ANIMAL KINGDOM MCQs for NEET UG BIOLOGY — Easy

1 Easy

1 of 63

Analyzing +4 | -1

Assertion: Metagenesis in Obelia is equivalent to
alternation of generation in plant
Reason: Polyp is haploid and medusa phase is diploid in
Obelia

View answer and explanation

Correct option: D

If both the assertion and reason are false

Option D (If both the assertion and reason are false) is correct because metagenesis in Obelia is not equivalent to alternation of generation in plants, and both polyp and medusa are diploid.

Solution approach

Correct Answer + Core Reason: If both the assertion and reason are false. Metagenesis and alternation of generation are different, and both polyp and medusa are diploid.

Step-by-Step Solution:

Step 1: Evaluate the Assertion.

Step 2: Assertion: Metagenesis in Obelia is equivalent to alternation of generation in plant: False. Metagenesis is the alternation of asexual (polyp) and sexual (medusa) phases, while alternation of generation in plants involves alternation of haploid and diploid phases.

Step 3: Evaluate the Reason.

Step 4: Reason: Polyp is haploid and medusa phase is diploid in Obelia: False. Both polyp and medusa are diploid in Obelia.

Why other options are wrong:
- Option A: Both assertion and reason are false.
- Option B: Both assertion and reason are false.
- Option C: Both assertion and reason are false.

Key Concepts:
- Metagenesis in Obelia
- Alternation of generation in plants

Memory Aids:
- Remember that metagenesis involves alternation of body forms, while alternation of generation involves alternation of ploidy levels.

Quick Tips:
- Distinguish between metagenesis and alternation of generation.

2 Easy

2 of 63

Understanding +4 | -1

In tissue level of organisation the

View answer and explanation

Correct option: C

Cells performing the same function are arranged into groups

Option C (Cells performing the same function are arranged into groups) is correct because the tissue level of organization is defined by cells with similar structure and function being organized into groups called tissues.

Solution approach

Correct Answer + Core Reason: Cells performing the same function are arranged into groups. This defines the tissue level of organization.

Step-by-Step Solution:

Step 1: Define tissue level of organization. In the tissue level of organization, cells with similar structure and function are organized into tissues.

Step 2: Consider each option:
- Cells are arranged as loose cell aggregate: This describes cellular level of organization.
- Tissues are grouped to form organs: This describes organ level of organization.
- Cells performing the same function are arranged into groups: This accurately describes tissue level of organization.
- Tissues are grouped to form systems: This describes organ system level of organization.

Step 3: Identify the correct description. The correct description of the tissue level of organization is that cells performing the same function are arranged into groups.

Why other options are wrong:
- Option A: Cells are arranged as loose cell aggregate: This describes the cellular level of organization, not the tissue level.
- Option B: Tissues are grouped to form organs: This describes the organ level of organization, not the tissue level.
- Option D: Tissues are grouped to form systems: This describes the organ system level of organization, not the tissue level.

Key Concepts:
- Cellular Level of Organization
- Tissue Level of Organization
- Organ Level of Organization
- Organ System Level of Organization

Memory Aids:
- Tissue: Think "Together" - cells working together.

Quick Tips:
- Know the different levels of organization in animals.

3 Easy

3 of 63

Understanding +4 | -1

Select the correct matching of animal its symmetry and type of body cavity

View answer and explanation

Correct option: D

Animal - Earth Worm, Symmetry - Bilateral , Body Cavity - Schizocoelom

Option D is correct because Earthworms exhibit bilateral symmetry and possess a schizocoelom, a true coelom formed by splitting of the mesoderm.

Solution approach

Correct Answer + Core Reason: Animal - Earth Worm, Symmetry - Bilateral , Body Cavity - Schizocoelom. Earthworms have bilateral symmetry and a schizocoelom.

Step-by-Step Solution:

Step 1: Identify the characteristics of each animal.

Step 2: Jellyfish have radial symmetry and lack a true coelom (acoelomate).

Step 3: Starfish (adults) have radial symmetry, not bilateral. They are coelomate.

Step 4: Tapeworms have bilateral symmetry and are acoelomate.

Step 5: Earthworms have bilateral symmetry and a schizocoelom (a true coelom).

Why other options are wrong:
- Option A: Jellyfish have radial symmetry, not bilateral, and they are acoelomate, not pseudocoelomate.
- Option B: Starfish have radial symmetry (as adults), not bilateral. They are coelomate, not pseudocoelomate.
- Option C: Tapeworms have bilateral symmetry and are acoelomate, but they do not have biradial symmetry.

Key Concepts:
- Animal symmetry (radial, bilateral, biradial)
- Body cavity types (acoelomate, pseudocoelomate, coelomate)
- Animal classification

Memory Aids:
- "Triploblastic Coelomates are more complex than Diploblastic Acoelomates".

Quick Tips:
- Remember the key characteristics of each phylum to quickly eliminate incorrect options.

4 Easy

4 of 63

Remembering +4 | -1

Bioluminescence is well marked in

View answer and explanation

Correct option: B

Ctenophores

Option B (Ctenophores) is correct because bioluminescence is a well-marked characteristic of Ctenophores, also known as comb jellies.

Solution approach

Correct Answer + Core Reason: Ctenophores. Bioluminescence is a prominent feature in Ctenophores.

Step-by-Step Solution:

Step 1: Recall the characteristics of different invertebrate phyla.

Step 2: Remember that Ctenophores are known for their bioluminescence, which is produced by photoproteins.

Step 3: Consider other phyla and their bioluminescent capabilities, if any.

Step 4: Conclude that bioluminescence is most well-marked in Ctenophores.

