Set-I: Past Entrance Papers

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(b) Pharyngeal gill slits are present in hemichordates and in chordates. The notochord is present in chordates only. The ventral tubular nerve cord is present in non-chordates.

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(b) Whales, dolphin’s, and seals are examples of aquatic mammals. Trygon and sharks are cartilaginous fishes.

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(c) (A)-(3),(B)-(4),(C)-(2),(D)-(1)
The annelid worms were thought to have evolved from a coelomate worm-like ancestor which developed metameric segmentation or metamerism and the segments were termed as somites or metameres.
Sponges or Porifera have a water transport or canal system. Water enters via minute pore (Ostia) in the body wall into the central cavity spongocoel from where it goes out via osculum. The body of the ctenophore bears eight external rows of ciliated comb plates which help in locomotion.
The name Cnidaria is derived from cnidocytes or cnidoblast that are found on the tentacles and body of the organism.

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(d) Housefly belong to the Muscidae family. Muscidae are a family of flies found in
the superfamily-Muscoidea. The family Muscidae is a large dipteran family comprised of more than 5000 species. Other options can be explained as: Firefly belongs to the Lampyridae family.

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(c)
(A) -(2),(B)-(3,(C)-(4),(D)-(1)
– Physalia belongs to
phylum-Coelenterata (Cnidaria) and is commonly known as Portuguese man-of-war.
– Limulus belongs to the phylum Arthropoda and is a living fossil commonly termed as king crab.
– Ancylostoma belongs to phylum-Aschelminthes and is commonly referred to as hookworm.
– Pinctada belongs to phylum-Mollusca and is commonly called pearl oyster.

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(d) Statements II, III, and V are correct, while statements I and IV are incorrect. The incorrect statement can be corrected as:
Comb plates are present in ctenophores which help in locomotion or swimming and not in digestion. Metagenesis is the alternation of generations between sexual and asexual reproduction. In helminths, metagenesis is not observed.

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(a) Pneumatic bones are hollow bones found in birds, which enable them to fly. Neophron is a bird.

Other options are incorrect because
– Hemidactylus is a reptile.
– Macropus is a mammal.
– Ornithorhynchus is a mammal.

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(a) Locusta is a gregarious pest. In Echinoderms, adults are radially symmetrical but larvae are bilaterally symmetrical. Scorpions respire through book lungs. Bioluminescence is well marked in ctenophores.

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(a) Platyhelminthes are bilaterally symmetrical, triploblastic, and acoelomate animals with organ level of organisation.

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(b) Animals belonging to phylum-Annelida are triploblastic, bilaterally symmetrical, and metamerically segmented.
They exhibit organ system level of body organisation with the presence of coelom. They may be aquatic (marine and freshwater) or terrestrial, free-living, and sometimes parasitic.

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(a) The members of subphylum-Vertebrata possess notochord during the embryonic period. The notochord is replaced by a cartilaginous or bony vertebral column in the adult. Thus, all vertebrates are chordates but, all chordates are not vertebrates.

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(c) In Vertebrata, the notochord is present during the embryonic period only as it is replaced by the vertebral column. In chordates, the central nervous system is dorsal and hollow.

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(c) Option (c) is the correct match which is as follows
Aptenodytes is penguin
Pteropus is a flying fox
Pterophyllum is angel fish
Petromyzon is lamprey

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(d) is correct. It can be explained as follows
Cyclostomes have an elongated body bearing 6-15 pairs of gill slits for respiration. The air bladder is present in bony fishes belonging to class-Osteichthyes which regulates buoyancy.
Trygon, a cartilaginous fish, possesses a poison sting.
The heterocercal caudal fin is present in members of class-Chondrichthyes.

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(a) is the correct match which is as follows
Platyhelminthes are bilaterally symmetrical with an incomplete digestive system, e.g. Taenia. Echinoderms are radially symmetrical with indirect development, e.g. starfish, sea urchin , etc. Hemichordates are cylindrical-bodied animals with no segmentation, e.g. Balanoglossus. Aves are warm-blooded animals with direct development like pigeons.

