NEET BIOLOGY

Detailed explanation-1: -gymnosperm, any vascular plant that reproduces by means of an exposed seed, or ovule-unlike angiosperms, or flowering plants, whose seeds are enclosed by mature ovaries, or fruits. The seeds of many gymnosperms (literally, “naked seeds”) are borne in cones and are not visible until maturity.

Detailed explanation-2: -There are 4 major gymnosperm lineages on this planet-the Ginkgo, cycads, gnetophytes, and conifers. Each one of these groups contains members that produce fleshy structures around their seeds. However, their “fruits” do not all develop in the same way.

Detailed explanation-3: -In gymnosperms (plants with “naked seeds”-such as conifers, cycads, and ginkgo), the ovules are not enclosed in an ovary but lie exposed on leaflike structures, the megasporophylls.

Detailed explanation-4: -Most gymnosperms produce seeds in structures called cones or strobili (singular strobilus; Figure 8.1. 2). Cones evolved from modified leaves, and they can either be male cones that produce pollen, or female cones that produce ovules.

Detailed explanation-5: -The reproductive structures in gymnosperms are called cones or strobili. The strobili bearing microsporophylls and microsporangia are called microsporangiate or male strobili. The cones bearing megasporophylls with ovules or megasporangia are called macrosporangiate or female strobili.