Part 7 — Critical & Complex NEET-level Questions (Q.151–175)

Part 7 — Critical & Complex NEET-level Questions (Q.151–175)

Q151. Which of the following statements about protostome and deuterostome development is FALSE?

A) In protostomes, cleavage is often spiral and determinate; blastopore becomes mouth
B) In deuterostomes, cleavage is radial and indeterminate; blastopore becomes anus
C) All animals with radial cleavage are deuterostomes without exception
D) Some exceptions and variations exist in developmental patterns across taxa
Answer: C
Explanation:
A/B) True generalizations.
C) False — though radial cleavage is typical of deuterostomes, biology shows exceptions and variability; some protostomes show radial patterns.
D) True.

Q152. Which of the following correctly pairs a parasite with its intermediate host?

A) Taenia solium — snails
B) Schistosoma — freshwater snails; intermediate host is snail where miracidia develop into sporocysts/rediae/cercariae
C) Wuchereria — mosquito (vector for filarial nematodes, yes) but intermediate host terminology can vary; correct pairing for Schistosoma is snail
D) Ascaris — fish
Answer: B
Explanation:
A) Taenia has pig (intermediate) for T. solium.
B) Correct — schistosomes use snail.
C) Wuchereria — transmitted by mosquitoes but definitive host is human; mosquito is vector.
D) Ascaris intermediate host not fish; direct egg ingestion.

Q153. Which of these is an example of convergent evolution?

A) Wings of insects, birds and bats — independent evolution of flight structures in unrelated lineages
B) Homologous forelimbs of mammals all identical in function
C) Notochord in all chordates deriving from same embryonic structure only
D) Segmentation in annelids and chordates always homologous
Answer: A
Explanation:
A) Correct — similar function/appearance due to similar selective pressures, not common ancestry.
B/C/D) Misinterpret homologous vs analogous structures.

Q154. Assertion (A): Arthropods and annelids are both segmented. Reason (R): Both groups evolved segmentation from a common segmented ancestor. Choose correct option.

A) Both A and R true and R explains A
B) Both true but R not correct explanation (segmentation may be convergent)
C) A true R false
D) A false R true
Answer: B
Explanation:
A) Not fully supported; segmentation could be homologous or convergent.
B) Correct — both groups are segmented, but segmentation probably evolved independently (convergent) or is partially homologous; consensus leans toward convergent evolution for complex segmentation.

Q155. Which of the following animal groups displays indeterminate (regulative) cleavage in embryogenesis?

A) Many deuterostomes (e.g., echinoderms, chordates) show radial and indeterminate cleavage allowing embryonic cells to form complete embryos if separated
B) Protostomes only
C) All protostomes and deuterostomes show determinate cleavage
D) No animals show indeterminate cleavage
Answer: A
Explanation:
B/C/D) False.
A) Correct — indeterminate cleavage characteristic of many deuterostomes.

Q156. Which is an example of paedomorphosis (retention of juvenile traits in adult stage) in chordates?

A) Adult frog development only
B) Axolotl (a salamander) retains larval gills and aquatic lifestyle at sexual maturity, an example of paedomorphosis
C) Bird feathers
D) Mammalian lactation
Answer: B
Explanation:
A/C/D) Not paedomorphosis.
B) Correct — axolotl is classic paedomorphic salamander.

Q157. Among invertebrates, the presence of neural crest-like cells has been reported in:

A) Only vertebrates
B) Some hemichordates and cephalochordates show cell populations with some neural crest-like properties; this helps understand vertebrate evolution — but canonical neural crest is vertebrate innovation
C) Sponges
D) cnidarians
Answer: B
Explanation:
A) Historically thought so but research indicates neural crest-like cells in related deuterostomes.
B) Correct nuance for NEET-level evolutionary insight.
C/D) Not correct.

Q158. In which case would the taxon “Pisces” be considered paraphyletic?

A) If fishes include all descendants including tetrapods like amphibians, reptiles, birds, mammals — then “Pisces” is not a clade because it excludes tetrapods that descended from within fish lineages; hence paraphyletic if defined traditionally excluding tetrapods
B) If fishes include birds
C) If fishes are defined by presence of legs
D) If fishes include all animals
Answer: A
Explanation:
B/C/D) Conceptual errors.
A) Correct — “Pisces” traditionally excludes tetrapods even though tetrapods evolved from fish ancestors; this makes it paraphyletic.

Q159. Which of the following demonstrates adaptive radiation?

A) Darwin’s finches evolving multiple beak types from a common ancestor in Galápagos islands adapting to different niches; similarly, cichlid fishes in African lakes
B) Single species unchanged forever
C) Convergent evolution examples only
D) Random genetic drift only
Answer: A
Explanation:
B/C/D) Not adaptive radiation.
A) Correct — diversification into various forms adapted to different ecological niches.

Q160. In classification, which is the correct sequence from broad to specific?

A) Species → Genus → Family → Order → Class → Phylum → Kingdom → Domain
B) Domain → Kingdom → Phylum → Class → Order → Family → Genus → Species
C) Kingdom → Species → Domain → Family …
D) Genus → Domain → Family → Species
Answer: B
Explanation:
A/C/D) Incorrect ordering.
B) Correct — standard hierarchical taxonomy.

Q161. Which of the following best describes the evolutionary significance of the notochord?

A) Structural support in all chordates; in vertebrates, replaced or supplemented by vertebral column, but it is a key synapomorphy of phylum Chordata
B) Found only in invertebrates
C) Functions in respiration only
D) Is the same as stomochord in hemichordates
Answer: A
Explanation:
B/C/D) Incorrect.
A) Correct.