Why other options are wrong:
- Option A: Flatworms: Flatworms are generally not known for bioluminescence.
- Option C: Cnidarians: While some Cnidarians exhibit bioluminescence, it is not as well-marked as in Ctenophores.
- Option D: Aschelminthes: Aschelminthes (now a deprecated phylum) are not particularly known for bioluminescence.

Key Concepts:
- Bioluminescence
- Characteristics of Phylum Ctenophora
- Characteristics of other invertebrate phyla

Memory Aids:
- Ctenophores = Glowing Comb Jellies (think of the light from the comb plates)

Quick Tips:
- Remember key characteristics associated with each phylum to answer such questions effectively.

5 Easy

5 of 63

Understanding +4 | -1

Which of the following is not a dioecious organism?

View answer and explanation

Correct option: D

Ctenoplana

Option D (Ctenoplana) is correct because Ctenoplana is typically hermaphroditic, meaning it possesses both male and female reproductive organs, while Ascaris, Octopus, and Wuchereria are dioecious (separate sexes).

Solution approach

Correct Answer + Core Reason: Ctenoplana. Ctenoplana is hermaphroditic, not dioecious.

Step-by-Step Solution:

Step 1: Define the terms dioecious and hermaphroditic.

Step 2: Recall the reproductive strategies of the organisms listed: Ascaris, Octopus, Wuchereria, and Ctenoplana.

Step 3: Identify that Ctenoplana is typically hermaphroditic, while the others are dioecious.

Why other options are wrong:
- Option A: Ascaris is dioecious.
- Option B: Octopus is dioecious.
- Option C: Wuchereria is dioecious.

Key Concepts:
- Reproductive strategies
- Dioecious
- Hermaphroditic

Memory Aids:
- Remember that \'dioecious\' means \'two houses\' (separate sexes), while \'hermaphroditic\' has both sexes in one \'house.\'

Quick Tips:
- Know the reproductive strategies of common animal groups.

6 Easy

6 of 63

Remembering +4 | -1

Ctenophora shows affinities with

View answer and explanation

Correct option: A

Cnidaria

Option A (Cnidaria) is correct because Ctenophora shares characteristics like radial symmetry and diploblastic organization with Cnidaria, indicating evolutionary affinities.

Solution approach

Correct Answer + Core Reason: Cnidaria. Ctenophora shares radial symmetry and diploblastic organization with Cnidaria.

Step-by-Step Solution:

Step 1: Identify the key characteristics of Ctenophora: radial symmetry, diploblastic organization, and presence of colloblasts.

Step 2: Compare these characteristics with those of other phyla.

Step 3: Recognize that Cnidaria also exhibits radial symmetry and diploblastic organization.

Step 4: Conclude that Ctenophora shares affinities with Cnidaria due to these shared characteristics.

Why other options are wrong:
- Option B: Aschelminthes are pseudocoelomates and have a different body plan.
- Option C: Cephalopoda are mollusks with bilateral symmetry and a complex nervous system, unlike Ctenophora.
- Option D: Turbellaria are flatworms with bilateral symmetry and a triploblastic organization.

Key Concepts:
- Animal classification
- Radial symmetry
- Diploblastic organization
- Evolutionary affinities

Memory Aids:
- Remember that both Ctenophora and Cnidaria are radially symmetrical and diploblastic.

Quick Tips:
- Focus on the fundamental body plan and symmetry when determining evolutionary relationships.

7 Easy

7 of 63

Understanding +4 | -1

Select the incorrect match.

View answer and explanation

Correct option: B

Pleurobrachia – Possesses four external rows of ciliated comb plates

Option B is the incorrect match because Pleurobrachia possesses eight external rows of ciliated comb plates, not four.

Solution approach

Correct Answer + Core Reason: Pleurobrachia – Possesses four external rows of ciliated comb plates. Pleurobrachia has eight rows of ciliated comb plates.

Step-by-Step Solution:
Step 1: Identify the characteristics of each organism listed.
Step 2: Ctenoplana exhibits bioluminescence, Pleurobrachia has eight rows of ciliated comb plates, Taenia has hooks and suckers, and Fasciola has flame cells for osmoregulation and excretion.
Step 3: Compare the given characteristics with the actual characteristics of each organism.

Why other options are wrong:
- Option A: Ctenoplana does exhibit bioluminescence, so this match is correct.
- Option C: Taenia does exhibit hooks and suckers for attachment, so this match is correct.
- Option D: Fasciola does exhibit flame cells for osmoregulation and excretion, so this match is correct.

Key Concepts:
- Characteristics of different organisms in the animal kingdom.
- Bioluminescence, ciliated comb plates, hooks and suckers, flame cells.

Memory Aids:
- Remember that Ctenophores (like Pleurobrachia) use ciliated comb plates for locomotion.

Quick Tips:
- When matching organisms with their characteristics, carefully consider each feature and its association with the correct organism.

8 Easy

8 of 63

Remembering +4 | -1

Adult annelids have symmetry similar to that of

View answer and explanation

Correct option: D

Chordates

Option D (Chordates) is correct because adult annelids exhibit bilateral symmetry and metameric segmentation, similar to chordates.

Solution approach

Correct Answer + Core Reason: Chordates. Adult annelids exhibit bilateral symmetry similar to chordates.

Step-by-Step Solution:

Step 1: Recall the symmetry of annelids. Adult annelids have bilateral symmetry and are segmented (metameric segmentation).

Step 2: Consider the symmetry of each option:
- Adult coelenterate: Radial symmetry.
- Most of sponges: Asymmetry.
- Adult echinodermates: Pentaradial symmetry.
- Chordates: Bilateral symmetry.

Step 3: Identify the phylum with similar symmetry. Chordates also have bilateral symmetry.

