Establishment:
Polarity in plants is established in the _____ The polarity of the embryo defines an axis upon which the body plan of the plant is elaborated
The ____ was shown to be a source of
position-dependent information required
for polarization in the Fucus zygote
first cell division post-fertilization
cell wall
Characteristics common to both angiosperm and brown algae:
Daughter cells stay connected after mitosis.
Cells are embedded in a rigid ____ made of cellulose fibrils.
Cells maintain cytoplasmic continuity through _____.
Both exhibit open growth strategies with continuous production of new organs from _____.
Some lineages have meristems capable of three-dimensional division, establishing secondary cytoplasmic continuity.
Multicellular development relies on ____ rather than clear cell lineages.
_____, the ability to dedifferentiate upon isolation, is common.
extracellular matrix
plasmodesmata
meristematic cells
positional control
Totipotency
Adult plant growth is due to the activity of _____ established during embryogenesis. Organised cellular structures capable of indeterminate growth contains an organised core of undifferentiated “____”
meristems
stem cells
Classification of meristem (3):
Origin
1. initial formative tissue from which other meristems are derived.
2. responsible for the primary growth of the plant.
3.Develops from permanent tissues
Location
1. tips of roots and shoots, responsible for lengthening the plant.
2.between mature tissues, often in grasses, aiding in regrowth of parts removed by grazing.
3. sides of stems and roots, responsible for thickening
Plane of Division
1. Cells divide in multiple planes.
2.Cells divide in two planes, like epidermal layers
3. Cells divide in one plane, leading to increased length of organs.
Origin
1. Promeristem
2. Primary meristem
3. Secondary meristem
Location:
1. Apical meristem
2. Intercalary meristem
3. Lateral meristem
Plane of Division:
1. Mass meristem
2. Plate meristem
3. Rib meristem
Planes of Cell Cleavage:
_____ are the ones that occur parallel to the tissue or organ surface resulting to rows of cells stacked one over the other “=”
______ is cleavage at right angles to the tissue or organ surface resulting to columns of cells adjacent to one another “ ||”
Periclinal cell divisions:
Anticlinal cell divisions:
DOMAINS OF GROWTH AND DEVELOPMENT
____ - straight line about which a body or a geometric figure rotates
_____establishes the apicalbasal (shoot-root) axis, embryonal axis divides the embryo or immature plant into regions by the help of embryonal
axis region.
____ are functional repetitive units of a plant, continually produced by root and shoot meristems throughout a plant’s vegetative life-cycle
Plant axis
Axial patterning
Phytomers
DOMAINS OF GROWTH AND DEVELOPMENT
(5)
(3)
Phytomer
Growth Unit
Axis
Architectural unit
Whole plant
Growth
Branching
Reiteration
Axial domain of growth:
_____- means forming the center
_____- means away from the center
_____ - facing away from the axis of an organism
_____ - facing toward the axis of an organism
Central
Peripheral
Abaxial
Adaxial
Axial domain of growth:
___ = _____
= _____
saggital plane
coronal plane
The ____ is essential for radial growth. Thickening of vascular plants is regulated by stem cell-like tissues, including the vascular and the _____ organized in concentric cylinders
vascular cambium
cork cambium
Radial growth (5)
vascular cambium cell
new secondary xylem cell
new secondary phloem cell
new secondary xylem cell
new secondary phloem cell
Maturity and polarity:
acropetal growth had greater _______ (i.e., mitotic activity) near the tip and a gradient of maturation toward the base
cell proliferation
EMBRYONIC CELL FATE
Cell fate determination is governed by (2)
(1) its parent cell (i.e. the cell’s lineage)
(2) the position of the cell within the embryo
____ regulates cell fate by influencing gene expression through its signaling pathways. It interacts with_____and other signaling molecules to turn genes on or off, leading to the activation or repression of growth factors and developmental genes.
The unique transport mechanism of auxin, involving _____ that direct its movement from cell to cell, creates the gradients that are so essential for its signaling role.
Auxin
transcription factors
efflux carriers
The apical cell and its daughters adopt an isometric growth pattern and divide twice longitudinally and once transversely to form a spherical ____ of eight cells.
The uppermost daughter of the basal cell, termed ____, eventually becomes part of the primary root meristem, whereas the remaining daughters form the extraembryonic suspensor.
proembryo
hypophysis
Development of Embryonic Shoot / (Shoot Apical Meristem (SAM) Organization)
Zones of the SAM (3):
This is the topmost region of the SAM, where cells are primarily undifferentiated and are actively dividing responsible for maintaining the stem cell population.
Surrounding the prior, cells start to differentiate and contribute to the formation of new organs such as leaves.
Located beneath , the rib zone contributes cells to the stem and internodes as the plant grows vertically.
Central Zone (CZ)
Peripheral zone (PZ)
Rib Zone (RZ)
