Question

Which Pteridophyta bears cones?
A. Lycopsida and Psilopsida
B. Filicinae and Lycopsida
C. Filicinae and Sphenopsida
D. Lycopsida and Sphenopsida

Answer 1

Hint: Pteridophyta is a seedless vascular plant that is found in cool, damp, and shady places. Their main plant body is a sporophyte which is differentiated in true roots stem and leaves. The sporophyte bears sporangia that are subtended by leaf-like appendages called sporophylls. In some cases, sporophylls may form distinct compact structures called cones.

Complete answer: Pteridophyta is divided into 4 classes:-
1. Psilopsida - The most ancient vascular plants are placed in this class. Their plant body is differentiated into stem, scaly leaves, and rhizoids. Example - Rhynia.
2. Lycopsida - Club mosses are placed in this class. The plant body is differentiated into roots, stems, and leaves. Sporophylls are present in groups and at the tip of the plant. This group structure is called strobilus or cone.
3. Sphenopsida - This class includes Horsetails. The plant body is differentiated into roots, stems and shady leaves. The formation of sporangia takes place on special branches of the stem called sporangiospores. Sporangiospores are arranged in a group and form a long condensed cone. This cone is formed at the apical part. Example - Equisetum.
4. Pteropsida- It is the largest group of Pteridophytes, commonly known as ferns. Every leaf of a fern forms sporangia at the time of reproduction. Therefore cones are not produced in ferns.
Thus, option D is the correct answer.

Note: In some pteridophytes, sporangia are not formed at the lower surface of the sporophylls, instead they are formed in sporocarp. Sporocarp is a multicellular structure on which spore-producing structures are formed.