Taxonomy

41. As per the code of the nomenclature, which one of the following is the

As per the code of the nomenclature, which one of the following is the correct way of writing a biological name?

[amp_mcq option1=”Amoeba Proteus” option2=”Amoeba proteus” option3=”amoeba proteus” option4=”Amoeba Proteus” correct=”option2″]

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UPSC NDA-1 – 2019
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The correct way of writing a biological name as per the code of nomenclature is ‘Amoeba proteus’.
In binomial nomenclature, the genus name starts with a capital letter, and the species name starts with a small letter. Both names are typically italicized or underlined.
This system of nomenclature was largely developed by Carl Linnaeus. It provides a unique and internationally recognized name for each species. When handwritten, the genus and species names are usually underlined separately; when printed, they are typically italicized.

42. Which one of the following organisms has vascular tissues ?

Which one of the following organisms has vascular tissues ?

[amp_mcq option1=”Cladophora” option2=”Penicillium” option3=”Marsilea” option4=”Anabaena” correct=”option3″]

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UPSC NDA-1 – 2019
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The correct answer is C) Marsilea.
Vascular tissues (xylem and phloem) are present in vascular plants (Tracheophytes), which include pteridophytes (ferns), gymnosperms, and angiosperms. Marsilea is a genus of ferns, which belong to the group Pteridophyta. Cladophora is a green alga, Penicillium is a fungus, and Anabaena is a cyanobacterium; none of these groups of organisms possess vascular tissues.
Algae, fungi, and bacteria are considered non-vascular organisms. The development of vascular tissues was a significant evolutionary step that allowed plants to grow larger and colonize terrestrial environments more effectively by facilitating efficient transport of water, nutrients, and sugars.

43. Which one of the following is the correct sequence of levels of hierar

Which one of the following is the correct sequence of levels of hierarchy of classification of organisms from higher to lower ?

[amp_mcq option1=”Phylum – Class – Order – Family – Genus” option2=”Phylum – Class – Family – Order – Genus” option3=”Family – Order – Class – Species – Genus” option4=”Class – Family – Order – Species – Genus” correct=”option1″]

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UPSC NDA-1 – 2018
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Option A presents the correct sequence of classification levels from higher to lower among the given choices: Phylum – Class – Order – Family – Genus.
The standard hierarchical levels of classification are Kingdom, Phylum, Class, Order, Family, Genus, and Species, from highest to lowest.
Taxonomic hierarchy is a system used to group organisms based on shared characteristics. Each level is called a taxon. The sequence provided in option A is a correct subset of this hierarchy. Other options show incorrect arrangements of these levels.

44. Which one of the following statements about classification of plants i

Which one of the following statements about classification of plants is correct ?

[amp_mcq option1=”Thallophytes have well differentiated body design” option2=”Funaria is a fungus” option3=”All Pteridophytes are Phanerogams” option4=”Vascular system is not found among Bryophytes” correct=”option4″]

This question was previously asked in
UPSC NDA-1 – 2018
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Statement D is correct. Bryophytes are non-vascular plants, meaning they lack specialized vascular tissues like xylem and phloem for the transport of water and nutrients.
– Bryophytes (like mosses, liverworts, and hornworts) are the first plants to colonize land but lack true vascular tissues, stems, roots, and leaves.
– Vascular tissue first evolved in Pteridophytes.
– Thallophytes (Algae, Fungi, Lichens) have a relatively undifferentiated body design (thallus), unlike the statement A suggests.
– Funaria is a genus of moss, belonging to the Bryophyta, not a fungus. Fungi are heterotrophic organisms belonging to a separate kingdom.
– Phanerogams are seed-bearing plants (Gymnosperms and Angiosperms). Pteridophytes (ferns, horsetails) reproduce by spores and are classified as Cryptogams. Therefore, not all Pteridophytes are Phanerogams.

45. Consider the following statements: 1. All Echinoderms are not marine

Consider the following statements:

  • 1. All Echinoderms are not marine.
  • 2. Sponges are exclusively marine.
  • 3. Insects are found in all kinds of habitats.
  • 4. Many primates are arboreal.

Which of the statements given above is/are correct ?

[amp_mcq option1=”1, 3 and 4 only” option2=”3 and 4 only” option3=”2 and 4 only” option4=”3 only” correct=”option2″]

This question was previously asked in
UPSC NDA-1 – 2016
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The correct answer is B) 3 and 4 only.
Let’s examine each statement:
1. All Echinoderms are not marine: This statement is incorrect. Echinodermata (which includes starfish, sea urchins, sea cucumbers, brittle stars, and crinoids) is a phylum consisting *entirely* of marine animals. There are no freshwater or terrestrial echinoderms.
2. Sponges are exclusively marine: This statement is incorrect. While the vast majority of sponges (Phylum Porifera) are marine, there are a number of species found in freshwater habitats (e.g., the family Spongillidae).
3. Insects are found in all kinds of habitats: This statement is correct. Insects (Class Insecta) are the most diverse group of animals and have colonized almost every habitat on Earth, including terrestrial, freshwater, and some marine environments (coastal areas, surface films, etc.). They are absent from the open ocean deep sea.
4. Many primates are arboreal: This statement is correct. Arboreal animals live in trees. Many species of primates (like most monkeys and some apes) are well-adapted for life in trees and spend most of their time in forest canopies.
Based on the analysis, statements 3 and 4 are correct.
Echinoderms are known for their radial symmetry (usually pentaradial in adults) and unique water vascular system. Sponges are simple multicellular animals, filter feeders, lacking true tissues and organs. Insects are characterized by a chitinous exoskeleton, a three-part body (head, thorax, and abdomen), three pairs of jointed legs, compound eyes, and typically two pairs of wings. Primates are characterized by traits like relatively large brains, grasping hands and feet, and forward-facing eyes.