Q162. Which of the following organisms shows hermaphroditism?

A) Most mammals only
B) Many invertebrates (e.g., earthworms are monoecious/hermaphroditic; many gastropods, platyhelminths) and some fishes are sequential hermaphrodites
C) All fishes are hermaphrodites
D) All birds are hermaphrodites
Answer: B
Explanation:
A/C/D) Wrong.
B) Correct — hermaphroditism common in invertebrates and some fishes.

Q163. Which is the main evolutionary advantage of the amniotic egg?

A) Dependence on water for development increases
B) Allows embryonic development in terrestrial environment by providing protective membranes and nutrient storage, freeing reproduction from water bodies
C) Reduces gas exchange capability
D) Decreases survival on land
Answer: B
Explanation:
A/C/D) Opposite effects.
B) Correct — amniotic egg is key for terrestrial reproduction.

Q164. Which of these diseases involves a protozoan parasite with vector-borne transmission by Anopheles mosquitoes?

A) Malaria (Plasmodium spp.) transmitted by female Anopheles mosquitoes — a protozoan disease of high medical relevance
B) Bacterial cholera
C) Viral influenza
D) Helminthic filariasis
Answer: A
Explanation:
B/C/D) Different etiologies.
A) Correct.

Q165. Which of the following is an example of ectoparasite?

A) Plasmodium (endoparasite)
B) Tick (Arachnida) which feeds on the surface/externally on host blood — ectoparasite
C) Taenia (internal)
D) Malaria parasite inside RBCs
Answer: B
Explanation:
A/C/D) Endoparasites or internal.
B) Correct — ticks attach externally.

Q166. Which evolutionary novelty allowed insects to become the most diverse terrestrial animal group?

A) Development of jointed exoskeleton only
B) Small size, flight (wings), metamorphosis, and exploitation of varied niches, and efficient respiratory and excretory systems; wings in particular opened aerial niche
C) Possession of notochord
D) Lungs similar to mammals
Answer: B
Explanation:
A/C/D) Incomplete/incorrect.
B) Correct — combination of features enabled insect success.

Q167. Which of the following is correct about vertebrate kidneys?

A) Kidneys excrete nitrogenous waste and regulate water-salt balance; adaptations differ (nephrons, loops of Henle in mammals concentrate urine)
B) Invertebrates have nephrons identical to mammals
C) All vertebrate kidneys are identical across taxa
D) Kidneys produce gametes
Answer: A
Explanation:
B/C/D) Not correct.
A) Correct.

Q168. Which of these animal groups has decentralized nervous system with nerve net?

A) Cnidaria (e.g., hydra, jellyfish) have diffuse nerve net without central brain
B) Vertebrates
C) Arthropods
D) Molluscs only
Answer: A
Explanation:
B/C/D) Centralised nervous systems.
A) Correct.

Q169. Which of the following statements about segmentation is correct?

A) Segmentation is always homologous across annelids, arthropods, and chordates
B) Segmentation (repeated body units) occurs in annelids, arthropods, and chordates; homology is debated — some segments may be convergent adaptations for locomotion and body plan organization
C) Segmentation occurs only in vertebrates
D) Segmentation is absent in all animals
Answer: B
Explanation:
A) Homology debated; B is nuanced correct.
C/D) False.

Q170. Which of the following animals displays direct development (no larval stage)?

A) Many reptiles and birds hatch as mini-adults (direct development); many amphibians show indirect development with tadpole larva
B) All fishes only have larval stages
C) All amphibians have direct development
D) All invertebrates have indirect development
Answer: A
Explanation:
B/C/D) Overgeneralizations.
A) Correct — direct vs indirect varies by group and species.

Q171. Which of the following best exemplifies a keystone species concept in ecology?

A) A species with a disproportionately large effect on community structure, e.g., sea stars (Pisaster) controlling mussel populations, removal causes major shifts
B) A species with no ecological role
C) An organism with no predators
D) All species are equivalent in ecosystem impact
Answer: A
Explanation:
B/C/D) Incorrect.
A) Correct — keystone species maintain ecosystem balance.

Q172. Which of the following animal groups exhibits metameric segmentation with septa?

A) Annelida (earthworms) have true segmentation with septa dividing coelom into compartments
B) Arthropoda have exoskeleton segmentation but septa not like annelids
C) Platyhelminthes lack true metameric septation
D) All of above combined options considered, best single answer: A
Answer: A
Explanation:
B/C) True statements but they do not have septate coelom like annelids.
A) Correct.

Q173. Which of the following is true about bird respiration?

A) Tidal flow similar to mammals only
B) Unidirectional airflow through parabronchi in lungs aided by air sacs ensures continuous air flow and efficient gas exchange even during exhalation — adaptation for high metabolic demands of flight
C) Birds respire through gills
D) Birds do not require oxygen during flight
Answer: B
Explanation:
A/C/D) Incorrect.
B) Correct.

Q174. Invertebrate chordates (cephalochordates) feed by:

A) Predation on fish
B) Filter feeding using buccal cirri and pharyngeal slits with mucous trapping particles; cilia-driven water flow draws food into pharynx
C) Photosynthesis
D) Absorbing nutrients across body surface only
Answer: B
Explanation:
A/C/D) Not correct.
B) Correct.

Q175. Which of the following phyla is most closely related to chordates based on molecular and developmental data?

A) Arthropoda
B) Echinodermata and Hemichordata as fellow deuterostomes are closer to chordates than protostomes like arthropods and molluscs
C) Cnidaria
D) Porifera
Answer: B
Explanation:
A/C/D) Distantly related.
B) Correct — echinoderms and hemichordates form deuterostome clade with chordates. (more…)