Animal Kingdom

Both the assertion and the reason are correct, and the reason provides an accurate explanation for the assertion.

Members of the subphylum Vertebrata possess a notochord during their embryonic stage. This notochord is later replaced by a cartilaginous or bony vertebral column in the adult stage, distinguishing vertebrates within the chordates. Hence, while all vertebrates fall under the category of chordates due to the presence of a notochord, not all chordates develop into vertebrates, as some retain the notochord throughout their life.

All living members of class Cyclostomata are ectoparasites.

Water vascular system in Echinoderms helps in locomotion, capture and transport of food and respiration. Excretory system is absent in echinoderms. Excretion takes place through general body surface.

The copulatory (nuptial) pad in male frogs develops on the first digit (the “thumb”) of the fore-limb, so the correct choice is:

Option B: First digit of the fore limb.

To match List-I with List-II correctly, let's consider the characteristics and common representatives of each class of animals mentioned:

Chondrichthyes: This class includes cartilaginous fishes such as sharks. Among the options, Carcharodon (Great White Shark) fits this class.

Cyclostomata: This class includes jawless fish like lampreys and hagfishes. Among the options, Myxine (hagfish) fits this class.

Osteichthyes: This class includes bony fishes. Among the options, Clarias (catfish) fits this class.

Amphibia: This class includes amphibians. Among the options, Ichthyophis (a type of caecilian, which is an amphibian) fits this class.

Therefore, the correct matching should be:

(A) Chondrichthyes -> (II) Carcharodon

(B) Cyclostomata -> (III) Myxine

(C) Osteichthyes -> (I) Clarias

(D) Amphibia -> (IV) Ichthyophis

The correct answer is:

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

An open circulatory system is a type of circulatory system in which the blood is not entirely contained within blood vessels. Instead, the blood is pumped from the heart into the body cavities, where tissues are directly bathed in blood. This is typical of many invertebrates, including arthropods and some mollusks.

Let's analyze the options provided:

Option A: Palaemon, Nereis, Balanoglossus

- Palaemon is a type of prawn (crustacean, arthropod).

- Nereis is a polychaete worm (annelid).

- Balanoglossus is a hemichordate.

Here, Palaemon has an open circulatory system, but the other two do not fit this category.

Option B: Hirudinaria, Bombyx, Salpa

- Hirudinaria, a leech (annelid).

- Bombyx, the silkworm moth (arthropod).

- Salpa, a type of tunicate (urochordata).

Bombyx has an open circulatory system, but the other two do not.

Option C: Anopheles, Limax, Limulus

- Anopheles, a mosquito (arthropod).

- Limax, a type of slug (mollusk).

- Limulus, the horseshoe crab (arthropod).

All three organisms listed in Option C have an open circulatory system.

Option D: Pheretima, Musca, Pila

- Pheretima, an earthworm (annelid).

- Musca, the common housefly (arthropod).

- Pila, an apple snail (mollusk).

Musca and Pila have an open circulatory system, but Pheretima does not.

Based on this analysis, the correct answer is:

Option C: Anopheles, Limax, Limulus

To evaluate which pair is an incorrect match, let's analyze the characteristics of each mentioned group in the options.

Option A: Annelids and arthropods - Bilateral symmetry

Annelids (segmented worms) and arthropods (such as insects, spiders, and crustaceans) both exhibit bilateral symmetry. This means they have a body plan that can be divided into symmetrical halves along a single plane. Therefore, this match is correct.

Option B: Sponges - Acoelomates

Sponges are indeed acoelomates. They lack a true body cavity (coelom) and are known for their simple, porous body structure. Hence, this match is also correct.

Option C: Coelenterates and Ctenophores - Radial symmetry

Both coelenterates (such as jellyfish and corals) and ctenophores (comb jellies) possess radial symmetry. Radial symmetry means their body parts are arranged around a central axis. Thus, this match is correct.

