Question

Circinotropous ovule occurs in
a. Opuntia
b. Ranunculus
c. Polygonum
d. Cicer

Answer 1

In a cinotrocirpous ovule, the length of the funiculus becomes increased and it covers the whole ovule.

Complete Answer:
Ovule is part of the female reproductive organ in seed plants. It comprises the nucellus, the integuments that form the outermost layer, and the female gametophyte. According to the shape, the ovule has been categorized into six types.
- Option a: Opuntia has a Circinotropous ovule. In this type of ovule, the length of the funiculus increases and covers the whole ovule. Therefore, this option is correct.
- Option b: Ranunculus has a hemi anatropous ovule in which the body of the ovule is turned through 90°. The micropyle and chalaza lie in a straight line but the funiculus is at 90° to both micropyle and chalaza. Therefore, this option is incorrect.
- Option c: Polygonum has an orthotropous ovule. In this type of ovule, micropyle, chalaza, and funiculus lie in a straight line. Therefore, this option is incorrect.
- Option d: Cicer has an anatropous ovule in which the body of the ovule is rotated by 180° and the micropyle comes near to funiculus. Chalaza and Micropyle are in a straight line but the hilum is at 90° to the micropyle. Therefore, this option is incorrect.

Note: The most common form of the ovule in Angiosperm is anatropous ovule. In this type of ovule, the ovule is inverted and the micropyle is bent down to the funiculus.