Why other options are wrong:
- Option A: Adult coelenterate: Coelenterates have radial symmetry, which is different from the bilateral symmetry of annelids.
- Option B: Most of sponges: Sponges are asymmetrical, unlike annelids.
- Option C: Adult echinodermates: Adult echinoderms have pentaradial symmetry, which is different from the bilateral symmetry of annelids.

Key Concepts:
- Bilateral Symmetry
- Radial Symmetry
- Asymmetry
- Animal Phyla

Memory Aids:
- Annelids and Chordates: Both have bilateral symmetry.

Quick Tips:
- Know the symmetry types for major animal phyla.

9 Easy

9 of 63

Remembering +4 | -1

Which of the following cell types is capable of giving rise to other cell types in sponges?

View answer and explanation

Correct option: D

Archaeocytes

Option D (Archaeocytes) is correct because archaeocytes are totipotent cells in sponges that can differentiate into other cell types.

Solution approach

Correct Answer + Core Reason: Archaeocytes. They are totipotent cells that can differentiate into other cell types.

Step-by-Step Solution:

Step 1: Define each cell type in sponges.

Step 2: Thesocytes - Storage cells for reserve food.

Step 3: Pinacocytes - Outer layer of cells in sponges.

Step 4: Cnidocytes - Stinging cells (found in Cnidarians, not sponges).

Step 5: Archaeocytes - Totipotent cells that can differentiate into other cell types (e.g., sclerocytes, spongocytes, collencytes).

Step 6: Archaeocytes are the cells capable of giving rise to other cell types in sponges.

Why other options are wrong:
- Option A: Thesocytes - These cells store food reserves, but do not differentiate into other cell types.
- Option B: Pinacocytes - These cells form the outer layer of the sponge and do not differentiate into other cell types.
- Option C: Cnidocytes - These cells are stinging cells found in Cnidarians, not sponges.

Key Concepts:
- Sponge Cell Types
- Totipotency
- Cell Differentiation

Memory Aids:
- Archaeocytes: "Archaeo" suggests "ancient" or "original," implying they are the source of other cells.

Quick Tips:
- Remember the function of each cell type in sponges.

10 Easy

10 of 63

Remembering +4 | -1

Trichocyst and nematocysts are meant for

View answer and explanation

Correct option: A

Defence

Option A (Defence) is correct because trichocysts and nematocysts are specialized organelles used by cnidarians for defense, prey capture, and attachment.

Solution approach

Correct Answer + Core Reason: Defence. Trichocysts and nematocysts are used for defence.

Step-by-Step Solution:

Step 1: Define trichocysts and nematocysts: These are specialized organelles found in cnidocytes (stinging cells) of cnidarians.

Step 2: Describe their function: They are primarily used for:
- Defence against predators
- Capture of prey
- Attachment to substrates

Step 3: Consider other options:
- Nutrition: While nematocysts aid in prey capture, the primary function is not direct nutrition.
- Respiration: These structures are not involved in respiration.
- Excretion: These structures are not involved in excretion.

Step 4: Conclude that the primary function is defence.

Why other options are wrong:
- Option B: While nematocysts aid in prey capture, the primary function is not direct nutrition.
- Option C: Trichocysts and nematocysts are not involved in respiration.
- Option D: Trichocysts and nematocysts are not involved in excretion.

Key Concepts:
- Cnidarian biology
- Cnidocytes
- Nematocysts
- Defence mechanisms

Memory Aids:
- Nematocysts = Stinging = Defence

Quick Tips:
- Remember the function of nematocysts in cnidarians.
- Associate nematocysts with stinging and defence.

11 Easy

11 of 63

Remembering +4 | -1

The internal buds of freshwater sponges are otherwise called.

View answer and explanation

Correct option: B

Gemmule

Option B (Gemmule) is correct because gemmules are internal buds found in freshwater sponges, used for asexual reproduction and survival in harsh conditions.

Solution approach

Correct Answer + Core Reason: Gemmule. Gemmules are internal buds characteristic of freshwater sponges.

Step-by-Step Solution:

Step 1: Recall the asexual reproductive structures in sponges.

Step 2: Remember that freshwater sponges form internal buds called gemmules, which are resistant to harsh environmental conditions.

Step 3: Consider other structures found in sponges and their functions.

Step 4: Conclude that gemmules are the internal buds of freshwater sponges.

Why other options are wrong:
- Option A: Choanocyte: Choanocytes are flagellated collar cells that line the interior of sponges and are involved in filter feeding, not internal bud formation.
- Option C: Osculum: Osculum is a large opening in sponges through which water exits, not an internal bud.
- Option D: Blastula: Blastula is an early embryonic stage in animal development, not a specific structure in sponges for asexual reproduction.

Key Concepts:
- Asexual reproduction in sponges
- Gemmules
- Sponge anatomy

Memory Aids:
- Gemmules = Germinating modules (internal buds)

Quick Tips:
- Remember the different structures in sponges and their respective functions.

12 Easy

12 of 63

Analyzing +4 | -1

Which of the following group is odd one out of the basis of coelomic cavity?

View answer and explanation

Correct option: B

Nereis, Asterias, Ancylostoma

Option B (Nereis, Asterias, Ancylostoma) is the odd one out because Nereis and Asterias are coelomates, while Ancylostoma is a pseudocoelomate.

Solution approach

Correct Answer + Core Reason: Nereis, Asterias, Ancylostoma. Nereis and Asterias are coelomates, while Ancylostoma is a pseudocoelomate.

Step-by-Step Solution:

Step 1: Analyze option A: Asterias (Echinodermata), Octopus (Mollusca), and Periplaneta (Arthropoda) are all coelomates.