Option D: Platyhelminthes - Diploblastic organisation

Platyhelminthes, commonly known as flatworms, actually exhibit triploblastic organisation, meaning their body structure arises from three primary germ layers: the ectoderm, mesoderm, and endoderm. Diploblastic organisms have only two germ layers: the ectoderm and endoderm. Therefore, this match is incorrect.

So, the incorrect match is Option D: Platyhelminthes - Diploblastic organisation.

The correct answer is Option A: A is true but R is false.

Let's break down why:

Assertion A: This statement is true. Vertebrates, belonging to the subphylum Vertebrata, do indeed possess a notochord during their embryonic development. This notochord is a flexible rod that provides support. As the embryo develops, the notochord is gradually replaced by a vertebral column, which can be either cartilaginous or bony depending on the species.

Reason R: This statement is false. The statement "Thus all chordates are vertebrates, not all vertebrates are chordates" is incorrect. The relationship between chordates and vertebrates is actually the opposite.

Here's the correct relationship:

• Chordates: This is a phylum that includes all animals possessing a notochord at some point in their life cycle. They also have other key features like a dorsal hollow nerve cord, pharyngeal slits, and a post-anal tail.
• Vertebrates: This is a subphylum within the chordates. Vertebrates are distinguished by the presence of a vertebral column.

Therefore, all vertebrates are chordates, but not all chordates are vertebrates. There are other groups within the chordate phylum that lack a vertebral column, such as tunicates and cephalochordates.

In conclusion, Assertion A is a correct statement about the development of vertebrates. However, Reason R misrepresents the relationship between chordates and vertebrates.

To solve this matching question, we must evaluate each term in List I and determine its corresponding class or phylum in List II. Let's analyze each match:

Pleurobrachia: Pleurobrachia is a genus that belongs to the phylum Ctenophora, which is commonly known as comb jellies. Thus, A should be matched with II (Ctenophora).

Radula: A radula is a toothed, chitinous organ found within mollusks that is used for scraping or cutting food before the food enters the esophagus. Hence, B should be matched with I (Mollusca).

Stomochord: The stomochord is a small, tubular structure found in the collar of hemichordates, a fundamental character previously thought to link hemichordates and chordates. Therefore, C should be matched with IV (Hemichordata).

Air bladder: The air bladder, or swim bladder, is a gas-filled sac present in many bony fish that helps to maintain buoyancy. Hence, D should be matched with III (Osteichthyes, a class of bony fish).

Now, let's review the options given:

• Option A: A-IV, B-II, C-III, D-I
• Option B: A-II, B-I, C-IV, D-III
• Option C: A-II, B-IV, C-I, D-III
• Option D: A-IV, B-III, C-II, D-I

The correct matches, based on the classification should be: A-II, B-I, C-IV, D-III. Therefore, the correct answer is:

Option B

Let's evaluate each statement with regard to the type of body cavity they describe:

A. Annelids are true coelomates: This statement is correct. Annelids (segmented worms, including earthworms) possess a true coelom, which is a body cavity fully lined with a mesodermal layer more specifically called peritoneum. This allows for the distinction of the internal organs from the body wall, and it facilitates greater complexity and organization of the internal structures.

B. Poriferans are pseudocoelomates: This statement is incorrect. Poriferans (sponges) do not have any type of body cavity. Sponges are at a basic level of complexity and lack true tissues and organs, including a coelom or a pseudocoelom. They are considered to have no body cavity and are thus neither coelomates nor pseudocoelomates.

C. Aschelminthes are acoelomates: This statement is incorrect. Aschelminthes, more commonly referred to as Nematoda or roundworms, are actually pseudocoelomates. They possess a pseudocoelom, which is a body cavity that is not entirely lined by mesodermal tissue, unlike a true coelom. The pseudocoel serves as a rudimentary circulatory system and provides a space for internal organs.

D. Platyhelminthes are pseudocoelomates: This statement is incorrect. Platyhelminthes (flatworms) are acoelomates, meaning they lack any body cavity. Their bodies are solid between the digestive tract and the body wall, lacking a filled cavity that would separate these structures.

