Plant Growth And Development Flashcards
Plants Double fertilization
1) binding of the egg and sperm cells (syngamy) resulting in the zygote and
2) the addition of the sperm to the bi-nucleate central cell of ovule.
Syngamy
binding of the egg and sperm cells
Where is the single called zygote formed
In the ovule within the carpel.
Explain the first cell division
Results in two cells, basal and apical. Show expression of WOX2 and WOX8/9 genes.
The gene family responsible for these divisions of cells in zygote are
WUSCHEL related homeobox (WOX)
second division stage resulting in ____ cells
4
What genes are shown in second division stage
WOX2 and WOX8/9 genes
How does apical cell divide in second division stage
vertically producing two side-by-side cells
How does basal cell divides during the second division
horizontally producing one cell on top of the other
Third division stage results in ___ cells
8
How does third division stage works
the two apical cells divide horizontally resulting in an
apical domain, under the control of the WOX 2 gene
and a central domain, under the control of WOX 9 gene
the basal cells continue to divide horizontally resulting in a
hypophysis cell controlled by WOX8/WOX9 genes
and a suspensor controlled by the WOX8 gene
WOX genes also establish _______ and __________ of __________ transport between cells in the developing embryo.
Production, directionality of auxin (growth hormone)
At the very first cell division, the ______ cell produces auxin that is then transported to the _____ cell (one-way!).
Basal, apical
8-16 cell division is called
the globular stage
following the division from the 8 to 16-cell division (referred to as the globular stage), cells in the ______ produce auxin that is then transported to the _______ cells
Apical domain, central domain.
After the globular cell division, auxin transport becomes more complicated with auxin production in the center of the _______ and the _____
apical domain and the hypophysis
Structure of auxin transportation resembles the shape of
A heart
Further cell division is completed with a characteristic embryo developed with three major regions:
epicotyl
cotyledon
radicle
Epicotyl
dominated by the shoot meristem derived from the center of the apical domain line of cells
Cotylédon
derived from remaining apical domain cell lines
Radicle
including cells of the central domain and hypophysis which will become the stem/root
plant seed is generally composed of four parts:
1) embryo, 2) cotyledon, 3) endosperm, and 4) seed coat.
cotyledon (in embryo)
often referred to as a “leaf.”
a specialized storage unit that is utilized by the seed following germination and seedling emergence
in flowering plants two groups are found, one with a single cotyledon (monocot) and one with two cotyledons (dicot)
monocots are considered to have evolved from early angiosperms, particularly aquatic plants like water lilies
Endosperm
energy compound rich material (starch, oils) used for rapid growth following germination
