Angiosperm

Angiosperms belong to one of the most diverse and largest extant flora in the universe. Angiosperms have about 453 families, including about 260,000  classified species. In addition, about 80% of all known green plants on Earth are represented by angiosperms (Manjunatha et al., 2019). It is very well known that vascular seed plants, where the egg fertilizes and grows into seeds in a closed hollow ovary, are angiosperms.

The seeds of angiosperms, unlike gymnosperms, such as conifers and cinnabars, are found in flowers. In gymnosperms, the seeds are produced in contact with the stem and surface of the reproductive organs, such as the cones. Furthermore, both male and female organs can be easily found in the flowers of angiosperms. 

 Angiosperms occupy almost every habitat on earth, except those that support extreme climatic conditions such as the highest mountain ranges,  deepest blue oceans, and existing and poles surrounding areas. They can be found as epiphytes (living on many other plants), floating on surface waters, rooted in freshwater and marine habitats, and terrestrial plants of various sizes. 

Angiosperms can be thought of as small herbs, parasites, vines, and giant trees, ranging from small millimeters like small floating plants to large trees over 100 meters high. Of note here is the tremendous variety in angiosperm chemistry, reproductive cycle, morphology, anatomy, and size compared to other members and species of the plant kingdom.

Definition 

Angiosperms are a taxonomic class of flowering trees. When these trees mature, they produce seeds wrapped in eggs (usually fruits). For example, apples are mature seeds produced by angiosperms. Apples are ovaries or egg cells. Angiosperms lose their leaves in the fall and re-grow in the spring to become deciduous trees. They are classified as hardwoods and include species such as oak, maple, and honeybee.

Angiosperm Anatomy and Morphological Features

Concerning the definition and background of angiosperms detailed above, many scientists describe them as “flowering” plants and classify them into a single phylum:  Anthophyta. Their floral anatomical parts include pollen, stamens, and/or carpels.

The sperm of flowering plants are pollen grains produced by the stamens. Pollen grains contain male gametes and can react with female gametes (ovary) in plant ovaries. These gametes allow angiosperms to reproduce sexually. (Note: Angiosperms can reproduce certain forms of asexual reproduction, such as vegetative propagation and apomixis, in addition to sexual reproduction.)

Since the pollen grains of angiosperms are smaller than the pollen of gymnosperms, reducing the size allows the female eggs to be reached in a shorter period, facilitating the fertilization steps. It is common for some families of angiosperms to breed without fertilization, or in other scenarios, they can be fertilized themselves by using their pollen. Therefore, stamens play a very important role in the fertilization cycle of flowering plants.

The next very important part of the angiosperm anatomy is the structure in which both male and female reproductive parts of angiosperms can be found. Flowers are designed to attract insects and other mammals to the allogeneic pollination process. In a variety of plants, the flowers have a colorful and pleasant scent. The ovary behind the 

 Plant flower is surrounded by carpel. Angiosperms absorb pollen and can begin producing seeds, flowers, and fruits faster than gymnosperms. If we can carefully observe the entire development process of the plant, we can conclude that the fruit develops from the pollinated flowers and that the carpel is mainly involved in this.

Angiosperms, despite their diversity, are united by common features and have a common origin known as synapomorphies. Some important features of angiosperms are that the ovule is present in the carpel which is a structure made up of the ovary and the ovules enclosed in it and pollination takes place here. Second, a  double fertilization cycle occurs leading to the formation of endosperm and three stamens including a few pollen sacs. Finally,  angiosperms have phloem tissues mainly consisting of sieve tubes and companion cells. Therefore, it can be concluded that the levels of angiosperms come from many different origins rather than just one.

Difference between Angiosperm and Gymnosperm 

Angiosperms and gymnosperms are the two main groups of vascular seed plants. Angiosperms, which are flowering plants, are the largest and most diverse group in the kingdom Plantae. With around 300,000 species, they represent about 80% of all known green plants living today. Gymnosperms are a very small and older group, and it includes plants that produce “conifers” (seeds that are not protected by fruit). There are more than 1,000 species of gymnosperms still found on Earth.

Many ecological niches are occupied only by angiosperms. For example, carnivorous plants,  aquatic plants, and parasitic plants (with one possible exception) are all flowering plants. In addition, the majority of the plants that humans consume as food are angiosperms, but the seeds of some gymnosperms, such as ginkgo and pine nuts, are regionally important in some particular areas.

Conclusion 

Angiosperms, also known as flowering plants, are one of about 300,000 species of flowering plants, the largest and most diverse group in the kingdom Plantae. Angiosperms make up about 80% of all living green plants known today. Angiosperms are vascular seed plants in which an ovum (egg) is fertilized and develops into a seed in an angiosperm. The ovary itself is usually enclosed in a flower, the part of an angiosperm that contains male or female reproductive organs, or both. The fruit is derived from the mature floral organs of angiosperms and is thus characteristic of angiosperms. In contrast, in gymnosperms (e.g., conifers and cycads), the other major group of plants with vascular seeds, the seeds do not develop encased in an ovary but are normally produced exposed on the surface of the plants. And Reproductive structures, such as cones.