Given the importance of this topic from competitive examinations like SSC CGL, UPSC in this article, we would look at the five-kingdom classification and kingdom Monera in detail.
1. The five kingdoms are Protista, Monera, Fungi, Plantae and Animalia.
2. Whittaker’s five-kingdom classification is based on the cell structure, thallus organisation, mode of nutrition, reproduction and phylogenetic relationships.
3. Monera: Proposed by Ernst Haeckel in the year 1866, this class comprises single-celled organisms known as unicellular organisms.
a. Cell type: Unicellular
b. Cell wall: Noncellulosic
c. Nuclear membrane: Absent
d. Mode of nutrition: Autotrophic (chemosynthetic and photosynthetic) and Heterotrophic (saprophytic/ parasitic).
4. Bacteria are the sole members of kingdom Monera. They occur abundantly in most extreme conditions too. For eg. Hot springs, deserts, snow and deep oceans.
5. On the basis of their shapes, bacteria are divided into four categories: spherical coccus, rod-shaped bacillus, comma-shaped vibrios and the spiral spirillum.
6. Bacteria show extensive metabolic diversity. Few bacteria are autotrophic (they synthesise their own food from inorganic substances) in nature while others are heterotrophic (depend on other organisms or dead organic matter).
7. Archaebacteria: Now known as archaea, this special class of bacteria exist in the very harsh environments (resembling the ancient bacteria). Its different types include, Methanogens (produce methane gas as a by-product of their metabolism), halophiles (survive in extremely high salt concentrations) and thermophiles (tolerate high temperatures).
8. Eubacteria (true bacteria): These bacteria have a distinct cell wall and a flagellum, if they are motile. These can be gram positive or gram negative in nature based on the cell wall composition. Cyanobacteria (also known as blue green algae) are a sub-group of eubacteria that obtain energy through photosynthesis. Some of these bacteria fix atmospheric nitrogen in specialised cells called heterocysts.
9. Heterotrophic bacteria are most abundant in nature and most of them are decomposers.
10. Production of curd from milk, antibiotics, and vaccines are some of the important uses of heterotrophic bacteria. Saccharomyces cerevisiae is used in the production of alcohol while lactobacillus is responsible for the formation of curd. On the other hand, some of them are pathogens harming humans and animal life. Cholera, typhoid, tetanus, etc are few of the well-known diseases caused by bacteria. Vibrio cholerae is the causative agent for cholera.
11. Mycoplasma are organisms that completely lack a cell wall. They are the smallest living cells known and can survive without oxygen. Many mycoplasma are pathogenic in animals and plants.
General Knowledge and Current Affairs are an important component of many competitive exams, such as the UPSC Civil Services Examination, SSC CGL Exam, Bank PO & other PSU entrance tests, etc. Therefore, understanding the concepts/terms/events that are significant in our daily lives is critical for aspirants. To make your preparation easier and to help you score better in your exams, we at PaGaLGuY bring you brief articles on important phenomena, concepts and events. Spend just 15 minutes every day on pagalguy.com and score at least 10 more marks in your General Studies paper!
Link to Classification of organisms capsule 1:
Link to Classification of organisms capsule 3:
To get fresh updates about different exams on your Facebook & Twitter timelines, subscribe to our pages created specifically for them. We will post only exam specific links on these pages:
Bank PO:
Facebook: https://www.facebook.com/pagalguybankpo
Twitter: https://twitter.com/PaGaLGuYBankPO
SSC – CGL:
Facebook: https://www.pagalguy.com/ssc
Twitter: https://twitter.com/pagalguyssc
UPSC:
Facebook: https://www.facebook.com/pages/Pagalguy-UPSC/951926044840262
Twitter: https://twitter.com/PaGaLGuYUPSC