Step 2: Analyze option B: Nereis (Annelida) and Asterias (Echinodermata) are coelomates, but Ancylostoma (Aschelminthes) is a pseudocoelomate. Therefore, this group is the odd one out.

Step 3: Analyze option C: Pheretima (Annelida), Periplaneta (Arthropoda), and Locusta (Arthropoda) are all coelomates.

Step 4: Analyze option D: Ophiura (Echinodermata), Aplysia (Mollusca), and Apis (Arthropoda) are all coelomates.

Step 5: Identify the odd one out: Option B contains a pseudocoelomate (Ancylostoma) while the others are all coelomates.

Why other options are wrong:
- Option A: All three organisms are coelomates.
- Option C: All three organisms are coelomates.
- Option D: All three organisms are coelomates.

Key Concepts:
- Coelomic cavity types: coelomate, pseudocoelomate, acoelomate
- Animal classification

Memory Aids:
- Coelomates: Annelida, Mollusca, Arthropoda, Echinodermata, Chordata
- Pseudocoelomates: Aschelminthes (Nematoda)

Quick Tips:
- Remember the phyla associated with each type of coelomic cavity.

13 Easy

13 of 63

Remembering +4 | -1

Cavity of coelenterates is called

View answer and explanation

Correct option: A

Coelenterons

Option A (Coelenterons) is correct because the cavity of coelenterates is specifically called the coelenteron, serving as both a digestive and circulatory cavity.

Solution approach

Correct Answer + Core Reason: Coelenterons. The cavity of coelenterates is called coelenterons.

Step-by-Step Solution:

Step 1: Identify the phylum: The question refers to coelenterates (also known as cnidarians).

Step 2: Recall the defining characteristics of coelenterates: They possess a central body cavity.

Step 3: Define Coelenteron: This cavity is called the coelenteron or gastrovascular cavity.

Step 4: Conclusion: Therefore, the cavity of coelenterates is called coelenterons.

Why other options are wrong:
- Option B: Coelom is a body cavity found in more complex animals (e.g., annelids, mollusks, arthropods, chordates), not coelenterates.
- Option C: Cavity is a general term and not specific to coelenterates; the specific term is coelenteron.
- Option D: This option is incorrect because option A is the correct answer.

Key Concepts:
- Coelenterates (Cnidarians)
- Coelenteron (Gastrovascular cavity)
- Animal Kingdom Classification

Memory Aids:
- Coelenterates = Coelenteron (helps associate the phylum with its cavity)

Quick Tips:
- Remember that coelenterates are simple animals with a single opening for both ingestion and egestion into the coelenteron.

14 Easy

14 of 63

Understanding +4 | -1

Choose the false option

View answer and explanation

Correct option: D

Annelid-Pseudocoelomate

Option D (Annelid-Pseudocoelomate) is correct because Annelids are coelomate, not pseudocoelomate.

Solution approach

Correct Answer + Core Reason: Annelid-Pseudocoelomate. Annelids are coelomate animals, possessing a true coelom, not a pseudocoelom.

Step-by-Step Solution:

Step 1: Define the terms:
- Asymmetrical: Lacking symmetry.
- Diploblastic: Having two germ layers (ectoderm and endoderm).
- Radial symmetry: Symmetry around a central axis.
- Non-chordates: Animals without a notochord.
- Chordates: Animals with a notochord.
- Pseudocoelomate: Having a body cavity that is not completely lined by mesoderm.
- Coelomate: Having a true coelom, a body cavity completely lined by mesoderm.

Step 2: Analyze each option:
- A. Amoeba-Asymmetrical: Correct, Amoeba lacks a defined symmetry.
- B. Coelenterates-Diploblastic, radial symmetry, non-chordates: Correct, Coelenterates (Cnidarians) are diploblastic, radially symmetrical, and non-chordates.
- C. Chordates-Petromyzon, Ornithorhynchus, Equus: Correct, these are all chordates (Petromyzon - lamprey, Ornithorhynchus - platypus, Equus - horse).
- D. Annelid-Pseudocoelomate: Incorrect, Annelids are coelomate, not pseudocoelomate.

Step 3: Conclusion: The false statement is that Annelids are pseudocoelomate.

Why other options are wrong:
- Option A: Amoeba is indeed asymmetrical, making this statement true.
- Option B: Coelenterates (Cnidarians) are diploblastic, radially symmetrical, and non-chordates, making this statement true.
- Option C: Petromyzon, Ornithorhynchus, and Equus are all chordates, making this statement true.

Key Concepts:
- Animal Symmetry
- Germ Layers
- Coelom Types
- Chordate vs. Non-chordate

Memory Aids:
- Remember the coelom types: acoelomate (no coelom), pseudocoelomate (false coelom), and coelomate (true coelom).

Quick Tips:
- Know the key characteristics of each major animal phylum, including their symmetry, germ layers, and coelom type.

15 Easy

15 of 63

Understanding +4 | -1

Sycon belongs to a group of animals which are best described as

View answer and explanation

Correct option: C

Multicellular. Without any tissue organization

Option C (Multicellular. Without any tissue organization) is correct because sponges are multicellular organisms with a cellular level of organization, lacking true tissues.

Solution approach

Correct Answer + Core Reason: Multicellular. Without any tissue organization. Sponges have a cellular level of organization and lack true tissues.

Step-by-Step Solution:
Step 1: Recall the levels of organization in animals.
Step 2: Cellular level: Cells are loosely organized and do not form true tissues.
Step 3: Tissue level: Cells are organized into tissues with specific functions.
Step 4: Sponges have a cellular level of organization, meaning their cells are not organized into true tissues.

