Taxonomy

31. Which of the following kingdoms has/have only unicellular organisms?

Which of the following kingdoms has/have only unicellular organisms?

[amp_mcq option1=”Monera only” option2=”Protista only” option3=”Monera and Protista both” option4=”Protista and Fungi both” correct=”option1″]

This question was previously asked in
UPSC NDA-2 – 2018
Download PDFAttempt Online
The kingdom Monera consists only of unicellular organisms.
– In the five-kingdom classification system, Monera includes all prokaryotic organisms, such as bacteria and cyanobacteria, which are exclusively unicellular.
– Protista primarily consists of unicellular eukaryotic organisms, but some simple multicellular or colonial forms are also classified under Protista depending on the system.
– Fungi includes both unicellular (like yeast) and multicellular organisms.
– Plantae and Animalia consist entirely of multicellular organisms.
The question asks which kingdom *only* has unicellular organisms. While Protista is predominantly unicellular, Monera is strictly unicellular. Thus, Monera is the most accurate answer meeting the condition of having *only* unicellular organisms.

32. A horse and a donkey can breed to produce mule which is an infertile a

A horse and a donkey can breed to produce mule which is an infertile animal. The infertility is because horse and donkey belong to different

[amp_mcq option1=”class” option2=”order” option3=”species” option4=”genus” correct=”option3″]

This question was previously asked in
UPSC NDA-2 – 2016
Download PDFAttempt Online
Mules are infertile because horses and donkeys belong to different species.
A species is generally defined as a group of organisms that can interbreed and produce fertile offspring. While horses (Equus caballus) and donkeys (Equus asinus) can interbreed to produce a mule (or a hinny), their offspring are almost always sterile. This sterility arises because horses and donkeys have different numbers of chromosomes (horses have 64, donkeys have 62). The mule inherits 63 chromosomes, which cannot pair properly during meiosis, preventing the formation of viable gametes (sperm or eggs), thus leading to infertility.
Horses and donkeys belong to the same genus, Equus, which indicates a relatively recent common ancestor compared to differences at the order or class level. The ability to produce hybrid offspring, even if infertile, is common between closely related species within the same genus.

33. Malarial parasite is a

Malarial parasite is a

[amp_mcq option1=”bacteria” option2=”protozoa” option3=”virus” option4=”fungus” correct=”option2″]

This question was previously asked in
UPSC NDA-2 – 2016
Download PDFAttempt Online
The malarial parasite, Plasmodium, is a single-celled eukaryotic organism belonging to the phylum Apicomplexa. Organisms in this group are commonly classified as protozoa.
Protozoa are diverse group of unicellular eukaryotic organisms, many of which are motile and include parasitic forms like Plasmodium.
Malaria is caused by the Plasmodium parasite, which is transmitted to humans through the bite of infected female Anopheles mosquitoes. Bacteria are prokaryotic; viruses and fungi are different classes of microorganisms.

34. In which one of the following, methano- gens, i.e., methane producing

In which one of the following, methano- gens, i.e., methane producing bacteria are not present ?

[amp_mcq option1=”Rumen of cattle” option2=”Aerobic environment” option3=”Anaerobic sludge” option4=”Excreta of cattle” correct=”option2″]

This question was previously asked in
UPSC NDA-2 – 2016
Download PDFAttempt Online
Methanogens are a group of anaerobic archaea that produce methane as a metabolic byproduct in anoxic conditions. They are strictly anaerobic, meaning oxygen is toxic to them.
Methanogens thrive in environments where oxygen is absent and organic matter is undergoing decomposition. Examples include the digestive tracts of ruminants (like cattle rumen), anaerobic sludge digesters in wastewater treatment, and sediments in swamps and marshes.
The rumen of cattle is a highly anaerobic environment where methanogens play a crucial role in the digestion of cellulose. Anaerobic sludge in sewage treatment plants is another common habitat. Cattle excreta, being partially digested material from the rumen and exposed to anaerobic conditions during storage, also contains active methanogens. An aerobic environment, however, is unsuitable for methanogens due to the presence of oxygen.

35. Living things are grouped into subgroups like plant kingdom / animal k

Living things are grouped into subgroups like plant kingdom / animal kingdom. Which one of the following is not correct for animal kingdom?

[amp_mcq option1=”Cannot make their own food” option2=”Body contains cellulose” option3=”Do not have chlorophyll” option4=”Migrate from one place to another” correct=”option2″]

This question was previously asked in
UPSC NDA-2 – 2015
Download PDFAttempt Online
The correct answer is B. Animal bodies do not contain cellulose as a structural component.
– Statement A is correct: Animals are heterotrophs; they cannot produce their own food and obtain energy by consuming other organisms.
– Statement B is incorrect: Cellulose is a complex carbohydrate that is the main structural component of cell walls in plants. Animal cells do not have cell walls, and their bodies are not primarily composed of cellulose. Some animals (like termites) can digest cellulose with the help of symbiotic microorganisms, but their bodies themselves do not contain it structurally.
– Statement C is correct: Animals lack chlorophyll, the pigment necessary for photosynthesis, unlike plants.
– Statement D is generally correct: Most animals are motile, meaning they can move from one place to another, which is a key characteristic distinguishing them from sessile plants (though some animals are sessile, like sponges).
The animal kingdom (Kingdom Animalia) is characterized by eukaryotic, multicellular organisms that are heterotrophic and typically develop from an embryo. Key characteristics include lack of cell walls, presence of nervous tissue and muscle tissue (in most), and mobility (in most).

36. Which one of the following statements about bryophytes is not correct

Which one of the following statements about bryophytes is not correct ?

