Question

Compare the gymno and angio endosperm.

Answer 1

The endosperm in angiosperms is formed through double fertilization and is the main nutritive tissue for the developing embryo. In contrast, gymnosperms do not have an endosperm, and their nutritive tissue comes from the female gametophyte. Angiosperms exhibit variation in how the endosperm is utilized and stored, with differences seen between monocots and dicots.

Step-by-step explanation:

Comparison of Gymnosperm and Angiosperm Endosperm

The endosperm is a nutritive tissue that provides food for the developing embryo in seed plants. In angiosperms, or flowering plants, the endosperm is formed as a result of a unique process called double fertilization. During this event, one sperm cell fertilizes the egg to create a diploid zygote, while another sperm cell fuses with the polar nuclei to produce a triploid endosperm.

This endosperm is the main source of nutrients for the embryo as it develops within the seed. In contrast, gymnosperms, such as conifers, do not have an endosperm. Instead, their nutritive tissue is part of the female gametophyte that directly nourishes the developing embryo.

Furthermore, the storage and utilization of the endosperm can vary among angiosperms. In monocots, like corn and wheat, the food reserves are stored in a large endosperm, which is utilized upon germination to support the growing embryo.

On the other hand, some dicots may transfer these reserves to the cotyledons, reducing the endosperm as the seed matures. The endosperm in dicots that retain it is referred to as 'endospermic dicot'. Regardless of the specific storage strategy, angiosperm seeds typically begin development with an endosperm that serves as a nutritional resource.

Answer 2

Gymnosperm seeds lack an endosperm, relying on female gametophytes for nutrition, while angiosperms have a triploid endosperm formed by double fertilization that provides nourishment to the embryo.

Step-by-step explanation:

The comparison of gymnosperm and angiosperm endosperm revolves around the presence and function of nutritious tissue in seeds. Gymnosperm seeds do not have an endosperm; instead, their female gametophytes serve as the food reserve for the developing embryo. In contrast, angiosperms have a unique feature of double fertilization, where one sperm fuses with the egg to create a diploid zygote, and another sperm fuses with polar nuclei to form a triploid endosperm.

This endosperm is the main nutritive tissue for the growing embryo in angiosperms. In some angiosperms, the endosperm persists in the seed and provides food to the germinating embryo, while in others, it is absorbed during seed development, and the embryo relies on its cotyledons for nutrition.

Monocots and dicots both possess endosperms with varying roles. For instance, in monocots like corn, the substantial endosperm stores food, which the scutellum, the single cotyledon, absorbs and transfers to the embryo during germination.

In many dicots, the endosperm may get consumed as the cotyledons develop, leaving little endosperm. Thus, the key distinction between angiosperm and gymnosperm endosperm is that the former is an outcome of double fertilization and acts as the key nutritive source for the embryo, while the latter is non-existent.