Question

Which one of the following represents an ovule, where the embryo sac becomes horseshoe shaped and the funiculus and micropyle are close to each other?

• A. Circinotropous
• B. Anatropous
• C. Amphitropous
• D. Atropous

Answer 1

The Correct Option is C

To determine which type of ovule is being described, we need to understand the structural orientation of an ovule that results in a horseshoe-shaped embryo sac with the funiculus and micropyle close to each other. Let's go through the options systematically:

1. Circinotropous: In this type of ovule, the funiculus is very long, allowing the ovule to turn completely around, making about 360 degrees of rotation. However, the embryo sac does not become horseshoe-shaped, which rules out this option.
2. Anatropous: This is the most common type of ovule, where the body of the ovule is completely inverted, and the micropyle is near the hilum. The embryo sac is not typically horseshoe-shaped in anatropous ovules, eliminating this choice.
3. Amphitropous: In an amphitropous ovule, the nucellus is curved in such a way that the embryo sac forms a horseshoe shape. Additionally, in these ovules, the funiculus and micropyle are positioned closer together due to the curvature. This description matches the question precisely, making this the correct answer.
4. Atropous: These are orthotropous ovules that have a straight configuration, with no curvature leading to a horseshoe-shaped embryo sac. Hence, this option does not fit the given description.

The correct answer is Amphitropous because these ovules exhibit a distinctive horseshoe-shaped embryo sac, and the curvature brings the funiculus and micropyle closer.