Question

In Xenia, pollen affects the _______
A. Endosperm
B. Testa
C. Tegmen
D. Nucellus

Answer 1

Hint: In a fertilized plant, the effect of pollen on seeds and the fruits is called the xenia effect. It is different from the effect of pollen during pollination. Wilhelm Olbers Focke was the botanist who coined this term in 1881.

Complete answer:
Wilhelm Olbers Focke referred to the term “Xenia” for the effects of pollens on the maternal tissues, seed coat and pericarp. Endosperm was also considered related to maternal tissue and thus the term xenia is also associated with the pollen effects on endosperm.

So the correct answer is A) Endosperm.

Additional information:
The developing embryo depends on endosperm for nutrition as it is the main source of food for the developing embryo. It is formed by the process of triple fusion in which one of the male gametes fuses with the secondary diploid nucleus. Thus the endosperm formed is triploid in angiosperms. The nucleus of the endosperm in most cases, divides after the division of the oospore but in several cases, the endosperm is almost completely formed even before the first division of oospore.
Every seed has an outer covering called the seed coat. It develops from the integuments of the ovule. The outer coat is called teat and the inner layer is called tegmen. If only one covering is present in the seed, it is called testa. Testa is hard and leathery while tegmen is thin and membranous.
A nucellus is a part of an ovule. It is the central body of the tissue of the ovule.

Note: Xenia effect caused due to the genetic difference between two strains of maize has been observed and it has increased the grain yield in the plant. It also helps to grow male-sterile plants that are preferred over genetically modified crops.