46. Microscopic, branched and thread-like structures, which can grow and a

Microscopic, branched and thread-like structures, which can grow and absorb nutrition from organic matter, are found in

[amp_mcq option1=”bacteria” option2=”viruses” option3=”fungi” option4=”algae” correct=”option3″]

This question was previously asked in
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The correct answer is fungi.
Fungi are characterized by their vegetative structure, which consists of microscopic, branched, thread-like filaments called hyphae. These hyphae grow through organic matter and absorb nutrients, as fungi are heterotrophic organisms.
Bacteria are unicellular and lack hyphae. Viruses are obligate intracellular parasites and do not grow or absorb nutrition in this manner. Algae are photosynthetic organisms and their structure is typically different from the filamentous hyphae found in fungi, though some algae can be filamentous.

47. Which of the following is a true fish ?

Which of the following is a true fish ?

[amp_mcq option1=”Jellyfish” option2=”Silverfish” option3=”Starfish” option4=”Sea horse” correct=”option4″]

This question was previously asked in
UPSC Geoscientist – 2024
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The term “true fish” in a biological context refers to aquatic vertebrates belonging to the superclass Pisces. These animals are characterized by features such as gills for breathing oxygen from water, fins for locomotion, and typically scales. Many animals are commonly called “fish” but do not fit this biological definition.
– **Jellyfish:** These are marine invertebrates belonging to the phylum Cnidaria. They are not fish.
– **Silverfish:** These are small, wingless insects belonging to the order Zygentoma. They are not fish.
– **Starfish:** These are marine invertebrates belonging to the phylum Echinodermata. They are not fish.
– **Sea horse:** Sea horses are marine vertebrates belonging to the genus *Hippocampus*. They are a type of bony fish (class Actinopterygii).
Identifying “true fish” requires understanding basic zoological classification. The common names of many marine invertebrates include “fish” (e.g., shellfish, crayfish), leading to confusion. However, biologically, “fish” refers specifically to the aquatic vertebrates that breathe with gills and have fins.

48. Which one of the following ‘algae’ is not known identified partner to

Which one of the following ‘algae’ is not known identified partner to form lichen?

[amp_mcq option1=”Nostoc” option2=”Stigonema” option3=”Trentepohlia” option4=”Vaucheria” correct=”option4″]

This question was previously asked in
UPSC Geoscientist – 2023
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Lichens are formed through a symbiotic association between a fungus (mycobiont) and a photosynthetic partner (photobiont), which is usually a green alga or a cyanobacterium. Common algal photobionts belong to genera like Trebouxia, Trentepohlia, and Pseudotrebouxia. Cyanobacterial photobionts include genera like Nostoc and Stigonema. Vaucheria is a filamentous alga belonging to the Xanthophyceae (yellow-green algae) and is not a commonly known or identified photobiont partner in lichen formation.
– Lichens are symbioses between fungi and photosynthetic organisms (algae or cyanobacteria).
– Nostoc and Stigonema are cyanobacteria known to form lichen associations.
– Trentepohlia is a green alga known to form lichen associations.
– Vaucheria is a yellow-green alga not typically found as a lichen photobiont.
The majority of lichen photobionts are green algae (~90%), with cyanobacteria making up most of the remainder. The specific species involved are often highly specialized for the symbiotic relationship.

49. Which one of the following is defined as a natural biological unit tie

Which one of the following is defined as a natural biological unit tied together by the sharing of a common gene pool?

[amp_mcq option1=”Vegetation” option2=”Flora” option3=”Fauna” option4=”Species” correct=”option4″]

This question was previously asked in
UPSC Geoscientist – 2023
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A species is defined as a natural biological unit tied together by the sharing of a common gene pool.
In biology, a species is typically defined as a group of organisms that can interbreed in nature and produce fertile offspring. This reproductive isolation maintains the gene pool of the species as a distinct unit. Vegetation refers to the plant life of a region, Flora refers specifically to the plant species, and Fauna refers to the animal species. None of these represent a single biological unit defined by a shared gene pool in the same way as a species.
There are various concepts of species (e.g., biological species concept, morphological species concept, phylogenetic species concept), but the biological species concept, based on reproductive isolation and a shared gene pool, is widely used, especially for sexually reproducing organisms.

50. Which one of the following groups contributes the maximum number of sp

Which one of the following groups contributes the maximum number of species to the biosphere?

[amp_mcq option1=”Reptiles” option2=”Mammals” option3=”Insects” option4=”Birds” correct=”option3″]

This question was previously asked in
UPSC Geoscientist – 2022
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Insects constitute the largest group of animals on Earth, both in terms of the number of species and the number of individuals. Their diversity far surpasses that of reptiles, mammals, or birds.
– Insects belong to the class Insecta, which is the most speciose class within the phylum Arthropoda.
– Estimates for the number of insect species vary widely, but most sources agree that there are millions of species, significantly more than all other animal groups combined.
Other highly diverse groups include fungi, bacteria, and certain plant groups, but among the animal groups listed in the options, insects are overwhelmingly the most numerous in terms of species count in the biosphere.
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