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The gymnosperms were the first seed plants and bore their ovules and seeds exposed on the plant surface. This is in marked contrast to the more recent seed plants, the flowering plants, which have their ovules sealed within the flower and their seeds contained within a fruit. The name gymnosperm describes this feature. It means naked seed.Â
The life cycle of a gymnosperm begins on a mature sporophyte plant. Male spores grow into male gametophytes inside male cones. Today I will get a brief description of the gymnosperms and the difference between gymnosperms and angiosperms.
Examples of Gymnosperm
Here are the main 4 examples of gymnosperms mentioned below.
- Conifers
In the Pinophyta or Coniferophyta, Conifers are the most numerous gymnosperms; woody and vascular tissue are cone-bearing trees and shrubs.
Conifers can be found growing in all parts of the world, although they most notably dominate the boreal forests of the northern hemisphere. Many are adapted to cold climatic conditions, with downward-facing branches, which help shed snow, and specific biochemical properties resisting freezing.
Examples of conifers include pines, yews, redwoods, spruces, firs and cedars.
The conifer forests of the world cover huge land areas and provide the largest terrestrial carbon sink. Conifers are also valued economically; their softwood is used for the production of paper and timber, they are used to cultivate pine nuts, and the berries of the juniper bush are used to flavour gin.
- Cycads
The appearance of the cycads (division Cycadophyta) typically constitutes a single, stout, cylindrical, woody trunk and a crown of large, hard and stiff, evergreen compound leaves, which grow directly from the trunk in a rosette formation. The cycads are dioecious, meaning that each plant is either all male or all female.
The cycads are partly xerophyte, which means they are adapted to survive in areas with very little liquid water. However, their distribution largely centres around the subtropical Tropic of Cancer and the Tropic of Capricorn and tropical regions such as Central and South America, China and Southeast Asia, India and Sri Lanka, Madagascar, and Tropical and Southern Africa. The cycads were much more numerous in the past than today, peaking in ‘the age of the cycads’ – the Jurassic period. There are only three extant families within the cycads today: the Cycadaceae, Stangeriaceae, and Zamiaceae.
- Gnetophytes
The Gnetophyta are distinguishable within the gymnosperms because they have vessel elements, a system of channels mostly found in the angiosperms, which transport water within the plant.
Covering 70 species over three genera, the Gnetophyta are morphologically variable, including trees, shrubs, stumps, vines, and creepers with leaf shapes ranging from opposite to whorled, scale-like straplike.
- Gingko
The closest relatives to the cycads, Gingko is a genus of gymnosperm of which Ginkgo Biloba is the only extant species.
Ginkgos are large, slender, shade-intolerant trees, growing up to 160ft with distinctive fan-shaped leaves. They are deep-rooted and resistant to damage from wind and snow. They are also resistant to disease and insect damage due to an exceptionally large genome, enabling antibacterial and chemical defence mechanisms.
Gingko first appears within the fossil record in the Permian period, 270 million years ago, and the Ginkgo Biloba remains largely unchanged today, earning it a classification as a ‘living fossil.’
The above examples of gymnosperms give you an idea of how they are.
What is the difference between gymnosperms and angiosperms
Following are the important differences between angiosperms and gymnosperms:
| Angiosperms | Gymnosperms |
| Sepals and petals are present in angiosperms. | Sepals and petals are Absent in gymnosperms. |
| The sporophyll bears the small thalamus in angiosperms. | The sporophyll bears an elongated central axis in gymnosperms. |
| Double fertilisation occurs when both male gametes are in an active state. One plays a role in reproductive fertilisation and the other for vegetative fertilisation or triple fusion in angiosperms. | In contrast, only one type of fertilisation occurs in gymnosperms, and only one gamete is functional. |
| Eggs are present inside the ovary’s ovary; These are attached to the placenta, and they (ovarian) are produced on a stalk or fungus in angiosperms. | In gymnosperms, ovules lie on megasporophylls and are not borne on the placenta, and they (ovules) are sessile. |
| Megasporophylls are structured to form a carpel; microsporophylls are represented by a stamen, which includes the stamen and filament in angiosperms | while gymnosperms have a woody part, and abroad, a sterile head represents microsporophylls. |
| Angiosperms are also the source of the world’s hardwoods. Flowering plants are economically important as they serve as a source of pharmaceuticals, lumber, ornaments, fibre products, and other commercial uses. | At the same time, gymnosperms provide pine, cedar, and softwoods for making paper, lumber, and plywood. Are known to have taken. |
| Stigma and style are present in angiosperms, and four microsporangia or pollen sacs are usually present. | Stigma and style are absent in gymnosperms, and microsporangia range from two (Pinus) to several hundred in Cycas. |
Conclusion
Gymnosperms are an ancient group of plants that include familiar living forms such as conifers, cycads, and ginkgos and many far less well-known and long-extinct kinds.Â
Gymnosperms represent a broad range of seed-bearing plants that differ from flowering plants in not having seeds enclosed within carpels. Gymnosperms are a good source of food. Seeds of these plants are widely used to produce many food products. Gymnosperms are vascular plants that produce pollen grain and seeds. Ovules contain egg-producing female gametophytes. Gymnosperms were the most dominant species in the Mesozoic era.