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(d) Annelids are true coelomates with bilateral symmetry. These exhibit organ-system level of body organisation with true coelom. They are triploblastic, metamerically segmented, and coelomate animals, e.g. earthworms.

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(a) (A)-(iii), (B)-(iv), (C)-(ii), (D)-(i)
Pila or apple snail contains a file-like rasping organ called radula for feeding. Bombyx or silkworm is an arthropod in which excretion occurs through Malpighian tubules. The body of ctenophore Pleurobranchia bears eight rows of ciliated comb plates, which help
in locomotion. In Taenia, excretion occurs through specialised cells called flame cells
which contain a protonephridia.

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(b) Ophiura is an echinoderm commonly known as a brittle star.
Physalia is a coelenterate (cnidarian) commonly known as Portuguese man of war.
Pinctada is a pearl oyster belonging to taxon bivalve molluscs. Planaria belongs to Platyhelminthes (flatworms).

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(a) Organ system of organisation, bilateral symmetry, and true coelomates with the segmented body are found in annelid, Arthropoda, and chordates.
In Mollusca, the body is unsegmented. 

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(b) Spongocoel is the central body cavity of the sponges. It is lined by highly specialised flagellated cells called choanocytes.

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(b) Ornithorhynchus and Tachyglossus are oviparous mammals. Crocodile is a reptile that possesses a four-chambered heart. In cartilaginous fish (except Chimaera) gills are not covered by an operculum.

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(a) All birds are oviparous while all mammals except Ornithorhynchus (duck-billed platypus) and Echidna or Tachyglossus (spiny anteater) are viviparous.

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(c) Phylum Chordata includes both jawless vertebrates (Agnatha) and jawed vertebrates (Gnathostomata). The crocodile of Class Reptilia has a four-chambered heart with two auricles and two ventricles. Duck-billed platypus and spiny anteater are oviparous mammals.

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(a) Parapodia are flattened, fleshy, vertical flaplike outgrowths of body wall found in annelids on lateral sides of trunk segments. These are hollow structures enclosing coelom which is continuous with that of trunk segments. These serve the dual purpose of locomotion and respiration.

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(d) Phylum Porifera (the sponges) has a cellular level of body organisation, with an inner cellular layer consisting of highly specialised flagellated cells called choanocytes (or collar cells). The development in this phylum is indirect as it includes a free-swimming larva called amphiblastula or parenchymula for dispersal of the species.

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(d) An alternation of generation between asexual and sexual phases of an organism is referred to as metagenesis. E.g. in Obelia (a coelenterate), polyps reproduce asexually and medusae reproduce sexually.

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(b) Petromyzon (Lamprey) belongs to the Class Cyclostomata of Phylum-Chordata. It is a jawless fish that lays eggs in freshwater. After metamorphosis, the young lampreys swim down to the sea where they remain for 3 or 4 years before reaching maturity when they once again migrate to streams or rivers to spawn and die. Gonads become mature at that time when adults return to rivers for spawning.

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(d) (i) Aves possess dry skin, without glands except oil gland near the base of the tail.
(ii) Pinnae are not found in aquatic animals and egg-laying mammals.
(iii) In cyclostomes, unpaired appendages (joints) are found.

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(a) Duck-billed platypus is an egg-laying mammal. It is found in the rivers in eastern Australia and Tasmania. It is a beaver-like monotreme about \(50-60 \mathrm{~cm}\) long and well adapted to live in water. Usually, two eggs are laid at a time. The female curls around them for incubation and remains inactive for about two weeks. Newly hatched young ones are very immature, naked, and blind and each is \(2.5 \mathrm{~cm}\) long.

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(a) Exoskeleton made of cuticle has enabled insects to live on land and to diversify to almost all the possible habitats. It gives them protection, and support and also helps to prevent desiccation.

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(d) Cnidarians are sac-like animals that are aquatic, mostly marine except a few like Hydra, are freshwater. They are the simplest organisms that have attained a tissue level of organization. Members of Ctenophora, Cephalochordata, and Echinodermata are exclusively marine.

