Free Biodiversity and Variety of Life MCQs with Answers

11. 'Taxon' is the unit of a group of:

• A. Order
• B. Taxonomy
• C. Species
• D. Genus

Explanation: Taxon refers to all the categories in the taxonomic hierarchy. It may be a kingdom, class, order, family, genus, or species. It is any level of grouping of organisms. Each of these categories has been divided further into intermediate categories like subkingdom, subdivision, superclass, subgenus, subspecies, etc. This term was coined by ICBN in 1956.

12. Linnaeus was credited with:

• A. Binomial nomenclature
• B. Theory of biogenesis
• C. Discovery of microscope
• D. Discovery of blood circulation

Explanation: Binomial nomenclature of scientific naming was first given by C. Linnaeus (1735) in his book Systema Naturae and later in "Species Plantarum" (1753). He used two Latin words for any organism, the first being a generic name and the second being a specific name. The generic name begins with a capital letter and the species name with a small letter. STB page # 83

13. Sequence of taxonomic categories is:

• A. Class-phylum-tribe-order-family-genus- species
• B. Division-class-family-tribe-order-genus- species
• C. Division-class-order-family-tribe-genus- species
• D. Phylum-order-class-tribe-family-genus- species

Explanation: According to Biosystematics, To construct the hierarchy of classification, one or more species are grouped into a genus, one or more genera into a family, families are clubbed into order, orders into class, classes into phylum, and various phyla into kingdom.

14. The term phylum was given by:

• A. Cuvier
• B. Haeckel
• C. Theophrastus
• D. Linnaeus

Explanation: The term phylum was coined in 1866 by Ernst Haeckel from the Greek phylon (φῦλον, "race, stock"), related to phyle (φυλή, "tribe, clan"). The concept of "phylum" was actually developed by the German biologist Ernst Haeckel (1834-1919) in the 19th century. Haeckel is credited with proposing the term "phylum" as a rank in the hierarchy of biological classification to group organisms with similar body plans and organizational features.

15. A group of plants or animals with similar traits of any rank is:

• A. Species
• B. Genus
• C. Order
• D. Taxon

Explanation: A taxon (plural taxa) or taxonomic unit, is a name designating an organism or group of organisms. A taxon is assigned a rank and can be placed at a particular level in a systematic hierarchy reflecting evolutionary relationships.

16. The basic unit or smallest taxon of taxonomy/classification is

• A. Species
• B. Kingdom
• C. Family
• D. Variety

Explanation: The basic unit or smallest taxon of taxonomy/classification is species. Species are a group of organisms that have numerous physical features in common and are capable of interbreeding and producing fertile offspring. Taxonomists use species as the starting point for organizing and categorizing living organisms into broader hierarchical groups. The hierarchy of biological classification, from most specific to most general.

17. Linnaeus evolved a system of nomenclature called:

• A. Mononomial
• B. Vernacular
• C. Binomial
• D. Polynomial

Explanation: Binomial nomenclature of scientific naming was first given by C. Linnaeus (1735) in his book Systema Naturae and later in "Species Plantarum" (1753). He used two Latin words for any organism, the first being a generic name and the second being a specific name. The generic name begins with a capital letter and the species name with a small letter.

18. Which of the following sets of diseases is caused by bacteria?

• A. Cholera and tetanus
• B. Typhoid and smallpox
• C. Tetanus and mumps
• D. Herpes and influenza

Explanation: Among all options, A is the correct one because both diseases are caused by bacteria. Cholera is caused by the bacterium Vibrio cholerae whereas tetanus is caused by the bacterium Clostridium tetani. All other options contain errors.

19. In higher vertebrates, the immune system can distinguish between self-cells and non-self-cells. If this property is lost due to genetic abnormality and it attacks self-cells, then it leads to:

• A. Autoimmune disease
• B. Active immunity
• C. Allergic response
• D. Graft rejection

Explanation: Autoimmunity is a disorder of the body's defense mechanisms in which an immune response is elicited against its own tissues, which are thereby damaged or destroyed. Autoimmunity may be caused due to genetic or environmental factors. This immune system dysfunction can result in a wide range of symptoms and health problems. There are more than 80 known autoimmune diseases, and they can affect virtually any part of the body.

20. If you suspect a major deficiency of antibodies in a person, to which of the following would you look for confirmatory evidence?

• A. Haemocytes
• B. Serum globulins
• C. Fibrinogen in plasma
• D. Serum albumins

Explanation: Serum globulins are proteins that include gamma globulins(antibodies) and a variety of enzymes and carrier/transport proteins. The specific profile of the globulins is determined by protein electrophoresis(SPEP), which separates the proteins according to size and charge. There are four major groups that can be identified: α-1 globulins, α-2 globulins, beta globulins, and gamma globulins. Once the abnormal group has been identified, further studies can determine the specific protein excess or deficit. Since the gamma fraction usually makes up the largest portion of the globulins, therefore antibody deficiency is mainly related to the low level of serum globulins.