Plants with Seeds – Gymnosperms and Angiosperms with their Differences

The Five Kingdom Classification Model looks at five divisions of organisms. One of the divisions is Kingdom Plantae. These organisms are mostly multicellular and eukaryotes. They use chlorophyll for photosynthesis thus are autotrophs.

There might be some exceptions in every feature. This kingdom includes five divisions – Thallophytes, Bryophytes, Pteridophytes, Gymnosperms, and Angiosperms.

There are different features and functions of these organisms which differentiates the division in kingdom Plantae on the basis of criteria like plant body, vascular system, and seed formation.

The first three divisions of kingdom Plantae don’t have seeds and the last two do. This is the major difference between them to look at largely. The Gymnosperms and Angiosperms consist of seeds and may bear flowers and fruits. They have a well-defined structure with roots, stem, and leaves.

They also possess a well functioning vascular system for transportation in the plants. These further have subgroups further based on different features again. We will look at the last two divisions of the Plant Kingdom. Let’s look at Gymnosperms and Angiosperms in detail:

Phanerogams – Plants with Seeds

Plants that have reproductive tissues end up producing seeds, they are phanerogams. The reproduction process leads to the formation of seeds. They have embryos with food for the process of germination. The phonograms are further classified in angiosperms and gymnosperms based on seed covering.

Angiosperms

The angiosperms are part of the kingdom Plantae and make up 80% of the plant population on the earth. They are the most commonly found plants because they can grow in various habitats in the ecosystem.

They are flowering plants and can bear fruit as well. The seed lives in the plant organs. Let’s look at some of the important characteristics of Angiosperms –

Characteristics of Angiosperms

• They all grow flowers at some or the other stages of their life cycle. This is because flowers are the reproductive organ of these plants and facilitate genetic information as well.
• They have a well-defined structure with stem, roots, and leaves.
• They also possess a vascular system with xylem and phloem.
• Their reproductive organs – stamens and pistils are inside the flower.
• There are four microsporangia in each microsporophyll.
• They are heterosporous and produce microspore and megaspores.
• These organisms are diploid in nature.
• The roots have complex structures with cortex, xylem, phloem, and epidermis.
• The flowers can have fusion 2-3 times and form a diploid zygote and triploid endosperm.
• Their female reproductive organs are small in size thus the fertilization process is faster.
  Pollen Grains of Stamens carry hereditary information. The reproduction process is by pollination.
• They produce endosperm which feeds the seed and seedlings.
• The developing seeds can turn into a flower or directly into a fruit.
• Some examples of angiosperms are Cactus, Rose, Daisy, Etc.

Classification of Angiosperms

There are two types of angiosperms. Let’s look at them –

Monocotyledons

• The seeds of monocotyledons have one cotyledon only.
• They have simple leaves and parallel veins.
• They have adventitious roots.
• Also, they have closed transportation bundles in the vascular system in large numbers.
• Some examples are banana, sugarcane, etc.

Dicotyledons

• The seeds of dicotyledons have two cotyledons.
• They have reticulate venation leaves.
• They have tap roots.
• The vascular system has organized bundle rings.
• Some examples are grapes, sunflowers, etc.

Gymnosperms

They are again seed-producing in nature but produce seeds without fruits. They develop on the surface of leaves and form a cone-like shape and are around 390 million old.

Their ovules are not closed inside the ovary wall. They are exposed before and after the process of fertilization. Some of the examples of gymnosperms are – pines, spruces, etc.

Characteristics of Gymnosperms

• They don’t bear flowers or fruits at any point of time.
• The seeds remain naked and not inside the fruit. This is because they don’t have ovaries.
• They are mainly located in colder areas with snowfall seasons.
• Their leaves develop a needle-like structure.
• They live for several years and thus form bushes.
• They don’t have a division for ovary, style and stigma. The pollination is directly by the wind.
• They produce only one functional gamete.
• The seeds of these plants have endosperms to store food for the future.
• They have a developed vascular system for the transportation of nutrients and water.

Classification of Gymnosperms

There are four types of Gymnosperms. Let’s take a look at them –

Cycadophyta
Cycads are dioecious which means their male and female organs are in different plants. They are mostly extinct now and were prominent during Jurassic. They have large compound leaves mostly. With thick trunks and small leaflets connected to a single central stem.

They have an average height between centimeters to meters. They are usually located in tropical and subtropical areas. Though some of them adopt dry arid and swampy environments with time.

Ginkgophyta
All the plants under this type of gymnosperms are extinct except one species. These plants are large in size and have fan-like leaves. They also have many uses ranging from medicinal to cooking. They can survive in pollution and act as a remedy for severe diseases like Alzheimer’s.

An interesting fact to know about these trees is that they survived the nuclear bombs in Japan.

Gnetophyta
They are again extinct now and act as relics. Only three of its species exist today. They are usually tropical plants, trees and shrubs and have flowery leaves with a soft coating. They are different from other divisions because they have vessel elements in their xylem.

Coniferophyta
They are the most common gymnosperms. They are evergreen in nature and don’t shed any leaves. These have male and female cones that create needle-like structures. These trees are mainly located in average temperature areas. Some examples are pines, cedar and redwood.

Gymnosperms Life Cycle

They follow a reproduction process by the alternation of generations. The sporophytes are dominant in this cycle. They are both haploid and diploid. The life phase of a gametophyte is very short and the cones act as reproductive organs.

The male cones have microsporophylls that produce haploid microspores and few of them develop into pollen grains. The female cones are of megasporophylls and produce haploid megaspores.

The pollination is by wind where the pollen grain releases sperm and fuses with female gametophyte to create a zygote. This process is called fertilization.

Conclusion

The Angiosperms and the Gymnosperms bear seeds and have few similarities. This is because gymnosperms are 200 million years older than angiosperms. Thus they evolved over time to create angiosperms. The main difference comes from their diversity which is greater in gymnosperms. This article will guide you on their features, structure, classification, characteristics, and uses with examples.

There are details for each subhead mentioned before with light on all features. The UPSC Prelims may have a question from this topic as it comes under basic science. Other competitive exams like RRB, SSC, Banking and more will also have an interest in this to check the candidate’s general knowledge. All the UPSC Aspirants must go through this article once to understand basic science topics.