Monera

There are millions of organisms on the earth.

These organisms were classified by R.H. Whittaker into five kingdoms based on their cell structure, body organization, mode of nutrition, etc.

All the prokaryotic organisms are included in the kingdom Monera.

Prokaryotic organisms include all the organisms that do not have a nucleus i.e. the bacteria.

These organisms are made of just 1 cell (single-celled) and all the life processes are carried out by the same single cell.

General structural features of the members of Monera:

The outermost layer of most of the prokaryotic cells is a slimy (sticky) polysaccharide layer called the capsule or glycocalyx.

Just under the capsule layer, the cell wall is present. While the capsule is present in some bacteria, the cell wall is present in almost all the bacteria.

Some bacteria lack a cell wall and these bacteria are placed in the group Mycoplasma.

The cell wall is made of either peptidoglycan or a combination of peptidoglycan and lipopolysaccharides.

A delicate plasma membrane or cell membrane lies just below the cell wall.

The plasma membrane forms the boundary for the gel-like cytoplasm.

The cytoplasm in these organisms does not contain membrane-bound (not covered with a membrane) cell organelles.

The cytoplasm includes DNA, ribosomes (70S), and inclusion bodies.

Since they have no membrane-bound nucleus, their genetic material or DNA lies naked in the cytoplasm.

This naked DNA of bacteria is called the nucleoid.

Mode of nutrition in the members of Monera:

The members of the kingdom Monera are autotrophic or heterotrophic.

The autotrophic monera members like all other autotrophic organisms make their own food.

However, the source of energy they use for making their food may differ. While some use sunlight, others derive energy from chemicals.

On the other hand, the heterotrophic members depend on other organisms or dead and decaying matter for their food.

Locomotion in the members of Monera:

The organs of locomotion in these organisms are long filamentous appendages known as flagella.

Apart from flagella, some bacteria have pili with the help of which they attach to surfaces.

The members of Monera reproduce both sexually and asexually.

Asexual reproduction in these organisms occurs mainly by binary fission.

Some bacteria reproduce asexually by forming spores or by budding.

Sexual reproduction is rare and does not involve the fusion of gametes.

Instead, sexual reproduction involves the exchange of genetic material between a donor cell and a recipient cell.

This exchange of genetic material can occur by one of these 3 processes: Transformation, Transduction or Conjugation

Revision

Kingdom Monera includes unicellular prokaryotic organisms that lack a nucleus and membrane-bound cell organelles.

They are autotrophic or heterotrophic.

Locomotion in these organisms occurs with the help of flagella.

They reproduce by both sexual and asexual reproduction.

The End