BIOLOGY NEET PYQ QUIZ : ALL CHAPTERS

Explanation: Diatoms are photosynthetic organisms and are major components of marine phytoplankton.

Explanation:
A genus contains one or more closely related species. Therefore, species is more specific and has fewer but more closely shared characteristics.

Hierarchy:

Kingdom
↓
Phylum/Division
↓
Class
↓
Order
↓
Family
↓
Genus
↓
Species

Explanation: Archaebacteria include halophiles, thermoacidophiles and methanogens, many of which occupy unusual or extreme habitats.

Explanation: Bacterial flagella are specialised structures involved primarily in locomotion. A bacterial flagellum consists of a filament, hook and basal body.

Explanation: R.H. Whittaker proposed the five-kingdom classification in 1969. The kingdoms are Monera, Protista, Fungi, Plantae and Animalia.

Explanation:
The correct convention is:

Genus begins with a capital letter.

Specific epithet begins with a small letter.

Printed scientific names are italicised.

When handwritten, the two words are separately underlined.

Example:

Mangifera indica

Not:

Mangifera Indica

Explanation:

Family → Muscidae

Order → Diptera

Class → Insecta

Phylum → Arthropoda

Therefore:

A-III, B-I, C-IV, D-II

Explanation:
Biosystematics is concerned with studying the diversity of organisms and their comparative and evolutionary relationships. It uses information from several areas, including morphology, cytology, genetics, ecology and evolutionary history.

NEET Concept:
Systematics is broader than simple naming and classification because it also considers evolutionary relationships.

Explanation: Basidiomycetes produce basidiospores externally on basidia.

Explanation: In binomial nomenclature, the genus begins with a capital letter, the species name begins with a lowercase letter, and the complete scientific name is conventionally italicised when typed. The question database identifies this as a NEET 2019 PYQ.

Explanation:
In unicellular organisms, reproduction generally occurs by cell division. When one cell divides, it produces new individuals. Therefore, in such organisms, reproduction and growth can be closely associated.

The same question also tested two other important facts:

The biological species concept was given by Ernst Mayr.

Binomial nomenclature was not given by R.H. Whittaker; it is associated with Carolus Linnaeus.

Asked Again: The individual statements have been repeatedly tested in different forms.

Explanation:

Rhizopus → Bread mould. It commonly grows on moist bread and other organic materials.

Ustilago → Smut. Species of Ustilago cause smut diseases, particularly in cereal crops.

Puccinia → Rust. Puccinia species are important plant pathogens responsible for rust diseases.

Agaricus → Mushroom. Agaricus includes common edible mushrooms.

Therefore, the correct matching is A–3, B–4, C–2 and D–1,

Explanation:
Living organisms can sense and respond to changes in their environment. This ability is associated with consciousness. Living organisms possess receptors and mechanisms that allow them to perceive environmental stimuli and respond appropriately.

NEET Concept:
Consciousness and response to stimuli are important characteristics of living organisms.

Explanation:

Euglenoids → Mixotrophic; they can perform photosynthesis in light and obtain nutrition heterotrophically when required.

Dinoflagellates → Commonly photosynthetic.

Slime moulds → Saprophytic, feeding on decaying organic matter.

Plasmodium → Parasitic, living within a host and obtaining nutrients from it.

Explanation: Fungi are non-photosynthetic organisms and lack chlorophyll. Traditional classification focuses on mycelial characteristics and reproductive structures, particularly spores.

Explanation:
According to Robert May's estimate discussed in NCERT, the global species diversity is approximately 7 million. Only a fraction of the total number of species has been scientifically described.

NEET Concept:
Remember:

Estimated global species diversity ≈ 7 million

Explanation:
As we move downward through the hierarchy, the number of common characteristics generally increases.

Kingdom → Phylum → Class → Order → Family → Genus → Species

Species is the lowest principal category and therefore contains organisms with the greatest similarity.

Explanation:
Taxonomy traditionally includes identification, nomenclature and classification. Systematics has a broader perspective and attempts to understand diversity and evolutionary relationships among organisms.

Explanation:
The housefly belongs to the family Muscidae.