[amp_mcq option1=”The plant body is a gametophyte.” option2=”They are also called the amphibians of plant kingdom.” option3=”The plant body is attached to the substratum by rhizoids.” option4=”Specialized water-conducting tissues are present.” correct=”option4″]

This question was previously asked in
UPSC NDA-1 – 2023
Download PDFAttempt Online
Bryophytes are non-vascular plants, which means they lack specialized vascular tissues like xylem and phloem for the efficient transport of water, minerals, and sugars over long distances. While they may have some rudimentary conducting cells, they do not possess the well-developed, specialized vascular tissues found in tracheophytes (ferns, gymnosperms, angiosperms).
– Bryophytes are non-vascular plants.
– They lack specialized water-conducting tissues (xylem) and nutrient-conducting tissues (phloem).
– The dominant phase of the life cycle is the gametophyte.
– They are often called amphibians of the plant kingdom because they require water for fertilization.
– They are anchored to the substratum by rhizoids.
The absence of true vascular tissues limits the size of bryophytes and their ability to colonize dry environments efficiently. Water absorption primarily occurs directly through the plant surface.

37. Which one of the following is not a characteristic feature of fungi ?

Which one of the following is not a characteristic feature of fungi ?

[amp_mcq option1=”Cell wall is made of chitin” option2=”Filamentous mycelium is present” option3=”Can carry out photosynthesis” option4=”Asexual spores are produced” correct=”option3″]

This question was previously asked in
UPSC NDA-1 – 2023
Download PDFAttempt Online
Fungi are eukaryotic organisms that belong to their own kingdom. They are heterotrophs, meaning they obtain nutrients by absorbing organic matter from their environment. They lack chloroplasts and the necessary machinery for photosynthesis. Therefore, the ability to carry out photosynthesis is not a characteristic feature of fungi.
– Fungi are heterotrophic organisms.
– They lack chloroplasts.
– They cannot perform photosynthesis.
– Other listed options (cell wall of chitin, filamentous mycelium, asexual spores) are characteristic features of many fungi.
The cell wall of fungi is typically composed of chitin, a tough polysaccharide. Many fungi grow as a network of filamentous structures called hyphae, collectively forming a mycelium. Fungi reproduce asexually and/or sexually, often producing spores.

38. Organisms capable of using CO₂ as principal carbon source are called :

Organisms capable of using CO₂ as principal carbon source are called :

[amp_mcq option1=”Autotrophs” option2=”Heterotrophs” option3=”Parasites” option4=”Decomposers” correct=”option1″]

This question was previously asked in
UPSC NDA-1 – 2023
Download PDFAttempt Online
Organisms capable of using CO₂ as a principal carbon source are called Autotrophs.
Autotrophs are organisms that can produce their own food using light, water, carbon dioxide, or other chemicals. They are the producers in an ecosystem. They use inorganic sources, like CO₂, to synthesize organic compounds. Photosynthesis is the most common form of energy production for autotrophs, using sunlight to convert CO₂ and water into glucose. Chemosynthesis is another process used by some autotrophs, utilizing energy from chemical reactions.
Heterotrophs, on the other hand, obtain energy and carbon by consuming other organisms or organic matter. Parasites are a type of heterotroph that lives on or inside another organism (the host) and benefits at the host’s expense. Decomposers are heterotrophs that break down dead organic material, returning nutrients to the environment.

39. Which one of the following groups is called ‘amphibians of plant

Which one of the following groups is called ‘amphibians of plant kingdom’?

[amp_mcq option1=”Bryophytes” option2=”Thallophytes” option3=”Pteridophytes” option4=”Gymnosperms” correct=”option1″]

This question was previously asked in
UPSC NDA-1 – 2022
Download PDFAttempt Online
Bryophytes, which include mosses, liverworts, and hornworts, are often referred to as the ‘amphibians of the plant kingdom’. This is because, while they are terrestrial plants inhabiting damp environments, they are dependent on water for fertilization. The male gametes (sperms) of bryophytes are motile and require a film of water to swim to the egg cell. This dependence on water for reproduction is analogous to how amphibians (like frogs) live on land but require water for breeding.
Bryophytes require water for sexual reproduction, linking their life cycle to moist environments, hence the term ‘amphibians of the plant kingdom’.
Thallophytes is an older, artificial grouping. Pteridophytes (ferns) are vascular plants that also require water for fertilization, but bryophytes represent an earlier evolutionary step towards land plants and are more strongly associated with this term. Gymnosperms and Angiosperms are fully terrestrial and do not require external water for fertilization (pollen is transferred by wind, insects, etc.).

40. Which one of the following belongs to ‘Pisces’?

Which one of the following belongs to ‘Pisces’?

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

This question was previously asked in
UPSC NDA-1 – 2022
Download PDFAttempt Online
‘Pisces’ is a traditional classification group that includes all fish. Dogfish (a type of shark) is a cartilaginous fish belonging to the class Chondrichthyes, which falls under Pisces. Jellyfish belong to the phylum Cnidaria, Silverfish are insects belonging to the phylum Arthropoda, and Starfish belong to the phylum Echinodermata. None of Jellyfish, Silverfish, or Starfish are fish (Pisces).
Pisces includes all true fish (aquatic vertebrates with gills, fins, and typically scales). Many organisms with “fish” in their name are not true fish.
The term ‘Pisces’ is often used as a superclass encompassing the classes Chondrichthyes (cartilaginous fish) and Osteichthyes (bony fish), and sometimes the jawless fishes (Agnatha). Modern classification often replaces Pisces with specific classes like Chondrichthyes, Actinopterygii, Sarcopterygii, etc.
Page 1Page 2Page 3Page 4Page 5