Why other options are wrong:
- Option A: Sponges do not have tissue organization.
- Option B: Sponges are multicellular.
- Option C: Sponges are multicellular without tissue organization.
- Option D: Sponges do not have tissue organization or a gastrovascular system.

Key Concepts:
- Levels of organization: Cellular, Tissue, Organ, Organ system
- Sponge characteristics

Memory Aids:
- Sponges = Cellular level

Quick Tips:
- Remember the levels of organization in different animal groups.

16 Easy

16 of 63

Understanding +4 | -1

Tissue level of organisation is seen in

View answer and explanation

Correct option: D

None of these

Option D (None of these) is correct because tissue level of organization is seen in Coelenterates (Cnidaria). Platyhelminthes have organ level of organization, Chordata have organ system level of organization and Arthropoda also have organ system level of organization.

Solution approach

Correct Answer + Core Reason: None of these. Tissue level of organization is seen in Coelenterates (Cnidaria).

Step-by-Step Solution:

Step 1: Define Tissue Level of Organization: Cells are organized into tissues with specific functions.

Step 2: Analyze the options:
- A. Platyhelminthes: Organ level of organization.
- B. Chordata: Organ system level of organization.
- C. Arthropoda: Organ system level of organization.
- D. None of these: Since the other options are incorrect, this is the correct answer.

Step 3: Identify the phylum with tissue level of organization: Cnidaria (Coelenterates) have tissue level of organization.

Step 4: Conclusion: None of the given options exhibit tissue level of organization. The correct answer is None of these.

Why other options are wrong:
- Option A: Platyhelminthes have an organ level of organization, not a tissue level.
- Option B: Chordata have an organ system level of organization, not a tissue level.
- Option C: Arthropoda have an organ system level of organization, not a tissue level.

Key Concepts:
- Levels of Organization: Cellular, Tissue, Organ, Organ System
- Animal Phyla: Platyhelminthes, Chordata, Arthropoda, Cnidaria

Memory Aids:
- Remember the order of organization: cells -> tissues -> organs -> organ systems.

Quick Tips:
- Know the level of organization for each major animal phylum.

17 Easy

17 of 63

Understanding +4 | -1

Choose the incorrect match.

View answer and explanation

Correct option: D

Pteropus - Air bladder is present

Option D (Pteropus - Air bladder is present) is the incorrect match because Pteropus (a bat) is a mammal and possesses lungs for respiration, not an air bladder which is found in bony fishes.

Solution approach

Correct Answer + Core Reason: Pteropus - Air bladder is present. This is an incorrect match because bats are mammals and have lungs, not air bladders.

Step-by-Step Solution:

Step 1: Evaluate each match:
- Vipera - Three chambered heart: Correct (reptiles generally have a three-chambered heart, except for crocodiles).
- Neophron - Air sacs supplement the respiration: Correct (birds have air sacs to aid respiration).
- Hemidactylus - Bony endoskeleton: Correct (reptiles have a bony endoskeleton).
- Pteropus - Air bladder is present: Incorrect (bats are mammals and have lungs, not air bladders).

Step 2: Identify the incorrect match. Pteropus (a bat) does not have an air bladder; it has lungs.

Why other options are wrong:
- Option A: Vipera - Three chambered heart: This is a correct match.
- Option B: Neophron - Air sacs supplement the respiration: This is a correct match.
- Option C: Hemidactylus - Bony endoskeleton: This is a correct match.

Key Concepts:
- Animal Physiology
- Respiratory Systems
- Circulatory Systems
- Animal Classification

Memory Aids:
- Mammals: Lungs, not air bladders.

Quick Tips:
- Know the key characteristics of different animal classes.

18 Easy

18 of 63

Understanding +4 | -1

Which of the following have porous body and are diploblastic?

View answer and explanation

Correct option: C

Sycon and spongilla

Option C (Sycon and spongilla) is correct because both Sycon and Spongilla are sponges (Porifera) with porous bodies and are diploblastic.

Solution approach

Correct Answer + Core Reason: Sycon and spongilla. Both Sycon and Spongilla are sponges (Porifera) with porous bodies and are diploblastic.

Step-by-Step Solution:
Step 1: Identify the animals that are Porifera (sponges).
Step 2: Sycon and Spongilla are sponges.
Step 3: Sponges have porous bodies and are diploblastic (two germ layers).

Why other options are wrong:
- Option A: Aurelia and Obelia are cnidarians, not sponges.
- Option B: Adamsia is a cnidarian, and Euplectella is a sponge, but the question asks for both to be sponges.
- Option C: Sycon and Spongilla are both sponges.
- Option D: Sycon is a sponge, but Hydra is a cnidarian.

Key Concepts:
- Porifera (sponges)
- Diploblastic organization

Memory Aids:
- Sycon and Spongilla = Sponges

Quick Tips:
- Remember the key examples of Porifera.

19 Easy

19 of 63

Remembering +4 | -1

‘Portuguese man of war’ is

View answer and explanation

Correct option: B

Physalia

Option B (Physalia) is correct because Physalia, commonly known as the Portuguese man-of-war, is a colonial hydrozoan belonging to the phylum Cnidaria.

Solution approach

Correct Answer + Core Reason: Physalia. Physalia is the correct scientific name for the \'Portuguese man of war.\'

Step-by-Step Solution:

Step 1: Recall the common names and scientific names of various marine organisms.

Step 2: Identify that the \'Portuguese man of war\' is a colonial organism with a characteristic float.

Step 3: Match the common name with the correct scientific name, Physalia.

Why other options are wrong:
- Option A: Obelia is a genus of hydrozoans, but not the \'Portuguese man of war.\'
- Option C: Aurelia is a genus of jellyfish.
- Option D: Branchiostoma is a lancelet, a type of cephalochordate.

