Plants are one of the creatures that are essential for the sustenance of life as they have the ability to convert sunlight and inorganic compounds into food and energy.
Angiosperms and gymnosperms are the two major groups of seed-bearing vascular plants that have the natural ability to produce seeds and are surrounded by nutritive tissue and coated with a seed coat.
The main difference between these two species is diversity. Angiosperms are flowering plants and are the largest and most diverse group within the Kingdom Plantae with more than 300,000 species that represent approximately 80% of all the green plants living whereas gymnosperms are smaller and more ancient groups with less than 1000 species found on Earth.
|Seed||Seeds develop in the ovaries of flowers and are surrounded by a protective fruit||Seeds are produced by non-flowering plants and are unclosed or naked|
|Reproductive Structures||Flowers are the reproductive organs and they can be both uni-sexual or bisexual||In gymnosperms the reproductive structure are cones which are generally uni-sexual|
|Spores||Microspores are produced in anthers while the megaspores are produced in ovules of the ovary in flowers||Both the microspores and megaspores are produces by male and female cones|
|Leaves||Leaves are flat in shape||In gymnosperms, leaves are scale-like and needle-like in shape|
|Mode of Pollination||Angiosperms rely on bees, bird, as well as on other abiotic factors such as wind and water for pollination||Gymnosperms solely rely on the wind to carry pollen between male and female reproductive parts|
|Tissue Type||It has triploid tissue||It has haploid tissue|
|Life cycle||The life cycle of Angiosperms are seasonal||These plants are evergreen|
|Example||Grass, Bamboo, Coconut tree, etc.||Pinus, Cycas, Cedrus tree, etc.|
What are Angiosperms?
Around 200 – 250 million years ago, angiosperms were evolved and today they are the largest and diverse group in Kingdom Plantae.
Angiosperms can be defined as flowering or vascular plants with seeds, fruits, and flowers for reproduction and are found in almost every habitat from grasslands and forests to sear margins and deserts.
Angiosperms can be seen in a variety of forms around us such as herbs, shrubs, trees, bulbs, submerged aquatics, and epiphytes. The pleasing and attractive colours of these flowering plants certainly add much more life and colour wherever they are present.
Features of Angiosperms
The important and diverse characteristics of angiosperms are mentioned below:
- In angiosperms, flowers are the reproductive organs providing them with a means of exchanging genetic information.
- The sporophyte is differentiated into stems, roots, and leaves.
- The vascular system has true vessels in the xylem and companion cells in the phloem.
- The stamens (microsporophyll) and the carpels (megasporophyll) are organized into a structure called the flower.
- One megasporophyll (stamen) contains four pollen sacs (microsporangia).
- The ovules are enclosed in the ovary at the base of the megasporophyll.
- Angiosperms are heterosporous, i.e., produce two kinds of spores, microspore (pollen grains) and megaspores.
- A single functional megaspore is permanently retained within the nucleus.
- The pollen grains transfer from the anther to stigma and reproduction takes place by pollination and is also responsible for the transfer of genetic information from one flower to the other.
- The sporophytes are diploid.
- The root system is very complex and consists of cortex, xylem, phloem, and epidermis.
- The flowers undergo double and triple fusion which leads to the formation of a diploid zygote and triploid endosperm.
- Angiosperms can survive in a variety of habitats, including marine habitats.
- The process of fertilization is quicker in angiosperms. The seeds are also produced quickly due to the smaller female reproductive parts.
- All angiosperms are comprised of stamens which are the reproductive structures of the flowers.
- The carpels enclose developing seeds that may turn into a fruit.
- The production of the endosperm is one of the greatest advantages of angiosperms. The endosperm is formed after fertilization and is a source of food for the developing seed and seedling.
Why is Angiosperm Important to Humans?
Angiosperms are important to human in many ways such as,
- Plants such as grasses (rice, corn, wheat, oats, sugar cane, etc.), the rose family (apples, pears, cherries, etc.), potatoes, tomatoes, peppers, coconuts, and olives are a central component of human nutrition and the human economy.
- Angiosperms are also the source of paper for writing, fiber for clothes, wood for furniture, and a variety of medicines.
What are Gymnosperms?
The word Gymnosperm is derived from the Greek word “gymnospermos” meaning naked seed.
Unlike angiosperms, the seeds of gymnosperms are exposed and are borne in cones until maturity and do not produce flower or fruit.
Gymnosperms are often found in boreal forest biomes and temperate forests.
Types of Gymnosperms
Ginkgo is often referred to as a “living fossil” can live for thousands of years and are characterized by fan-shaped, deciduous leaves that turn yellow in autumn.
Cycads are found in the tropical forests and subtropical regions. These evergreen plants have a feather-like leaf structure and long stems that spread the large leaves out over the thick, woody trunk.
One of the greatest variety of species among gymnosperms. Most conifers are evergreen (retain their leaves throughout the year) and include some of the largest, tallest and oldest trees on the planet.
Examples of conifers include pines, sequoias, firs, hemlock, and spruces. Conifers are an important economic source of lumber and products, such as paper, that is developed from wood.
Gnetum species contain some shrubs and trees, but most are woody vines that climb around other plants. They are found in the tropical rain forest and have broad, flat leaves that resemble the leaves of flowering plants.
- The key difference between angiosperms and gymnosperms is how their seeds are developed. The seeds of angiosperms are developed in the ovaries of flowers and are surrounded by fruit while the seeds of gymnosperms are naked that lacked fruits and flowers.
- Angiosperms can be seen in a variety of forms ranging from annual herbs to massive trees while gymnosperms are large shrubs and woody trees.
- Angiosperms contain conducting tissues called “vessels” while gymnosperms do not contain.
Around 200 million years ago gymnosperms were identified as small plants that produce naked seeds but today angiosperms are identified as the largest and most diverse group in the Plant Kingdom that produces seeds within the ovary of a flower.