Its classification includes:

Kingdom — Animalia

Phylum — Arthropoda

Class — Insecta

Order — Diptera

Family — Muscidae

Genus — Musca

Species — Musca domestica

The other insects belong to different families.

Answer: B. Generic name and specific epithet

Explanation:
The binomial name consists of two components:

Generic name + Specific epithet

Example:

Homo sapiens

Homo = generic name

sapiens = specific epithet

The system is associated with Carolus Linnaeus.

Explanation:
Ascending order means moving from the lowest/smallest category to the highest/largest category.

Species → Genus → Family → Order → Class → Phylum → Kingdom

The reverse is the descending order.

Explanation:
The standard taxonomic hierarchy for animals is:

Kingdom → Phylum → Class → Order → Family → Genus → Species

For plants, Division is commonly used instead of Phylum.

Explanation: Mycoplasma are exceptionally small and lack a cell wall. This is why the second statement is incorrect.

Explanation:
Living organisms possess metabolism, which includes all the biochemical reactions occurring inside their cells. Growth, reproduction and movement are not individually exclusive characteristics of living organisms. For example, non-living objects may increase in size by accumulation of material, and reproduction is not an essential characteristic of every individual organism.

NEET Concept:
Metabolism is one of the most important distinguishing features of living organisms.

Explanation: Prions are infectious protein particles associated with transmissible neurodegenerative disorders, including BSE and Creutzfeldt–Jakob disease.

Explanation:
Species is the basic and lowest principal taxonomic category. Other taxonomic categories are generally arranged around species.

Examples:

Mangifera indica — mango

Solanum tuberosum — potato

Panthera leo — lion

NEET Concept:
Species → Genus → Family → Order → Class → Phylum/Division → Kingdom

Explanation: Archaebacteria possess a distinctive cell-wall composition different from the typical peptidoglycan-containing wall of eubacteria.

Explanation:
The horse belongs to:

Kingdom — Animalia

Phylum — Chordata

Class — Mammalia

Order — Perissodactyla

Family — Equidae

Genus — Equus

Therefore, Perissodactyla is the order.

Explanation: Cilia are the characteristic locomotory structures of ciliates. Paramecium is a classic example.

Explanation: The progression begins with prokaryotic organisation in Monera, followed by unicellular eukaryotic organisation in Protista, then multicellular fungal organisation and finally the more complex tissue/organ organisation of plants and animals. The 2025 PYQ specifically tested this increasing-complexity concept.

Explanation: Cyanobacteria are bacteria capable of photosynthesis and do not possess chloroplasts.

Explanation: Archaebacteria possess a distinctive cell-wall composition and membrane chemistry. Their cell walls do not have the typical peptidoglycan characteristic of eubacteria.

Explanation:
Tomato and potato belong to different genera but the same family:

Tomato → Solanum

Potato → Solanum

Important correction: Modern accepted scientific treatment places both tomato and potato in the genus Solanum. Therefore, for the commonly used modern classification, their maximum similarity is at the genus level.

Because some older PYQ databases use older nomenclature/classification for tomato, this question should be handled carefully in an ebook. The underlying NEET concept is that the lower the taxonomic rank, the greater the similarity.

Explanation:
The scientific name of mango is:

Mangifera indica

When the authority is included, Linn. indicates Carolus Linnaeus.

Important formatting:

Mangifera → capitalised genus

indica → lowercase specific epithet

Both are italicised in print.

Explanation: Mycoplasma are wall-less bacteria. They possess a plasma membrane but lack the typical bacterial cell wall.

Explanation: Whittaker's classification considered cell structure, body organisation, mode of nutrition, reproduction and phylogenetic relationships.

Explanation: Viroids are much simpler than viruses and consist of small infectious RNA molecules without a protein coat.

Explanation:
Ernst Mayr is associated with the biological species concept. Under this concept, a species is generally a group of naturally interbreeding populations that are reproductively isolated from other such groups and produce fertile offspring.

Explanation:
Scientific names follow internationally accepted nomenclatural conventions and are generally Latin or Latinised in form.

In a binomial:

First word = Genus
Second word = Specific epithet

Example:

Homo sapiens

Homo → genus

sapiens → specific epithet

Explanation: Bacteria, cyanobacteria and Mycoplasma are prokaryotic, whereas protozoans are eukaryotic organisms.