Question
Question: The suspensor during the development of an angiosperm embryo is formed from A) Basal cell B) Api...
The suspensor during the development of an angiosperm embryo is formed from
A) Basal cell
B) Apical cell
C) Embryonal cell
D) Generative cell
Solution
Early in embryogenesis, the suspensor provides the developing embryo with physical support, nutrients and growth regulators.The suspensor is derived from the basal cell formed after asymmetric zygote division in most plants.
Complete answer:
Morphogenetic gradients formed prior to zygote division can result in cellular differences between the suspensor and the embryo proper. In comparison to the embryo proper, the suspensor grows quickly and becomes the first distinct embryonic structure developed during seed production. The suspensor is later programmed to die and is no longer present in mature seeds.
Suspenders are available in a variety of shapes and sizes. They may be single-celled or multicellular, small or large in comparison to the early embryo, and filamentous, columnar, circular, or irregular in shape. A few exceptional genera tend to be devoid of any kind of organised suspensor. In some animals, the line between the embryo proper and the suspensor is well defined, while in others it is more ambiguous.
Suspensor cells also have structural variations that aren't present in the embryo itself. Suspensor cells may be polytene, polyploid, or multinucleate, among other things. A few suspensor develop elaborate outgrowths (haustoria) that invade the endosperm or maternal tissues around them.
In angiosperms, the diploid zygote divides mitotically to produce an embryo.In the early stages of development, the embryo divides transversely to form a two-cell proembryo with the upper terminal cell and the lower basal cell. The basal cell divides many times to form the suspensor, a multicellular structure, while the terminal cell divides many times to form the embryo proper.
The correct answer is option (A) Basal cell.
Note: In plants, suspensor are found in angiosperm zygotes, connecting the endosperm to the embryo.Suspensor cells in dicots divide transversely several times to create a filamentous suspensor with 6-10 cells. The suspensor is analogous to the umbilical cord of the placental mammal.