Gymnosperm

In botany, a category of plants known as Gymnosperms are defined as “plants that develop seeds that are not encased within the ovary or fruit.”

Gymnosperms are a type of flowering plant.

Gymnosperm is derived from the Greek terms “gymnos” (naked) and “sperma” (seed), and as a result, they are also known as “Naked seeds.” Gymnosperms are seed-producing plants, but they differ from angiosperms in that they do not produce fruits in addition to seeds. These plants generate a cone-like structure on the surface of scales or leaves, or at the ends of stalks, depending on the environment.

Gymnosperms are plants in which the ovules are not encased within the ovary wall, in contrast to angiosperms. Gymnosperms are plants that produce seeds. During and after fertilisation as well as before turning into a seed, the embryo stays exposed. Gymnosperm stems can be either branched or unbranched, depending on the species. The thick cuticle, needle-like leaves, and recessed stomata of these plants all work together to minimise the rate of water loss.

Gymnosperms are a group of plants that includes conifers, cycads, gnetophytes, and the species of Ginkgophyta division and Ginkgo biloba, among other things.

Gymnosperm characteristics are as follows:

Gymnosperms are distinguished by the following important characteristics:

1)They don’t produce any flowers at all.

2)Seeds are not generated within the walls of a fruit. They are completely undressed.

3)In colder climates, where snowfall is common, they can be found.

4)They produce needle-like leaves as a result of their growth.

5)They are either perennial or woody, and they can grow into trees or bushes.

6)Their ovaries, style, and stigma are not distinguishable from one another.

7)Because they do not have a stigma, they are pollinated directly by the wind.

8)However, only one of the gametes that are produced by the male gametophytes is functional.

They grow into cones that contain reproductive elements.

9)The seeds include endosperm, which serves as a food storage organ for the plant’s growth and development.

10)These plants have vascular tissues, which aid in the transfer of nutrients and water throughout the plant’s structure.

11)The absence of vessels in the xylem and the absence of companion cells and sieve tubes in the phloem are indicative of the absence of vessels.

12)Gymnosperms are classified according to their flowering time.

Gymnosperms can be divided into four types, which are listed below: –

Cycadophyta

Cycads are dioecious, which means they reproduce in twos (meaning: individual plants are either all male or female). Cycads are flowering plants that produce seeds, however the majority of their species have gone extinct. It was during the Jurassic and late Triassic periods when they had reached their zenith. Nowadays, the plants are regarded as historical treasures that should be preserved.

This type of plant has enormous compound leaves, thick trunks, and little leaflets that are all linked to a single central stem, which is characteristic of this type of plant. They can grow to be many metres in height, or as small as a few centimetres in height.

Cycads are most commonly found in the tropics and subtropics of the world. Some individuals have acclimated to dry, arid settings, while others have adapted to marshy, low-oxygen habitats, among other things.

Ginkgophyta

Another Gymnosperm class, the Ginkgophyta, includes only one extant species, which is a genus of Gymnosperms. All other members of this class have died out, and there are no more of them.

The Ginkgo trees are distinguished by their huge size and fan-shaped leaves, which give them their name. In addition, Ginkgo trees have a wide range of uses, spanning from medicine to cooking and everything in between. Ginkgo leaves are taken internally as a treatment for memory-related diseases such as Alzheimer’s disease.

Ginkgo trees are also extremely resistant to pollution, as well as disease and insect infestations, making them an excellent choice for urban landscaping. As a matter of fact, they are so hardy that after the atomic bombs landed on Hiroshima, six Ginkgo trees were the only living beings to survive within a kilometre or two of the blast zone.

Gnetophyta

Gnetophytes, like any other member of the gymnosperm family, are relics from a bygone era of evolution. Currently, only three representatives of this genus are known to exist.

Gnetophytes are plants that grow in tropical climates such as trees and bushes. They are distinguished by the presence of floral leaves with a velvety coating. The presence of this covering shows a common ancestor with the angiosperms.

Because they have vessel elements in their xylem, gnetophytes are distinguished from the other members of this class.

Coniferophyta

These are the gymnosperm species that are the most well-known among the general public. Because they are evergreen, they do not lose their leaves over the cold months. These are primarily distinguished by the presence of male and female cones, which combine to produce needle-like structures.

Coniferous trees are typically found in temperate climates with average temperatures of 10 degrees Celsius. Conifers include giant sequoias, pines, cedars, and redwoods, to name a few examples.

Gymnosperms are a type of flowering plant.

Gymnosperms are found in a variety of habitats, including:

Cycas \Pinus \Araucaria

Thuja \Cedrus

Picea \Abies

Juniperus \larix

Gymnosperms have a life cycle that is similar to ours.

Gymnosperms reproduce through the alternation of generations during their life cycle, which includes both haploid and diploid reproduction. They reproduce through a sporophyte-dominant cycle.

In comparison to other phases of development, the gametophyte phase is rather brief. The reproductive organs are often shaped like cones.

Male cones are characterised by the presence of microsporophylls that contain microsporangia. Microsporangium is a haploid microspore producing plant. Only a few microspores develop into male gametes, which are known as pollen grains, while the majority of microspores degenerate.

Feminine Cones– The megasporophylls generate female cones when they come together in a group. They are endowed with ovules that contain megasporangium. It is capable of producing haploid megaspores as well as a megaspore mother cell.

The pollen is carried to the egg by the wind or by any other pollination agent, and the pollen grain releases a sperm when it contacts the egg. A zygote is formed when the nuclei of both male and female gametophytes fuse together. Fertilisation is the term used to describe this process.

The Most Important Facts About Gymnosperms

Gymnosperms are non-flowering plants that are members of the sub-kingdom Embryophyta, which means “embryophyte.”

In contrast to an ovary or a fruit, seeds are not encapsulated within them. Gymnosperms have leaf-like structures on the surface of their leaves, which allows them to be seen.

The Coniferophyta, Cycadophyta, Ginkgophyta, and Gnetophyta are the four main classifications.

Boreal and temperate woods both contain Gymnosperms as well as other conifers.

CONCLUSION:-

The spermatophytes, sometimes known as seed plants, are made up of gymnosperms and angiosperms together. Gymnosperms are classified into six phyla, or groups of plants. Organisms belonging to the phylum Cycadophyta, Ginkgophyta, Gnetophyta, and Pinophyta (also known as Coniferophyta) are still alive, whereas organisms belonging to the phyla Pteridospermales and Cordaitales are no longer alive.