The Two Kingdom system of classification was given by Carl Linnaeus Father of Taxonomy, It includes
1. Kingdom Plantae 2. Kingdom Animalia
Kingdom Plantae
It includes organisms having the following features
- The cell wall is present (+)
- The locomotion is absent (-)
- Nutrition is autotrophic
- The Response to external stimulus is poor
- It includes Bacteria, Fungi, Algae, Bryophytes, Pteridophytes, Gymnosperms, and Angiosperms.
Kingdom Animalia
It has the following features
- The cell wall is absent (-)
- The locomotion is present (+)
- Nutrition is Heterotrophic
- Response to external stimulus is strong
- It includes Protozoans, Invertebrates, and Vertebrates.
Disadvantages of the two-kingdom classification system
The two-kingdom system seems to be inadequate or unsatisfactory because of the following difficulties
- The differentiation between prokaryotes and eukaryotes is absent and was grouped.
- There was no differentiation between autotrophic and heterotrophic organisms and were placed together.
- There was no differentiation between unicellular and multicellular organisms, these were placed together.
- Some organisms having both features of plants as well as animals were not placed in any kingdom.
- Viruses and viroids were not placed in any kingdom.
- Dual organisms
Dual Organisms are those organisms that possess characters of plants as well as animals.Chlamydomonas, Euglena, etc
Chlamydomonas
It is also called Snow algae. It is a unicellular flagellate Eukaryotic organism. It is also called a Model organism. It has a cell wall and has an autotrophic mode of nutrition. thus showing characteristics of plants. The Chlamydomonas also have flagella due to the presence of flagella it shows locomotion and also possesses a contractile vacuole thus it resembles animals. That is why it is known as a Dual organism because it has both characters of plants as well animals.
Euglena
It’s a flagellate Eukaryotic creature with only one cell. The nutrition in Euglena is Auto-trophic mode and resemblances with plants while as it also shows locomotion due to the presence of flagella and thus resemblances with animals. it is also called a dual organism because it has both characters of plants as well as animals.
Five-kingdom system of classification: Definition and Characters
Hello, dear students today we will discuss the Five-kingdom system of classification, it was R.H. Whittaker in 1969 classified organisms into Kingdom Plantae, Kingdom Animalia, Kingdom Protista, Kingdom Monera, and New one Kingdom Fungi.
Characters for 5 kingdom classification
1. The organism is pro-karyotic or eu-karyotic
2.The organism is unicellular or multicellular
3. The living being is auto-trophic or hetero-trophic, if the living being is hetero-trophic it is three types
A. parasitic B. saprophytic C. holozoic
4. Reproduction refers to whether the individual perform asexually, sexually or both
5. Evolutionary relationship describes how a new individual evolved from an older one, how creation took place
For some characters, an analysis of five kingdoms was made
Kingdom Monera
1. Cell type: It has prokaryotic cellular organization.
2. Cell wall: There is a cell wall, but it is non-cellulosic.
3. Nuclear membrane: It is absent.
4. Body organization: The Monera possess unicellular organization
5. Mode of nutrition: The monera are autotrophic as well as heterotrophic in nutrition. These may be Photo-autotrophic and chemo-autotrophs. The heterotrophic may be parasitic, saprophytic.
Kingdom Protista
1. Cell type: The cellular organization is present (Eukaryotic)
2. Cell wall: It is present (+)
3. Nuclear membrane: It is present(+)
4. It has a uni-cellular eukaryotic body structure
5. Nutritional mode: Both autotrophic, as well as hetero-trophic nutrition, is present. these may be photo-autotrophs. there are still parasitic, saprophytic, and holozoic forms.
Kingdom Fungi
1. Cell type: The fungi possess a eukaryotic cellular organization
2. Cell wall: The cell wall is present but non-cellulosic, it is built of chitin
3. Nuclear membrane is present
4. Body organization: They have multicellular body organization having loose tissue. the well-developed tissue organization is absent
Kingdom Plantae
1. Cell type: Eukaryotic cellular organization is present
2. Cell wall: It is present but cellulosic
3. Nuclear membrane is present
4. Mode of Nutrition: They are Auto-trophic and photo-Autotrophs.
Kingdom Animalia
1. It has a cellular organization that is Eu-karyotic
2. It has no cell wall
3. Nuclear organization is located in the nucleus
4. They have tissue and organ level organization
5. They have heterotrophic nutrition
Here are some significant disadvantages
1. The kingdoms of algae were split into three groups monera Protista and Plantae
2. In monera blue-green algae was placed
3. No viruses have been seen in any of the systems