Botany - Plant Kingdom Question with Solution | TestHub
Which of the following pairs of organisms are correctly matched with their description?
Pteridophytes which are heterosporous: Selaginella, Salvinia
Gymnosperms with branched stem: Pinus, Cedrus
Algae with haplo-diplontic life cycle: Ectocarpus, Polysiphonia
Bryophytes with protonema stage: Polytrichum, Sphagnum
Options:
Answer:
Solution:
In majority of the pteridophytes all the spores are of similar kinds; such plants are called homosporous. Genera like Selaginella and Salvinia which produce two kinds of spores, macro (large) and micro (small) spores, are known as heterosporous. The stems of gymnosperms are unbranched (Cycas) or branched (Pinus, Cedrus). The predominant stage of the life cycle of a moss is the gametophyte which consists of two stages. The first stage is the protonema stage, which develops directly from a spore. It is a creeping, green, branched and frequently filamentous stage. The second stage is the leafy stage, which develops from the secondary protonema as a lateral bud. Common examples of mosses are Funaria, Polytrichum and Sphagnum. While most algal genera are haplontic, some of them such as Ectocarpus, Polysiphonia, kelps are haplo-diplontic. Fucus, an alga is diplontic.
