Question

which of the following statements is correct?
A) Horsetails are gymnosperm.
B) Ovules are not enclosed by the ovary wall in gymnosperms.
C) Stems are usually unbranched in both cycas and Cedrus
D) Selaginella is heterosporous, while Salvinia is homosporous

Answer 1

Hint:Gymnosperm which is also referred to as Acro Gymnospermae is a group of flowerless plants that produce seeds and cones.

Complete answer:
The term gymnosperm literally translates to naked seed as they are flowerless. This is due to the fact that the seeds in gymnosperms are not encapsulated within the ovaries. Instead, they are exposed on the surface of leaf-like structures where they sit and they are called blacks. Gymnosperm is a group of vascular plants belonging to Embryophyta which is a sub-Kingdom and it includes a wide variety such as cycads, gnetophytes, conifers, and ginkgoes. There are other recognizable examples of these trees and shrubs which include spruces, pines, ginkgoes, and first. These classes of gymnosperm are rapidly available in biomass such as temperate forests and boreal forest the species live in moist or dry weather conditions. As mentioned earlier, gymnosperm does not contain the ability to produce any fruit or flowers which is unlike angiosperm. According to biologists, gymnosperms are believed to be the very first vascular plants. They started to appear and innovate the land in the traffic period which is estimated to be around 208 to 245 million years ago.
Vascular plants include the horsetails, Ferns, gymnosperms, and angiosperms. Horsetails are seedless vascular plants that reproduce with spores and are found in a moist environment. In angiosperm, ovules are enclosed by the ovary. In gymnosperm, ovules are not enclosed by an ovary wall. In cycas the stem is erect, stout, and unbranched. However, in pinus and Cedrus the stem is branched selaginella and Salvinia are heterosporous. They have spores of two different sizes, microspores, and megaspores.
Thus, the answer is option B: Ovules are not enclosed by the ovary wall in gymnosperms.

Note: Most of the conifers are evergreen, which means that they hold their leaves all throughout the different seasons in the year. They include a fraction of the largest and oldest trees on the earth.