Question

Hypostase is meant for providing
a. Support to embryo sac
b. Nourishment to embryo sac
c. Breaking continuity with parent
d. Pathway for growth of future embryo

Answer 1

Hint: The unusual feature which is present at the chalazal region of the embryo sac is called Hypostase. The nucellar cells are represented by hypostases through irregularly lined groups and poor cytoplasmic content. Van Tieghem introduces the name of hypostases. It is also referred to as a lignified tissue that forms the ovule base in certain orders of plants.

Complete answer:
The thickened cells which are found in the chalazal region of the ovules just below the embryo sac are called hypostases. The embryo sac receives the food from these cells and the secretion of hormones and enzymes also takes place. The accumulation of starch, proteins, and lipids are in the cells of hypostases. So, overall it provides nourishment to the embryo sac.
The embryo sac can support itself after proper maturation. It does not need any cells or medium for getting support.
Hypostase does not work for breaking the continuity with a parent that is why it is the wrong answer.
The pathway for the growth of the future embryo is called the embryonic pole.

Hence, the correct answer is option (B).

Additional information:
The main functions of Hypostase are:
- The transport of nutrition takes place by hypostases from chalaza.
- It helps to protect the seed.
- It helps to maintain the balance of water in the seed.
- The prevention of female gametophyte encroachment takes place by forming a barrier.

Note: So far we noted that hypostases are the type of cells present in the embryo sac. They do various functions in the embryo sac and protect it from the external environment. Hypostases are present in almost every plant embryo sac and serve the same function. The full embryo sac nourishment is the function of hypostases.