Examkin

Question

Difficulty: MediumSpermatophytes: Gymnosperms and Angiosperms

A botanical researcher isolates megasporophylls from a mature female cone of a coniferous plant. Which structural feature of the ovules on these cone scales confirms that the plant is a gymnosperm rather than an angiosperm?

  1. They develop directly on the exposed surfaces of the scales without being enclosed within an ovary wallAnswer
  2. B
    They are completely enclosed within a carpel that later develops into a protective fruit pericarp
  3. C
    They undergo double fertilization to form a triploid endosperm nutritive tissue for the embryo
  4. D
    They receive water and organic nutrients through bidirectional translocation in specialized phloem vessels

Answer

The ovules develop directly on the exposed surfaces of megasporophylls without being enclosed within an ovary wall.
The defining diagnostic feature of gymnosperms is that their ovules are borne un-enclosed on the surface of megasporophylls (cone scales). Because there is no surrounding ovary wall, true fruits are not formed, resulting in 'naked' seeds.

Step-by-Step Solution

1
Identify the key anatomical definition of gymnosperms.
Gymnosperm translates literally to 'naked seed', meaning ovules and seeds are not enclosed inside an ovary.
Taxonomic classification relies on reproductive organ structure.
2
Compare gymnosperm ovule placement with angiosperm ovule placement.
Angiosperm ovules are enclosed within carpels (ovaries), whereas gymnosperm ovules sit directly exposed on cone scales (megasporophylls).
This structural difference determines whether true fruits are formed.

Key Concept

Structural differences between gymnosperm and angiosperm seed protection and ovule placement
Rate this question

Topics

Spermatophytes: Gymnosperms and Angiosperms

More questions from this topic