Key Concepts:
- Animal classification
- Scientific nomenclature
- Cnidarian diversity

Memory Aids:
- Associate \'Physalia\' with \'Portuguese man of war\' through visual imagery of its float.

Quick Tips:
- Memorize common names and their corresponding scientific names for important marine organisms.

20 Easy

20 of 63

Analyzing +4 | -1

Select the odd one w.r.t. level of organisation.

View answer and explanation

Correct option: C

Cnidaria

Option C (Cnidaria) is the odd one out because Cnidaria exhibits tissue level of organization, while Annelida, Mollusca, and Aschelminthes exhibit organ system level of organization.

Solution approach

Correct Answer + Core Reason: Cnidaria. Cnidaria exhibits tissue level of organization, while the others exhibit organ system level.

Step-by-Step Solution:

Step 1: Analyze Annelida: Annelida exhibits organ system level of organization.

Step 2: Analyze Mollusca: Mollusca exhibits organ system level of organization.

Step 3: Analyze Cnidaria: Cnidaria exhibits tissue level of organization.

Step 4: Analyze Aschelminthes: Aschelminthes exhibits organ system level of organization.

Step 5: Identify the odd one out: Cnidaria has a tissue level of organization, while the others have an organ system level.

Why other options are wrong:
- Option A: Annelida has organ system level of organization.
- Option B: Mollusca has organ system level of organization.
- Option D: Aschelminthes has organ system level of organization.

Key Concepts:
- Levels of organization: cellular, tissue, organ, organ system
- Animal classification

Memory Aids:
- "COAT": Cellular (Porifera), Tissue (Cnidaria), Organ (Platyhelminthes), Organ system (Aschelminthes and onwards)

Quick Tips:
- Remember the levels of organization associated with different phyla.

21 Easy

21 of 63

Understanding +4 | -1

List the phyla in the correct order of their placement in classification
I. Chordata II. Annelida
III. Arthropoda IV. Platyhelminthes
V. Ctenophora VI. Aschelminthes

View answer and explanation

Correct option: C

V, IV, VI, II, III, I

Option C (V, IV, VI, II, III, I) is correct because it represents the correct evolutionary order of the listed phyla.

Solution approach

Correct Answer + Core Reason: V, IV, VI, II, III, I. This order reflects the evolutionary relationships among the phyla.

Step-by-Step Solution:

Step 1: Recall the general evolutionary progression of animal phyla.

Step 2: Ctenophora are among the earliest diverging animal lineages.

Step 3: Platyhelminthes are relatively simple, followed by Aschelminthes (Nematoda).

Step 4: Annelida and Arthropoda are more complex, segmented protostomes.

Step 5: Chordata are deuterostomes and considered more advanced.

Step 6: Therefore, the correct order is V, IV, VI, II, III, I.

Why other options are wrong:
- Option A: Incorrect order of phyla.
- Option B: Incorrect order of phyla.
- Option D: Incorrect order of phyla.

Key Concepts:
- Animal phylogeny
- Evolutionary relationships among phyla
- Protostomes vs. Deuterostomes

Memory Aids:
- Remember the general progression from simple to complex animals.

Quick Tips:
- Consider the key evolutionary innovations that define each phylum.

22 Easy

22 of 63

Remembering +4 | -1

Radial symmetry is NOT found in adults of phylum ______

View answer and explanation

Correct option: D

Hemichordata

Option D (Hemichordata) is correct because adult hemichordates exhibit bilateral symmetry, while the other phyla listed (Coelenterata, Echinodermata, Ctenophora) exhibit radial symmetry.

Solution approach

Correct Answer + Core Reason: Hemichordata. Adult hemichordates exhibit bilateral symmetry, unlike the other options.

Step-by-Step Solution:

Step 1: Define radial symmetry. Radial symmetry is when an organism can be divided into similar halves by multiple planes passing through a central axis.

Step 2: Consider each phylum:
- Coelenterata (Cnidaria): Exhibit radial symmetry.
- Echinodermata: Adults exhibit pentaradial symmetry (a type of radial symmetry).
- Ctenophora: Exhibit radial symmetry.
- Hemichordata: Exhibit bilateral symmetry.

Step 3: Identify the phylum that does NOT have radial symmetry in adults. Hemichordata is the only one with bilateral symmetry.

Why other options are wrong:
- Option A: Coelenterata: Coelenterates (Cnidarians) exhibit radial symmetry.
- Option B: Echinodermata: Adult echinoderms exhibit pentaradial symmetry.
- Option C: Ctenophora: Ctenophores exhibit radial symmetry.

Key Concepts:
- Radial Symmetry
- Bilateral Symmetry
- Animal Phyla

Memory Aids:
- Echinoderms: "Penta-"radial (five-fold symmetry).

Quick Tips:
- Know the symmetry types for major animal phyla.

23 Easy

23 of 63

Understanding +4 | -1

Animals are classified on the basis of which of the following features?
I. Coelomic cavity II. Level of organisation
III. Notochord IV. Skeletal structure

View answer and explanation

Correct option: C

I, II and III

Option C (I, II and III) is correct because coelomic cavity, level of organisation and notochord are all used in animal classification.

Solution approach

Correct Answer + Core Reason: I, II and III. Coelomic cavity, level of organisation, and notochord are all important features used in animal classification.

Step-by-Step Solution:

Step 1: Recall the basis of animal classification.

Step 2: Analyze each feature:
- I. Coelomic cavity: Presence or absence and type of coelom (e.g., acoelomate, pseudocoelomate, coelomate) are important.
- II. Level of organisation: Cellular, tissue, organ, or organ system level is a key classification criterion.
- III. Notochord: Presence or absence of a notochord distinguishes chordates from non-chordates.
- IV. Skeletal structure: While important, it is not as fundamental as the other three in initial classification.

