NEET BIOLOGY

Detailed explanation-1: -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-2: -In gymnosperms, a leafy green sporophyte generates cones containing male and female gametophytes; female cones are bigger than male cones and are located higher up in the tree. A male cone contains microsporophylls where male gametophytes ( pollen ) are produced and are later carried by wind to female gametophytes.

Detailed explanation-3: -In most gymnosperms the male pollen cones, called microstrobili, contain reduced leaves called microsporophylls. Microsporangia, or pollen sacs, are borne on the lower surfaces of the microsporophylls. The number of microsporangia may vary from two in many conifers to hundreds in some cycads.

Detailed explanation-4: -The seed is the embryonic stage of the plant life cycle. Most seeds consist of three parts: embryo, endosperm, and seed coat. The embryo is a tiny plant that has a root, a stem, and one or more leaves. The endosperm is the nutritive tissue of the seed, often a combination of starch, oil, and protein.