Tag: monera

Prokaryotes are unicellular organisms. They lack membrane-bound organelles like mitochondria, golgi apparatus. They also lack true nucleus. Instead, they have nucleoid or incipient nucleus. Nucleoid is an undifferetiated, unorganised, fibrillar nucleus without any limiting membrane. They have ribosomes in the cytoplasm. Examples include bacteria like E. coli, blue green algae. 

Moneran are prokaryotic unicellular organisms. They lack membrane-bound organelles. They lack true nucleus. They have genetic material without nuclear envelope. The examples of Moneran include bacteria, blue green algae like Nostoc, Spirulina, Oscillatoria. Euglena is an eukaryotic organism

Prokaryotes are placed in a group Monera. These includes bacteria, Cyanobacteria, Eubacteria, etc. They are unicellular organisms. They have cell wall. They lack membrane-bound organelles like mitochondria. They also lack true nucleus. Instead, they have nucleoid, a genetic material without nuclear envelope.

• Bacteria having rod-shaped structure are called as Bacilli. Examples include Clostridium tetani, Corynebacterium.
• Bacteria having spiral shape are called as Spirilla. Examples include Spirillum, Campylobacter.
• Bacteria having a comma-like single curve in their body are Vibrio. Examples include Vibrio cholerae, Vibrio vulnificus.
• Bacteria that are round in shape are called as cocci. Examples include Streptococcus pneumoniae, Staphylococcus aureus. 

Whittaker's classification includes five kingdom classification system. The five kingdoms include Monera, Protista, Fungi, Plantae, and Animalia. Monera includes Eubacteria and Archeobacteria. They include non-nucleated unicellular organisms. They are prokaryotes. They have a cell wall. They have no membrane-bound organelles and true nucleus.

Prokaryotes are all single-celled organisms eg, Mycoplasmas, bacteria, cyanobacteria. So, the correct option is C.(Mycoplasmas, bacteria, cyanobacteria)

The cell wall is a rigid layer that gives shape to the bacterial cell. It also protects the bacteria from the external environment.

Cyanobacteria (Blue-green algae or BGA) sometimes reproduce exponentially to form blooms. Blooming cyanobacteria can secrete death factors in such concentrations that they poison and even kill animals and humans. It can also accumulate in other animals such as fish and shellfish and cause poisonings such as shellfish poisoning.

Most bacteria are heterotrophic, however, a special class of bacteria called cyanobacteria or BGA are autotrophic, that is they can produce there own food. So, the correct option is A. ( Mostly bacteria are heterotrophic, but some are autotrophic )

According to the "Five kingdom system of classification" proposed by R. H. Whittaker in 1969, all living organisms are classified under 5 kingdoms. The names and characteristics are explained below.