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(b) Gorgonia (sea fan) is an animal belonging to the phylum Coelenterata. All animals lack cell wall.

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(b) Planaria possesses high degree of regeneration. Both epimorphosis, in which the missing parts are formed, and morphallaxis, in which the whole body can be regenerated from a fragment of the body, occurs.

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(b) Torpedo is a bottom-living marine fish, discharging electricity that is sufficient to stun prey such as small fishes, etc. A pair of electric organs are situated on the dorsal side of the trunk region. In fact, the electric organs are the modified lateral muscle plates innervated by the cranial nerves.

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(a) Spiny anteater (Echidna) is a prototherian mammal whereas, sea urchins and sea cucumber are echinoderms. Silverfish (Lepisma) is an insect, Cuttle fish (Sepia) is a mollusc, and flying fish (Exocoetus) is a bony fish. Centipede is class chilopoda, Millipede is class diplopoda, and Scorpion and Spider are class arachnida of Phylum Arthropoda.

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(a) Prawn, Scorpion, and Locusta belong to the phylum Arthropoda. All other animals categories are given below:
\(\begin{array}{ll}\text { Sponge } & \rightarrow \text { Porifera } \\ \text { Sea anemone } & \rightarrow \text { Coelenterata } \\ \text { Starfish } & \rightarrow \text { Echinodermata } \\ \text { Malarial parasite, Amoeba } & \rightarrow \text { Protozoa } \\ \text { Mosquito } & \rightarrow \text { Arthropoda } \\ \text { Earthworm } & \rightarrow \text { Annelida } \\ \text { Pinworm } & \rightarrow \text { Aschelminthes } \\ \text { Tapeworm } & \rightarrow \text { Platyhelminthes }\end{array}\)

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Ans: (c)

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(d) Phylum Arthropoda is the largest phylum of Animalia which includes insects. Examples include Apis, silkworm, Laccifer, silverfish (Lepisma), locust, etc. Pufferfish and flying fish (Exocoetus) are examples of superclass Pisces, while cuttlefish (Sepia) belong to Mollusca.

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(d) Reptiles represent the first class of vertebrates fully adapted for life in dry places on land. The characters of reptiles are in fact a combination of characters that are found in fish and amphibians on one hand and birds and mammals on the other. Their exoskeleton is of horny epidermal scales, shields, plates, and scutes. The skin is dry, cornified, and devoid of glands. Reptiles lack external ears and have immovable eyelids.

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(d) In ctenophores, asexual reproduction is absent. They are monoecious and fertilization is generally external. In cnidaria, asexual reproduction (budding) is found in the polyps and sexual reproduction is found in the medusa form. Both asexual and sexual reproduction occur in Porifera (sponges). Asexual reproduction occurs by budding and gemmules. In protozoa, asexual reproduction takes place by binary fission, budding, etc. and sexual reproduction takes place by syngamy and conjugation.

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(d) Duckbilled platypus is oviparous and belongs to class Mammalia. Millipede belongs to class Diplopoda. Sea anemone has two germ layers, i.e., diploblastic. Silverfish (Lepisma) belongs to nonchordata. It is an insect.

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(a) The respiratory system is well developed in a cockroach in order to compensate the poorly developed circulatory system. It consists of tracheae, tracheoles, and spiracles. The main tracheal trunks open to the exterior on body surface through 10 pairs of segmentally arranged apertures termed spiracles or stigmata. Two pairs of spiracles are thoracic, one between pro and mesothorax and the other between meso and metathorax. Haemocoel contains a network of elastic, closed, and branching air tubes or tracheae. The ultimate finer branches of tracheae are called tracheoles which come in contact with the individual body cells. The elaborate tracheal system carries oxygen directly to all the body cells.

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(b) Pheretima (earthworm) and related organisms feed upon the decaying organic matter found in the soil. They also feed on the bits of plants and animal matter. Thus, they are omnivorous.

