Systematics Quick Kit: 20 MCQs with answers

G. Simpson

G. Simpson gave this definition in 1961. A. P. de Candolle introduced the term taxonomy, Carl Woese proposed the three-domain system, and Linnaeus introduced binomial nomenclature.

A. P. de Candolle

A. P. de Candolle, a Swiss botanist, first introduced the term taxonomy. G. Simpson defined systematics, Carl Woese proposed the three-domain system, and R. Sokal co-proposed numerical taxonomy.

Artificial classification

Artificial classification uses easily observable features like habit and colour, often ignoring evolutionary relationships. Linnaeus's system is an example. Natural classification uses significant features, and phylogenetic classification is based on evolutionary descent.

Phylogenetic classification

Phylogenetic classification is based on evolutionary descent, as seen in Engler and Prantl's classification. Artificial and natural classifications do not primarily focus on evolutionary relationships, and numerical taxonomy uses quantitative characters.

Archaea

Archaea are known for thriving in extreme environments. Bacteria differ from Archaea in cell wall structure, and Eukarya have eukaryotic cells. Fungi are a kingdom within Eukarya, not a domain.

Carl Woese

Carl Woese proposed the three-domain system (Archaea, Bacteria, Eukarya) in 1990. G. Simpson defined systematics, A. P. de Candolle introduced taxonomy, and R. Sokal co-proposed numerical taxonomy.

Chemical constituents of organisms

Chemotaxonomy classifies organisms based on chemical constituents, such as alkaloids in plants or peptidoglycan in bacterial cell walls. Morphological characters are used in traditional taxonomy, evolutionary descent in phylogenetic classification, and numerical values in numerical taxonomy.

DNA, RNA, and protein sequences

Molecular taxonomy uses molecular data such as DNA sequences, RNA sequences, and protein sequences to determine evolutionary relationships. Morphological characters are used in traditional taxonomy, chemical constituents in chemotaxonomy, and numerical values in numerical taxonomy.

Kingdom

Kingdom is the highest taxonomic category, composed of different sub-kingdoms. Class is a group of related orders, Division is a group of related classes, and Order is a group of related families.

Order

An order is a group of closely related families showing definite affinities. Class is a group of related orders, genus is a group of related species, and species is the basic unit.

Species

Species is the basic unit of classification. It is a group of organisms that can interbreed under natural conditions to produce fertile offspring. Genus is a group of related species, family is a group of related genera, and order is a group of related families.

Identifying species based on DNA sequence

DNA barcoding identifies species based on a short DNA sequence from a tissue sample. Chemotaxonomy uses chemical constituents, morphological taxonomy uses morphological characters, and numerical taxonomy uses numerical values.

Linnaeus

Linnaeus introduced binomial nomenclature, where each organism has a two-word name: genus and species. Carl Woese proposed the three-domain system, G. Simpson defined systematics, and A. P. de Candolle introduced taxonomy.

True

Numerical taxonomy is indeed also called Adansonian classification, named after Michel Adanson who emphasized the use of many characters.

Bentham and Hooker's system

Bentham and Hooker's system is a natural classification based on objectively significant features. Linnaeus's system is artificial, Engler and Prantl's is phylogenetic, and Woese's is based on molecular data.

Taxometrics

Numerical taxonomy is also called taxometrics or Adansonian classification. Chemosystematics is another name for chemotaxonomy, cladistics is a method of phylogenetic analysis, and molecular taxonomy uses molecular data.

R. Sokal and P. Sneath

R. Sokal and P. Sneath proposed numerical taxonomy in 1963. Carl Woese proposed the three-domain system, A. P. de Candolle introduced taxonomy, and Schleifer and Kandler proposed classification of bacteria based on peptidoglycan composition.

Kingdom, Division, Class, Order, Family, Genus, Species

The correct hierarchical sequence is Kingdom, Division (or Phylum), Class, Order, Family, Genus, Species. The other options are either reversed or incorrectly ordered.

Panthera

Panthera is a genus that includes tigers, lions, and leopards. Felidae is a family, Mammalia is a class, and Carnivora is an order.

True

Archaea lack peptidoglycan in their cell walls, whereas bacteria have peptidoglycan. This is a key difference between the two domains.