From the analysis above, only statement A is accurate:

• A. Annelids are true coelomates - Correct
• B. Poriferans are pseudocoelomates - Incorrect
• C. Aschelminthes are acoelomates - Incorrect
• D. Platyhelminthes are pseudocoelomates - Incorrect

Thus, the correct answer to the question is:

Option B: A only

Let's analyze the match between the items in List I and those in List II. We will specifically address the scientific names provided in List I and match them with their common names given in List II:

List I (Scientific Names) with List II (Common Names):

• Pterophyllum (A) -> Angel fish (III): Pterophyllum is the scientific name for a type of cichlid commonly called angel fish. Therefore, A matches with III.
• Myxine (B) -> Hag fish (I): Myxine is the genus for hagfish, which are known for their slime-producing capability. Hence, B matches with I.
• Pristis (C) -> Saw fish (II): Pristis is the genus comprising the sawfishes, which are known for their long, saw-like rostrums. Consequently, C matches with II.
• Exocoetus (D) -> Flying fish (IV): Exocoetus is a genus of marine fish known as flying fish, due to their ability to glide above the water's surface for short distances. Therefore, D matches with IV.

Now, compiling these matches together:

• A - III
• B - I
• C - II
• D - IV

The correct option that matches each scientific name with their respective common names accordingly is:

Option B:

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

The correct answer is Option C: B, D & E only. Here's why:

• B. Notochord is absent: This is the defining characteristic of non-chordates. Chordates possess a notochord at some stage of their development, while non-chordates do not.


• D. Heart is dorsal if present: In non-chordates with a circulatory system, the heart is located on the dorsal (back) side of the body, unlike chordates where it's ventral (front).


• E. Post anal tail is absent: Non-chordates lack a post-anal tail, a feature present in chordates.

• A. Pharynx is perforated by gill slits: This is a characteristic of chordates, particularly in aquatic forms for respiration.


• C. Central nervous system is dorsal: While this is true for chordates, non-chordates have a ventral nerve cord.

The correct answer is :

Option D : (A)-(II), (B)-(I), (C)-(III), (D)-(IV)

Explanation :

(A) Contractile vacuoles are found in single-celled organisms like Amoeba (II). They help in osmoregulation by expelling excess water out of the cell.

(B) A water vascular system is a unique characteristic of echinoderms such as Asterias (I), a genus of starfish. This system is involved in locomotion, feeding, respiration, and excretion.

(C) The canal system is characteristic of sponges such as Spongilla (III). It aids in the circulation of water for feeding, respiration, and excretion.

(D) Flame cells are part of the excretory system in platyhelminthes like Taenia (IV), commonly known as tapeworm. These cells function in osmoregulation and excretion.

Option (4) is the correct answer because Chelone (turtle) is a reptile and the heart of reptiles are usually three-chambered except crocodiles.

Option (1) is incorrect as Pteropus (flying fox) possess four -chambered heart.

Option (2) and (3) are incorrect as Scoliodon (dog fish) and Hippocampus (sea horse) possess two - chambered heart.

$\bullet$ Penicillium asexually reproduces by conidia formation

$\bullet$ Chlamydomonas asexually reproduces by zoospores

Hydra reproduces by budding whereas sponges produce gemmules for asexual reproduction

Option (d) is the correct answer because statement (b) is false as cyclostomes have a circular mouth without jaws and statement (d) is false as they migrate from marine water to fresh water for spawning. Statements (a) and (c) are correct for cyclostomes as they have 6-15 pairs of gills and body is divoid of scales and paired fins.

Option (3) is the correct answer as chitin forms the exoskeleton is arthropods and is found in fungal cell wall. N-acetyl glucosamine is the monomeric unit. Cellulose is a polysaccharide. Cutin is a derived lipid.

Option (a) is the correct answer because all chordates are divided into three subphyla - Urochordata, Cephalochordata and Vertebrata. In subphylum Vertebrata, notochord is replaced by bony or cartilaginous vertebral column in adults. Therefore, all vertebrates are chordates but all chordates are not vertebrates.