Step 3: Conclusion: Coelomic cavity, level of organisation, and notochord are all used in animal classification.

Why other options are wrong:
- Option A: Only includes coelomic cavity and level of organization, omitting the notochord which is crucial for distinguishing chordates.
- Option B: Only includes coelomic cavity and notochord, omitting the level of organization which is a fundamental classification criterion.
- Option D: Only includes level of organization and skeletal structure, omitting the coelomic cavity and notochord which are more fundamental.

Key Concepts:
- Animal Classification
- Coelomic Cavity
- Level of Organization
- Notochord

Memory Aids:
- Remember the key features used to classify animals: body symmetry, germ layers, coelom, level of organization, and presence/absence of a notochord.

Quick Tips:
- Understand the hierarchy of animal classification and the key features used at each level.

24 Easy

24 of 63

Remembering +4 | -1

Read the statement and choose the correct option
Statement – Closed type of blood circulatory pathway is observed in
A. Annelida B. Arthropods C. Mollusca D. Cnidaria E. Chordates

View answer and explanation

Correct option: A

A and E

Option A (A and E) is correct because Annelida and Chordata are the only groups listed that exhibit a closed circulatory system.

Solution approach

Correct Answer + Core Reason: A and E. Annelids and Chordates are known to have closed circulatory systems.

Step-by-Step Solution:

Step 1: Define a closed circulatory system. In a closed circulatory system, blood is confined to vessels and is distinct from the interstitial fluid.

Step 2: Evaluate each option:
- Annelida: Have a closed circulatory system.
- Arthropods: Have an open circulatory system.
- Mollusca: Most have an open circulatory system (except cephalopods).
- Cnidaria: Have no circulatory system.
- Chordates: Have a closed circulatory system.

Step 3: Identify the correct combination. Only Annelida and Chordates have closed circulatory systems.

Why other options are wrong:
- Option B: B and E: Arthropods have an open circulatory system, so this is incorrect.
- Option C: C and E: Most mollusks have an open circulatory system, so this is incorrect.
- Option D: D and E: Cnidaria do not have a circulatory system, so this is incorrect.

Key Concepts:
- Closed Circulatory System
- Open Circulatory System
- Animal Phyla

Memory Aids:
- Annelids and Chordates: Think "AC" for "Always Closed" (circulatory system).

Quick Tips:
- Know the circulatory system types for major animal phyla.

25 Easy

25 of 63

Analyzing +4 | -1

All of the following are coelomates exhibiting three germ cell layers, except

View answer and explanation

Correct option: B

Aurelia

Option B (Aurelia) is the exception because Aurelia (a jellyfish, belonging to phylum Cnidaria) is diploblastic and has a tissue level of organization, not a coelom.

Solution approach

Correct Answer + Core Reason: Aurelia. Aurelia is diploblastic and does not have a coelom.

Step-by-Step Solution:

Step 1: Analyze Aplysia: Aplysia (a sea slug, belonging to phylum Mollusca) is a coelomate and triploblastic.

Step 2: Analyze Aurelia: Aurelia (a jellyfish, belonging to phylum Cnidaria) is diploblastic and has a tissue level of organization. Therefore, it is not a coelomate.

Step 3: Analyze Aptenodytes: Aptenodytes (a penguin, belonging to phylum Chordata) is a coelomate and triploblastic.

Step 4: Analyze Anopheles: Anopheles (a mosquito, belonging to phylum Arthropoda) is a coelomate and triploblastic.

Step 5: Identify the exception: Aurelia is not a coelomate and is diploblastic.

Why other options are wrong:
- Option A: Aplysia is a coelomate and triploblastic.
- Option C: Aptenodytes is a coelomate and triploblastic.
- Option D: Anopheles is a coelomate and triploblastic.

Key Concepts:
- Coelom types
- Germ layers: diploblastic vs. triploblastic
- Animal classification

Memory Aids:
- Cnidarians are diploblastic and have tissue level organization.

Quick Tips:
- Remember the phylum classifications and key characteristics of each organism.

26 Easy

26 of 63

Understanding +4 | -1

Canal system in Porifera is not concerned with

View answer and explanation

Correct option: D

None of the above

Option D (None of the above) is correct because the canal system in Porifera is involved in respiration, nutrition, and excretion, and it indirectly aids in sexual reproduction by facilitating sperm entry.

Solution approach

Correct Answer + Core Reason: None of the above. The canal system in Porifera is involved in respiration, nutrition, excretion, and indirectly in sexual reproduction.

Step-by-Step Solution:

Step 1: Understand the function of the canal system in Porifera.

Step 2: The canal system (e.g., asconoid, syconoid, leuconoid) is a network of water canals and pores that facilitate water flow through the sponge's body.

Step 3: Water flow is essential for:
- Respiration: Gas exchange occurs as water passes through the canals.
- Nutrition: Food particles are filtered from the water.
- Excretion: Waste products are carried away by the water current.
- Sexual Reproduction: Water currents carry sperm to the oocytes for fertilization (indirectly).

Step 4: Since the canal system is involved in all the listed processes (respiration, nutrition, and indirectly sexual reproduction), the correct answer is "None of the above".

Why other options are wrong:
- Option A: Respiration is incorrect because the canal system facilitates gas exchange.
- Option B: Nutrition is incorrect because the canal system helps in filtering food particles.
- Option C: Sexual reproduction is incorrect because the canal system indirectly aids in sexual reproduction by facilitating sperm entry.
- Option D: None of the above is the correct answer since the canal system is involved in all the other processes.

