Question

What are the characteristics of Pine due to which it is not placed on the sub division angiosperm ?​

Answer 1

Explanation:

The angiosperms, or flowering plants, are the largest and most species-rich phylum of plants, with more than 250,000 species estimated.

Defining Characteristics

The term "angiosperm" derives from two Greek words: angeion, meaning "vessel," and sperma, meaning "seed." The angiosperms are those plants whose seeds develop within a surrounding layer of plant tissue, called the carpel, with seeds attached around the margins. This arrangement is easily seen by slicing into a tomato, for example. Collectively, carpels together with the style and stigma are termed the ovary, and these plus associated structures develop into the mature

Answer 2

Answer:

The term "angiosperm" derives from two Greek words: angeion, meaning "vessel," and sperma, meaning "seed." The angiosperms are those plants whose seeds develop within a surrounding layer of plant tissue, called the carpel, with seeds attached around the margins. This arrangement is easily seen by slicing into a tomato, for example. Collectively, carpels together with the style and stigma are termed the ovary, and these plus associated structures develop into the mature fruit. The enclosed seeds and the presence of carpels distinguish angiosperms from their closest living relatives, the gymnosperms , in which the seed is not enclosed within a fruit, but rather sits exposed to the environment. Some defining characteristics of angiosperms include flowers, carpels, and the presence of endosperm, a nutritive substance found in seeds, produced via a second fertilization event. However, some current studies suggest that endosperm is not unique to angiosperms.

Angiosperm flowers are generically characterized by having four whorls, or sets of organs: sepals , petals, stamens, and carpels. The carpels may be united or fused to form a compound pistil , and the number of stigma lobes may then be indicative of the number of carpels. The pistil also includes the stigma, on which pollen lands, and style, the tube leading to the egg. Stamens are separated into anthers, which produce pollen, and filaments. The mature ovary (part of the pistil containing the seeds) is termed a "fruit." Sepals and petals may be showy and colorful to attract pollinators, or may be quite reduced in wind-pollinated plants, such as grasses. Likewise, fruits may assume a wide variety of forms associated with mode of dispersal, such as fleshy fruits (for example, berries) dispersed by animals, and dry, winged fruits adapted for wind dispersal, such as the samaras of maple trees, which twirl like helicopters as they fall.

Explanation: