Easy
Multiple Choice
What is the process called where a zygote develops into an embryo?
A) Photosynthesis
B) Embryogenesis
C) Germination
D) Pollination
B) Embryogenesis
-defined as the process by which a single-celled zygote develops into an embryo.
In the 16-cell staged pro-embryo, which structure does the inner layer called the plerome eventually give rise to?
A) Cortex
B) Epidermis
C) Stele
D) Suspensor
C) Stele
-the inner cells differentiate into periblem and plerome. The periblem forms the cortex, while the plerome forms the stele.
Identification:
The embryonic precursor tissue layer produced during the 16-cell stage that undergoes anticlinal divisions to form the protective outer layer of the plant
Dermatogen
- The outer eight cells of the 16-cell globular embryo form the dermatogen, which differentiates exclusively into the epidermis.
True or False: The single-celled zygote undergoes a vertical division first to form a two-celled pro-embryo.
False
-undergoes a transverse division to form the two-celled pro-embryo.
Fill in the Blanks:
In a 2-celled pro-embryo, the larger cell positioned toward the micropylar end is known as the __________________ cell.
Basal cell
- The larger cell located towards the micropylar end is called the lower or basal cell.
Identification:
The specific structural region of an embryonic axis situated above the attachment point of the cotyledons, terminating at the plumule.
Epicotyl
- The epicotyl is the region of the embryo stem above the cotyledons that leads up to the plumule.
Multiple Choice
Which of the following correctly matches the embryo sheath with its corresponding protected embryonic part in a mature dicotyledon embryo?
A) Coleoptile covers root tip; Coleorhiza covers stem tip
B) Coleoptile covers stem tip; Coleorhiza covers root tip
C) Coleoptile covers cotyledon; Coleorhiza covers hypocotyl
D) Coleoptile covers hypocotyl; Coleorhiza covers plumule
B) Coleoptile covers stem tip; Coleorhiza covers root tip
-The coleoptile acts as the sheath covering the stem tip (plumule), and the coleorhiza acts as the sheath covering the root tip (radicle).
True of False:
The growth of the zygote into an embryo is triggered immediately after fertilization without waiting for any endosperm to form.
False
-The zygote remains in a short resting stage, and its growth is triggered only after a certain amount of endosperm is formed to ensure nutrition.
Identification
The fundamental cellular division pattern in which new cell walls are laid down perpendicular to the outer surface of the organ, thereby expanding the surface area of a tissue layer without adding cell depth.
Anticlinal division
-occur perpendicular to the outer surface, adding cells to the same single layer (such as the epidermis) rather than making new tissue layers.
Multiple Choice
Where does the embryo develop within the embryo sac?
A) At the micropylar end
B) At the chalazal end
C) At the center of the seed
D) Outside the ovule
A) At the micropylar end
The embryo develops at the micropylar end of the embryo sac, which is where the zygote is situated.
True or False:
The hypophysis divides during the heart-shaped embryo stage to form cells that contribute to the root cap and epidermis.
True
-During the heart-shaped stage, division of the hypophysis yields upper cells that form the root cap and epidermis.
Identification
The specialized single cell located at the junction between the suspensor and the embryonal mass that divides to contribute to root tissues.
Hypophysis
-The hypophysis is the uppermost cell of the suspensor adjacent to the embryonal mass, which divides to form the root cap and epidermis during later stages.
Multiple Choice
Which layer is formed when the outer eight cells (dermatogen) undergo anticlinal division?
A) Cortex
B) Stele
C) Epidermis
D) Endosperm
C) Epidermis
The outer eight cells (dermatogen) undergo anticlinal division to produce the epidermis layer.
True or False:
The plerome layer in the 16-cell staged embryo goes on to form the cortex of the plant.
False
The plerome forms the stele (vascular cylinder), while the periblem forms the cortex.
Identification
The single-celled diploid (2n) structure formed immediately after fertilization that serves as the starting point for embryogenesis.
Zygote
-The fertilized egg cell (2n) is the zygote, which remains in a brief resting stage before undergoing cell divisions to form the embryo.