Module: | Pre-fertilization: Micro/Megasporogenesis
Q35: Consider the following statements regarding the spatial orientation of ovules:
1. The anatropous ovule is the most common type in angiosperms, characterized by a completely inverted body.
2. In an anatropous ovule, the micropyle points downward and lies in close proximity to the hilum.
3. In an orthotropous (straight) ovule, the micropyle, chalaza, and funicle fail to align in a straight vertical line.
Which of the above statements is/are correct?
2. In an anatropous ovule, the micropyle points downward and lies in close proximity to the hilum.
3. In an orthotropous (straight) ovule, the micropyle, chalaza, and funicle fail to align in a straight vertical line.
Which of the above statements is/are correct?
✅ Correct Answer: A
The correct option is A. Statements 1 and 2 are correct, but Statement 3 is incorrect.
The spatial orientation of the ovule body relative to its stalk (funicle) is a fundamental taxonomic feature in botany.
Found in over 80 percent of angiosperm families, the anatropous ovule is structurally inverted.
The causal growth mechanism involves the unequal expansion of the funicle during development, which bends the ovule 180 degrees.
This inversion brings the micropyle (the pollen tube entry pore) downward, locating it right next to the hilum (the attachment scar). Conversely, the orthotropous ovule is the primitive, upright form.
Statement 3 is incorrect because the defining characteristic of an orthotropous ovule is that the micropyle at the top, the chalaza in the middle, and the funicle at the base all lie in one perfectly straight, unbroken vertical line (e.g., in Polygonum).
The spatial orientation of the ovule body relative to its stalk (funicle) is a fundamental taxonomic feature in botany.
Found in over 80 percent of angiosperm families, the anatropous ovule is structurally inverted.
The causal growth mechanism involves the unequal expansion of the funicle during development, which bends the ovule 180 degrees.
This inversion brings the micropyle (the pollen tube entry pore) downward, locating it right next to the hilum (the attachment scar). Conversely, the orthotropous ovule is the primitive, upright form.
Statement 3 is incorrect because the defining characteristic of an orthotropous ovule is that the micropyle at the top, the chalaza in the middle, and the funicle at the base all lie in one perfectly straight, unbroken vertical line (e.g., in Polygonum).