Plantae Kingdom - Classification of Living Beings

Kingdom Plantae - Classification of living beings

We can find various types of living beings in the environment. These vary in size from microscopic to giant structures. They do have different structures of cells, body structures, and other different characteristics. Based on that, Robert Harding Whittaker classified living beings into 5 kingdoms. They are listed below.

5 Kingdoms of Biosphere

1. Monera,
2. Fungi,
3. Protista,
4. Plantae, and
5. Animalia

Among these five kingdoms, here we will discuss Plantae Kingdom.

Plantae Kingdom

In the Plantae kingdom, plants are classified into three major divisions. They are algae, bryophyta, and tracheophyta.

1. Algae

Observation

Observe the following pictures and identify their characteristics.

We cannot distinguish the root, stem, and leaves of the plants shown above. The body of these plants is called a thallus. These plants contain cell walls and chlorophyll in their cell. They fall under the division Algae.

Characteristics of Algae:

Following are the characteristics of Algae

1. These plants can be unicellular as well as multicellular.
2. They contain chlorophyll and collect food as starch.
3. The cell wall is made up of cellulose.
4. They undergo sexual or asexual reproduction.
5. These kinds of plants are usually found in moist areas, ponds, or rivers.

Examples: Volvox, Spirogyra, Fucus.

2. Bryophyta

Observation

Observe the following pictures and identify their characteristics.

Bryophyta is well developed than algae. Marchantia has a thallus body, whereas moss has a less developed stem and leaves. They are green plants. They are amphibian plants, as water is needed for reproduction. They are also found in moist places.

Characteristics of Bryophyta

The following are the characteristics of Bryophyta:

1. Bryophyta are multicellular plants.
2. Bryophyta are autotrophs.
3. Bodies of some Bryophyta are thallus, some are rhizoid and some are simple leaves.
4. Bryophyta is found in moist and cold places.
5. These plants do not have vascular tissue. So, they cannot grow tall and are only a few cm tall.
6. Male and Female plants are different during the gametophyte condition. Male plants produce male gamete on antheridium and female plants produce female gamete on archegonium. The female gamete is also known as the ovum. Male gamet using water reaches to female gamet and mates to form a zygote which later forms into a sporophyte condition.
7. The cycle of gametophytic and sporophytic processes in the life cycle of moss is also known as the alternation of generation. In the life cycle, gametophytic generation is long, dominant, and independent.

Examples: Marchantia, Moss, Riccia

3. Tracheophyta

Those plants which have distinct, root, stem and leaves fall under this classification. Different types of trees, from small to large trees fall into this division. They include both flowering and nonflowering plants. There are three subdivisions under Tracheophyta. They are:

• Pteridophyta
• Gymnosperm
• Angiosperm

Pteridophyta

Observation

Observe the following pictures and identify their characteristics

Ferns are found in moist and shady places. They bear spores, which fall on the ground to form gametes and reproduce. They have feather-like leaves.

Characteristics of Ferns

The following are the characteristics of Ferns:

1. These plants are found in moist and shadowed places.
2. They do not have seeds but they have distinct root, stem, and leaves.
3. They have feather-like leaves, less-developed stems, and well-developed roots.
4. They have developed vascular tissues such as the xylem and phloem.
5. These plants contain many sori behind their leaves. They produce spores. Some of the plants do not produce spores. Those who produce spores are sporophytes and those who don’t produce spores are called tropophiles. These are also called sporophytes.
6. Spores, when they fall on the ground germinate to form a gametophyte named prothallus. Gametophytes produce both male and female gamete for sexual reproduction.
7. Alteration of generation occurs in the lifecycle of these plants, where the sporophytic process is long and dominant.

Examples – Fern, Ground Gooseberry, Tetris, etc.

Gymnosperm

Trees like Pine, fir, and cycas have cones instead of flowers and do not bear fruit but they have naked seeds. These trees are classified into sub-division gymnosperms.

Characteristics of Gymnosperms

1. Gymnosperms are the first plants that produced seeds.
2. These plants have cones instead of flowers. These are unisexual and the male cone differs from the female cone. Pollination occurs by the medium of air.
3. The cones do not contain ovaries. Hence they do not bear fruits and have naked seeds.
4. They have narrow, long, and needle-like leaves.
5. The Stem of these plants is covered by thick barks.
6. These are called coniferous plants as most of the plants are cone-shaped.
7. The roots are spread in wide areas.

Examples – Pine, Fir, Cycas, Himalayan Cedar, etc.

Angiosperm

Angiosperm are those plants that bear flowers as well as fruits and the seeds are covered inside the fruit.

Characteristics of Angiosperms:

1. These are the most developed plants of Kingdom Plantae.
2. These are aquatic as well as terrestrial.
3. They have well-developed roots, stems, leaves fruits, and seeds.
4. They bear real flowers and the flowers contain ovules and ovaries.
5. Some of the Angiosperm are unisexual whereas some are bisexual.
6. Pollination occurs by the medium of air, water, or insects.
7. Seeds of angiosperms are covered by the fruits.

Examples – Orange Tree, Banana Tree, Paddy Tree, Pistia, etc.

Angiosperms are further divided into two classes based on cotyledons inside their seeds.

They are:

A. Monocotyledons