Question
Question: Chalaza is- a. Ridge formed by the fusion of funicle within the body of ovule b. Space between i...
Chalaza is-
a. Ridge formed by the fusion of funicle within the body of ovule
b. Space between integument and nucellus
c. Place of origin of integuments
d. Place where nucellus communicates with the cavity of ovary
Solution
Among gymnosperms (e.g., conifers), the pollen is drawn into the ovule on a pinch of fluid that oozes out of the micropyle, known as the pollination drop mechanism. Subsequently, the micropyle shuts. Within angiosperms, only a pollen tube pierces the micropyle. During germination, the seedling's radicle appears through the micropyle near which the chalaza is located.
Complete answer:
In-plant ovules, the chalaza is situated opposite the micropyle releasing of the integuments. It is the tissue where the integuments and nucellus are linked. At the time of development of the embryo sac inside a flowering plant ovule, the three cells at the chalazal end turn into the antipodal cells.
A raphe (ridge) is created by the fusion of funiculus with the structure of the ovule. A gap occurs between the nucellus and integument towards the micropylar end known as Endosperm. Chalaza is the place where nucellus communes with the void of the ovary.
Located opposite from the micropyle is the chalaza where the nucellus is linked to the integuments. Nutrients from the plant move through the phloem of the vascular system to the funiculus and outer integument from there apoplastically and symplastically via chalaza to the nucleus inside the ovule. In chalazogamy plants, the pollen tubes go through the ovule through the chalaza instead of the micropyle opening.
For this reason, chalaza is the place of origin of integuments.
Hence, the correct answer is option (C).
Note: The crest formed by the fusion of funicle with the organization of ovule is called Raphe. The room between integument and nucellus is called endostome. Integuments initiate from the base of chalaza and end towards the micropyle where they coat the minute opening called the micropyle. The place where the nucellus corresponds with the cavity of the ovary is the Placenta.