Biological Classification
5 solved NEET Biology previous year questions on Biological Classification, each with the correct answer and a full explanation.
Q1
BGA (blue green algae) are included in which of the following groups?
✓ Correct answer: b) Prokaryotes
Explanation✅ Correct Answer: B) Prokaryotes Explanation: BGA (Blue-Green Algae), also known as Cyanobacteria, are prokaryotic organisms.They lack a true nucleus and are classified as bacteria.Despite performing photosynthesis, similar to plants, they are still classified as prokaryotes because they lack membrane-bound organelles.Why other options are incorrect?(A) Deuteromycetes – These are fungi and are not related to cyanobacteria.(C) Protista – Cyanobacteria are not eukaryotes like Protista; they are prokaryotic.(D) Fungi – Fungi are separate from bacteria, and cyanobacteria are not fungi.Thus, BGA (Blue-Green Algae) are included in the group of Prokaryotes.
Q2
Maximum nutritional diversity is found in the group
✓ Correct answer: c) monera
Explanation✅ Correct Answer: C) Monera Explanation: Kingdom Monera (Bacteria) exhibits the maximum nutritional diversity because bacteria have evolved multiple modes of obtaining nutrition.They can be:1. Autotrophic Bacteria (Make their own food) Photoautotrophic – Use sunlight for energy (e.g., Cyanobacteria like Anabaena and Nostoc).Chemoautotrophic – Use chemical energy for synthesis (e.g., Nitrosomonas, Nitrobacter).2. Heterotrophic Bacteria (Depend on other sources for food) Saprophytic – Decomposers that break down dead organic matter (e.g., Pseudomonas).Parasitic – Live inside a host and cause diseases (e.g., Mycobacterium tuberculosis).Symbiotic – Live in mutual association with plants/animals (e.g., Rhizobium in leguminous plants).Why Other Options Are Incorrect? ❌ A) Fungi – Mostly heterotrophic, either saprophytic or parasitic. ❌ B) Animalia – Strictly heterotrophic, consuming other organisms. ❌ D) Plantae – Mostly photoautotrophic, using photosynthesis.Thus, Monera (Bacteria) has the greatest diversity in nutritional modes!
Q3
Which one of the following is not a criterion for classification of fungi?
✓ Correct answer: c) Mode of nutrition
ExplanationThe morphology of the mycelium, mode of spore formation and fruiting bodies form the basis for the division of the kingdom into various classes.However, their mode of nutrition (all are heterotrophic — saprophytic, parasitic, or symbiotic) is not used as a major criterion for fungal classification because it does not vary enough to distinguish different fungal groups.
Q4
Ciliates differ from all other protozoans in
✓ Correct answer: d) having two types of nuclei
ExplanationCiliates, like Paramecium, are unique among protozoans because they possess two nuclei: a macronucleus that controls metabolic and vegetative functions, and a micronucleus responsible for reproduction during conjugation.Other protozoans do not have this dual nuclear system.Features like flagella, pseudopodia, or contractile vacuoles are present in various protozoans, so they are not unique to ciliates.
Q5
Which among the following is not a prokaryote?
✓ Correct answer: a) Saccharomyces
ExplanationThe organism that is not a prokaryote is: Saccharomyces - A unicellular fungus (Kingdom Fungi) (Eukaryotic) Mycobacterium - Bacterium (Prokaryotic) Nostoc - Cyanobacterium (Prokaryotic) Oscillatoria - Cyanobacterium (Prokaryotic) Correct Answer: A) Saccharomyces
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