Read the following statements and choose the correct ones.

I. Sepals and petals are non-essential floral organs in a flower.

II. The innermost wall layer of microsporangium is the tapetum. It nourishes the developing pollen grains.

III. In a dithecous anther, each lobe contains two microsporangia, resulting in a total of four microsporangia.

IV. The anther wall contains a middle layer located between the endothecium and tapetum.

I, II, III and IV

The correct answer is Option (4): I, II, III and IV

I. The statement is correct. Sepals and petals are considered non-essential floral organs in a flower. While they play important roles in attracting pollinators and protecting the reproductive parts of the flower, they are not directly involved in the reproductive process.

II. The statement is correct. A typical microsporangium appears near circular in outline. It is generally surrounded by four wall layers– the epidermis, endothecium, middle layers and the tapetum.  The innermost wall layer is the tapetum. It nourishes the developing pollen grains.

III. The statement is correct. A dithecous anther is composed of two lobes, and each lobe contains two microsporangia. Therefore, there are a total of four microsporangia in a dithecous anther, with two microsporangia present in each lobe.

IV. The statement is correct. Microsporangium appears near circular in outline. It is generally surrounded by four wall layers – the epidermis, endothecium, middle layers and the tapetum.The middle layer is located between the endothecium and the tapetum (the innermost layer). These layers serve various functions in the development and maturation of pollen grains within the anther.