Key Concepts:
- Porifera (sponges) and their canal systems
- Functions of the canal system: respiration, nutrition, excretion, and indirect role in sexual reproduction.

Memory Aids:
- Remember that sponges are filter feeders, and the canal system is their way of getting food and oxygen.

Quick Tips:
- When dealing with animal kingdom questions, always remember the unique characteristics of each phylum.

27 Easy

27 of 63

Understanding +4 | -1

The point by which Annelida advanced over Nematoda is

View answer and explanation

Correct option: D

All of the above

Option D (All of the above) is correct because Annelida possess all the listed advancements over Nematoda: a true coelom, metameric segmentation, and a closed circulatory system.

Solution approach

Correct Answer + Core Reason: All of the above. Annelida advanced over Nematoda by having a true coelom, metameric segmentation, and closed circulation.

Step-by-Step Solution:

Step 1: Compare Annelida and Nematoda.

Step 2: Consider each feature:
- True coelom: Nematoda have a pseudocoelom, while Annelida have a true coelom.
- Metameric segmentation: Annelida exhibit metameric segmentation, which is absent in Nematoda.
- Closed circulation: Annelida have a closed circulatory system, while Nematoda lack a true circulatory system.

Step 3: Determine the correct answer. All of the listed features represent advancements in Annelida over Nematoda.

Why other options are wrong:
- Option A: True coelom: This is a valid advancement, but not the only one.
- Option B: Metameric segmentation: This is a valid advancement, but not the only one.
- Option C: Closed circulation: This is a valid advancement, but not the only one.

Key Concepts:
- True Coelom
- Pseudocoelom
- Metameric Segmentation
- Closed Circulatory System
- Animal Phyla

Memory Aids:
- Annelida: Think "Advanced" compared to Nematoda.

Quick Tips:
- Know the key characteristics of different animal phyla.

28 Easy

28 of 63

Remembering +4 | -1

Sponges are

View answer and explanation

Correct option: D

Sessile

Option D (Sessile) is correct because sponges are generally attached to a substrate and do not move freely.

Solution approach

Correct Answer + Core Reason: Sessile. Sponges are attached to a substrate and do not move freely.

Step-by-Step Solution:

Step 1: Define each term.

Step 2: Pelagic - Living in the water column, not near the bottom.

Step 3: Free-swimming - Able to swim freely in the water.

Step 4: Planktonic - Drifting in the water column.

Step 5: Sessile - Attached to a substrate, non-motile.

Step 6: Sponges are attached to a substrate and are therefore sessile.

Why other options are wrong:
- Option A: Pelagic - Sponges are not pelagic, as they live on the bottom.
- Option B: Free-swimming - Sponges are not free-swimming, as they are attached.
- Option C: Planktonic - Sponges are not planktonic, as they are attached.

Key Concepts:
- Sponge Lifestyle
- Sessile vs. Motile

Memory Aids:
- Sessile: Think of "sitting" still.

Quick Tips:
- Remember that sponges are attached to a substrate.

29 Easy

29 of 63

Remembering +4 | -1

Which of the following is true about phylum-Platyhelminthes?

View answer and explanation

Correct option: D

They are mostly endoparasites

Option D is correct because most Platyhelminthes are endoparasites, living inside the bodies of their hosts.

Solution approach

Correct Answer + Core Reason: They are mostly endoparasites. Most Platyhelminthes are endoparasites.

Step-by-Step Solution:
Step 1: Recall the different lifestyles of Platyhelminthes: free-living, ectoparasitic, endoparasitic, and commensal.
Step 2: Identify the most common lifestyle among Platyhelminthes.
Step 3: Most Platyhelminthes are endoparasites, living inside the bodies of their hosts.

Why other options are wrong:
- Option A: Some Platyhelminthes are ectoparasites, but most are not.
- Option B: Some Platyhelminthes are free-living, but most are not.
- Option C: Platyhelminthes are not mostly commensals.

Key Concepts:
- Lifestyle of Platyhelminthes.
- Endoparasitism.

Memory Aids:
- Think of tapeworms and flukes as examples of endoparasitic Platyhelminthes.

Quick Tips:
- Know the lifestyles of different animal phyla.

30 Easy

30 of 63

Remembering +4 | -1

Organ system level of organisation is observed in

View answer and explanation

Correct option: D

All of these

Option D (All of these) is correct because chordates, annelids, and molluscs all exhibit organ system level of organization.

Solution approach

Correct Answer + Core Reason: All of these. Chordates, Annelids and Molluscs all have organ system level of organization.

Step-by-Step Solution:

Step 1: Understand the question. The question asks which of the listed groups exhibit organ system level of organization.

Step 2: Recall the levels of organization: cellular, tissue, organ, organ system.

Step 3: Chordates: Have organ systems (e.g., digestive, circulatory, nervous).

Step 4: Annelids: Have organ systems (e.g., digestive, circulatory, nervous).

Step 5: Molluscs: Have organ systems (e.g., digestive, circulatory, nervous).

Step 6: Conclusion: All three groups exhibit organ system level of organization.

Why other options are wrong:
- Option A: Chordates are only one of the groups with organ system level.
- Option B: Annelids are only one of the groups with organ system level.
- Option C: Molluscs are only one of the groups with organ system level.

Key Concepts:
- Levels of organization (cellular, tissue, organ, organ system)
- Animal classification

Memory Aids:
- Organ systems are more complex than organs, tissues, or cells.

Quick Tips:
- Remember the hierarchy of biological organization.

Your Progress

Animal kingdom practice · Easy

Explore Other Chapters in BIOLOGY

Key Takeaways

Continue Your Practice

Your practice