CBSE Class 10 Answered

The typical anther is bilocular, i.e. it consists of two thecae. Each theca contains two microsporangia, also known as pollen sacs. The microsporangia produce the microspores, which for seed plants are known as pollen grains.

If the pollen sacs are not adjacent, or if they open separately, then no thecae are formed. In Lauraceae, for example, the pollen sacs are spaced apart and open independently. The outer cells of the theca form the epidermis. Below the epidermis, the somatic cells form the tapetum. These support the development of microspores into mature pollen grains.