[Biology Class Notes] on Types of Organisms Pdf for Exam

Different Types of Organisms

The term organism derived from the Greek word “organismos”, which means any kind of organism. Taxonomy classifies the organism in several groups according to their morphological and anatomical characteristics. An organism can develop with the course of time, it reproduces and it can respond to stimuli. The organism may be prokaryotes or it is also considered to be eukaryotes. Prokaryotes are the cells or organisms that lack a proper nucleus and membrane-bound organelles. On the other hand, eukaryotes are the cell or organisms that have a proper distinguishing nucleus and membrane-bound organelles. All organisms are considered to be the basic aspect of the form of life on the earth.

Types of Organisms

On the basis of mode of nutrition, organisms can be differentiated in 2 types. 

For Example: Plants

It can be further divided into 7 types.

• Herbivores: Herbivores feed on the plants and vegetative materials.
  Example: cow, goat

• Carnivores: Carnivores are the organisms that feed on the flesh of other animals.
  Example: tiger, lion

• Omnivores: These are organisms that eat both plants and animals.
  Example: crow, hen

• Parasites: Parasites are the organisms that live on the body of other animals and take nutrients from that host body. It causes damage to the host body and eventually kills it.
  Example: Tapeworm, Flea

• Scavengers: Scavengers are the organisms that feed on dead and decaying animals or plants.
  Example: Hyenas, Coyotes.

• Decomposers: They breakdown the dead plant or organisms and feed on the organic matter produced due to breakdown.
  Example: Winter fungus, Slugs.  

Types of Kingdoms in Biology

In 1969 R.H. Whittaker divided the organisms on the basis of cell structure, mode of nutrition, body organization, and reproduction.

• Kingdom Monera – Kingdom monera contains all the unicellular organisms with prokaryotic cells containing the 70S ribosome. It’s further divided into three phyla types,i.e, archaebacteria, eubacteria, cyanobacteria.

• Kingdom Protista – Kingdom Protista consists of unicellular organisms with a eukaryotic cell. All organisms have a well-defined nucleus and membrane-bound organelles in their cells.

• Kingdom Fungi – All organisms of this kingdom are multicellular eukaryotes. The organisms can reproduce sexually or asexually. Kingdom fungi are further divided into five phyla, i.e, Chytridiomycosis, Ascomycota, Glomeromycota, Basidiomycota.

• Kingdom Animalia – Kingdom Animalia consist of eukaryotic animals. They do not possess chlorophyll in their body. They are further divided into 11 phyla,i.e, Porifera, Cnidarian, Ctenophore, Platyhelminthes, Aschelminthes, Annelida, arthropods, Mollusca, Echinodermata, Hemichordate, Chordate.

• Kingdom Plantae – Kingdom Plantae consists of all plants and the majority of them are autotrophs as they have chlorophyll and they use photosynthesis to produce their food. This kingdom is further divided into five phyla, i.e, Thallophyta, Bryophyte, Pteridophyta, Gymnosperms, Angiosperms. 

5 Types of Microorganisms

Microorganisms are tiny organisms that exist as unicellular, multicellular, or cluster of cells on the earth.

Some examples are rod-shaped – bacillus, spiral shape – spirilla, spherical shape – coccus, curved shape – vibrio.

• Fungi – These are the multicellular eukaryotic microscopic organisms. They have a cell wall made up of chitin and they reproduce through spores.

• Protozoa – These are the unicellular eukaryotic microscopic organisms. They are considered to be aerobic which further states that they need air or O2 to survive.

• Algae – These are autotrophic microorganisms and are also known as blue-green algae or cyanobacteria. They are found to live in a moist habitat.

• Virus – Virus is the non-cellular microscopic organism. They only consist of nucleic acid that is DNA or either RNA. They can reproduce only in a host body.