Difference Between Monera and Protista

Key Difference – Monera vs Protista
 

Monera and Protista are two kingdoms of living organisms that represent the unicellular organisms though there exists a difference between them based on the cell structure and organization. All living organisms are classified into five kingdoms based on their complexity of the cell structure, body organization, modes of nutrition, lifestyle, and phylogenetic relationship. Monera and Protista represent the most primarily build unicellular organisms, while Fungi, Plantae, and Animalia include the most complex multicellular organisms. The main difference between Monera and Protista is that Monera has a unicellular prokaryotic cellular organization which lack membrane-bounded organelles whereas Protista has a unicellular eukaryotic cellular organization with membrane-bounded organelles.

What is Monera?

Kingdom Monera consists of all the prokaryotes, which include bacteria, blue-green algae, and cyanobacteria. The unicellular, microscopic prokaryotes often live in moist conditions. Some of them live as solitary organisms while some live in colonies. The colonial species can be found as filaments or short chains. Since they are prokaryotes, they lack an organized, membrane-bounded nucleus, but only a circular DNA molecule. Moreover, these organisms lack membrane-bounded organelles, unlike the eukaryotes. Some of their cells are enclosed by a cell wall. All the organisms can be either autotrophic (synthesize their own food) or heterotrophic (cannot synthesize their own food). These organisms only show asexual reproduction by means of  binary fission or budding. The organisms of the Kingdom Monera has two groups; Archaebacteria and Eubacteria.

Difference Between Monera and Protista

Figure 1: Cyanobacterium

What is Protista?

Kingdom Protista includes unicellular organism but with the eukaryotic cellular organization, which contains membrane-bounded organelles such as nucleus, mitochondria, Golgi bodies, etc. Protiests are primarily aquatic. Some of these organisms have special structures like cilia and flagella that are used in locomotion. The mode of nutrition of protists can be photosynthetic, holozoic or parasitic. A group of protists called phytoplankton are the primary producers of oceans. Phytoplankton has cell made up of cellulose and is able to photosynthesize. Some protists are predatory and lack cell walls (e.g., protozoans). Protists act as an evolutionary link between the prokaryotic monera and multicellular organisms. Kingdom Protista includes the diatoms, protozoans, and unicellular algae.

Key Difference Between Monera and Protista

Figure 2: General structure of a protist.

What is the difference between Monera and Protista?

Characteristics of Monera and Protista

Cell Structure

Monera: a Monera has a unicellular prokaryotic cellular organization which lack membrane-bounded organelles.

Protista: Protista has a unicellular eukaryotic cellular organization with membrane-bounded organelles.

Presence of Flagella and Cilia

Monera:  Flagella and Cilia are usually not found in Monera.

Protista: Some organisms have these structures for locomotion.

Mode of Nutrition

Monera: Mode of nutrition is either autotrophic (synthesize their own food) or heterotrophic (cannot synthesize their own food)

Protists: Mode of nutrition is photosynthetic, holozoic or parasitic

Mode of Reproduction

Monera: The mode of reproduction is asexual  by means of fission or budding

Protists: The mode of reproduction can be asexual (binary fission or multiple fission) or sexual

Groups of Organisms

Monera: bacteria, blue-green algae, and cyanobacteria

Protista: diatoms, protozoans, and unicellular algae

 
Image Courtesy:
“Cyanobacterium-inline ro” by Kelvinsong (CC BY 3.0 )via Wikimedia Commons
“Euglena diagram” by Claudio Miklos – Simple English Wikipedia. (CC0) via Wikimedia Commons