The broad kingdom of Plantae consists of over 2 million different species. These organisms are all non-motile, eukaryotic, multi-cellular, and autotrophic. Their cells contain chlorophyll that helps in photosynthesis. They have various cell organelles for photosynthesis, reproduction, and support.
Classification of Plant Kingdom
All of the million species under Kingdom Plantae are classified into five subgroups based on their features, such as their plant body’s complexity, presence or absence of a vascular system, and how they bear seeds. These five subgroups are thallophytes, gymnosperms, angiosperms, bryophytes, and pteridophytes.
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Thallophyta:
They are primitive in terms of body structure and are called ‘thallus,’ meaning body structure is not well differentiated. They are mostly aquatic (marine or freshwater) or are found in moist habitats. A few examples of Thallophytes are Green algae like Volvox, Spirogyra, and brown algae like Fucus,
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Bryophyta:
They are a little more complex in terms of body structure when compared with Thallophytes since they have root-like, stem-like and leaf-like structures. They are also terrestrial plants dependent on water for reproduction. It explains why they are called “Amphibians of the Plant kingdom” and why they are mostly seen in moist, shady places. Examples of Bryophytes include Marchantia, Funaria, and Sphagnum.
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Pteridophyta:
The plants in this subgroup develop distinctly into the root, stems, and leaves. They are terrestrial and have a vascular system within the body, which helps conduct water and minerals to different body structures. They reproduce by dispersing spores and do not produce seeds. Selaginella and Pteris are some common examples.
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Gymnosperms:
These are further developed plants that are capable of bearing naked seeds. They are fully terrestrial with differentiated body structures. They also have a developed vascular system to supply water and minerals to all these body structures. Pinus, Cycas, and Ephedra are Gymnosperms plants.
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Angiosperms:
They are the most advanced plants with well-differentiated plant bodies, developed vascular systems, and bear seeds covered within fruits. The significant difference between bryophytes pteridophytes gymnosperms and angiosperms is the seed-bearing capacity. These include plants like Eucalyptus, rose, mango, etc.
Differentiation Between Bryophytes and Pteridophytes
There are several similarities between bryophytes and pteridophytes. The alternation of generation in bryophytes and pteridophytes are similar in both. To sum up, the significant difference between Bryophyta and Pteridophyta subgroups is tabulated below.
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Bryophytes |
Pteridophytes |
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They have a thallus, leafy body. |
Pteridophytes differ from bryophytes in having well-differentiated body structures such as roots, stems, and leaves. |
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They do not have vascular structures within the body. |
They have well-developed vascular tissues to supply water and minerals to body parts. |
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They have primitive rhizoid structures to anchor to the ground. |
Roots anchor the plant body to the ground. |
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They have two types of rhizoids. |
They have only one kind of rhizoid. |
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The predominant body in the life cycle is the gametophyte for bryophytes. |
The predominant body in the life cycle is the sporophyte for pteridophytes. |
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The sporophyte is dependent on the gametophyte. |
The sporophyte phase and gametophyte stages are both independent and autotrophic, which distinguishes between Bryophyta and Pteridophyta. |
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They are homosporous. |
They may be homosporous or heterosporous. |
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They have a stalked antheridium. |
The antheridium is attached to the base (sessile) and reduced. |
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They have haploid cells. |
They have diploid cells. |
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Their sporophytes are not well-differentiated beyond the root, set, and capsule. |
The sporophyte is well-differentiated into the root, stems, and leaves. |
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Their gametophytes may be leafy or thalloid. |
Their gametophytes are always thalloid. |
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They are terrestrial but dependent on water for reproduction. |
They are completely terrestrial and can reproduce in the absence of water. |
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Examples: Mosses and Liverworts |
Examples: Ferns and Spikemosses. |
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Bryophyte Life Cycle
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Pteridophyte Life cycle
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Fun Facts
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Researchers at the University of Exeter discovered that bryophytes might have caused an ice age during the Late Ordovician Mass Extinction. As they spread across the land, they altered the bedrock composition, sucked in all the air’s carbon dioxide, and brought the temperature down.
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Bryophytes can absorb water from the air and pass it on to leaves. Since they do not have a vascular system, they do not extract water from the soil through roots like other plants.
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Fern species (Pteridophytes) can come in all sizes ranging from 3 inches to even 30 feet tall.
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Ferns take up nitrogen from the air, and hence farmers sometimes use ferns as natural fertilizers in rice fields.
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In ancient cultures, mosses were used to cleanse and heal wounds. When allied surgeons ran out of cotton on battlefields during World War I, they began to use moss as a temporary stopgap on wounds.