Taxonomy Archives

61. Yeast, which is used to make bread, belongs to the group :

Yeast, which is used to make bread, belongs to the group :

[amp_mcq option1=”Protista” option2=”Fungi” option3=”Monera” option4=”Protozoa” correct=”option2″]

This question was previously asked in

UPSC CDS-1 – 2022

Yeast, commonly used in baking and fermentation, belongs to the group Fungi.

Yeast are eukaryotic, single-celled microorganisms. They are classified within the Kingdom Fungi. The most common species used in bread making is *Saccharomyces cerevisiae*.

Protista is a diverse kingdom of eukaryotic organisms that are not plants, animals, or fungi (e.g., amoeba, algae). Monera is an outdated kingdom that included prokaryotic organisms (bacteria and archaea). Protozoa is a group of single-celled eukaryotes, now typically classified within the Kingdom Protista.

62. Which one of the following pairs of animals is warm-blooded?

Which one of the following pairs of animals is warm-blooded?

[amp_mcq option1=”Crocodile and Ostrich” option2=”Hagfish and Dogfish” option3=”Tortoise and Ostrich” option4=”Peacock and Camel” correct=”option4″]

This question was previously asked in

UPSC CDS-1 – 2019

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Warm-blooded (endothermic) animals are those that maintain a stable internal body temperature regardless of the external environment. Birds (like Peacock and Ostrich) and mammals (like Camel) are warm-blooded. In option D, both Peacock (a bird) and Camel (a mammal) are warm-blooded animals.

Birds and Mammals are warm-blooded (endothermic).

Crocodiles and Tortoises are reptiles, which are cold-blooded (ectothermic). Hagfish and Dogfish are fish, which are also cold-blooded.

63. Which one of the following has a bilateral symmetry in its body

Which one of the following has a bilateral symmetry in its body organization?

[amp_mcq option1=”Asterias” option2=”Sea anemone” option3=”Nereis” option4=”Echinus” correct=”option3″]

This question was previously asked in

UPSC CDS-1 – 2019

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Nereis is a marine polychaete worm belonging to the phylum Annelida. Annelids typically exhibit bilateral symmetry, where the body can be divided into two mirror-image halves along a single sagittal plane.

Bilateral symmetry divides an organism into two symmetrical halves (left and right).

Asterias (starfish) and Echinus (sea urchin) are echinoderms, which typically exhibit radial symmetry (specifically, pentamerous radial symmetry in adults). Sea anemones belong to the phylum Cnidaria and exhibit radial symmetry.

64. Which one of the following is a true fish as per the biological system

Which one of the following is a true fish as per the biological system of classification?

[amp_mcq option1=”Silverfish” option2=”Jellyfish” option3=”Cuttlefish” option4=”Flying fish” correct=”option4″]

This question was previously asked in

UPSC CDS-1 – 2018

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The question asks which option represents a ‘true fish’ according to biological classification. True fishes belong to the superclass Pisces (or equivalent phylogenetic groups like Osteichthyes and Chondrichthyes). Let’s examine the options:
A) Silverfish: This is an insect (Zygentoma order), not a fish.
B) Jellyfish: This is a marine invertebrate belonging to the phylum Cnidaria, not a fish.
C) Cuttlefish: This is a marine mollusc belonging to the class Cephalopoda, not a fish.
D) Flying fish: This is a type of marine ray-finned bony fish belonging to the family Exocoetidae. It is a true fish.

In everyday language, ‘fish’ is often used loosely, but in biology, a ‘true fish’ refers to aquatic vertebrates with gills that lack limbs with digits, typically belonging to the superclass Pisces.

Many animals with “fish” in their common name are not true fish (e.g., starfish, crayfish, shellfish). True fish include cartilaginous fish (sharks, rays) and bony fish (most common fish).