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(a) Pila belongs to the phylum mollusca. The body of molluscs (soft-bodied animals) is unsegmented, with a distinct head, muscular foot, and visceral hump. Radula is found in mouth of Pila.

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(d) Sea horse (Hippocampus) and flying fish (Exocoetus) belong to class osteichthyes of superclass pisces. They have two-chambered heart (one auricle and one ventricle) and are cold-blooded animals.

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(b) Heart is generally 3 -chambered in reptiles but in crocodile, it is 4-chambered. Sponges are generally marine and have collared cells but few fresh water forms can also be seen like Spongilla. All mammals are viviparous (giving birth to young ones) with an exception, Ornithorhynchus (platypus), which is oviparous (egg-laying).

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(c) Reptilia possess 3 -chambered heart with an incompletely divided ventricle and two atria. However, the crocodile is an exception as it has a 4-chambered heart. Chordata possesses a mouth provided with an upper and a lower jaw except for jawless fishes. All Chondrichthyes possess a cartilaginous endoskeleton without exception. Mammalia gives birth to young ones. However, Monotremes are mammals that lay eggs instead of giving birth to live young.

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(c)

\(
\begin{array}{|l|l|l|}
\hline \text { Genus name } & \text { Two Characters } & \text { Class/Phylum } \\
\hline \text { Pteropus } & \begin{array}{l}
\text { (a)Skin possess hair } \\
\text { (b)Viviparous }
\end{array} & \text { Mammalia } \\
\hline
\end{array}
\)

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(c) Humans are mammals which are chordates. Phylum chordata includes animals that possess a notochord either throughout or during early embryonic life. In Ascidia (urochordata), notochord is present only in larval tail while in Amphioxus (cephalochordata), it extends from head to tail region and is persistent throughout their life. It is replaced by a vertebral column in the adult frog.

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(d) The animals which possess true coelom are called eucoelomates or coelomates. The true coelom is a body cavity which arises as a cavity in embryonic mesoderm. The true coelom is of two types; schizocoelom (schizocoel) and enterocoelom (enterocoel). Schizocoelom develops as a split in the mesoderm sheet. It is found in annelids, arthropods, molluscs. In enterocoelom, mesoderm arises from the wall of the embryonic cut of enteron as hollow outgrowths. It occurs in echinoderms and chordates.

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(d) In male frogs, two ureters act as a urinogenital duct which open into the cloaca. They run backwards from the kidneys and open into the cloaca. In female ureters carry urine alone, while in male both sperms and urine are carried. Hence, are called urinogenital ducts.

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(d) In Fasciola (flatworms) the body has a single cavity with one opening to the outside. The single opening functions as both mouth for ingestion (intake of food) and anus for egestion (undigested food is passed out). It is called blind sac plan. Other examples are coelenterates.

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(c) Spongilla is a common, widely distributed freshwater sponge belonging to phylum porifera. The Canal system in Spongilla is essentially of rhagon type with choanocytes restricted to small rounded chambers. It is not found in leech, dolphin, and penguin.

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(a) Triploblastic is a condition which describes an animal having a body composed of three embryonic germ layers: the ectoderm, mesoderm, and endoderm. Most multicellular animals belonging to phylum platyhelminthes to phylum chordata are triploblastic. Ctenophores, sponges, and corals are diploblastic.

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(a) Acoelomates are animals having no body cavity or coelom. Examples are poriferans coelenterates, ctenophora, platyhelminthes, and nemertinea. In pseudocoelomates, body space is pseudocoelom or false coelom. Examples are ectoprocta, aschelminthes. In coelomates, body space is a true coelom enclosed by mesoderm on both sides. Remaining phyla of bilateria, from annelida to arthropoda are coelomates. Molluses and insects are coelomates while flatworms are acoelomates.

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(d) Animals belonging to Phylum Chordata are fundamentally characterised by the presence of a notochord, a dorsal hollow nerve cord, and paired pharyngeal gill slits. Crocodile, penguin, whale, and dogfish are all chordates. All of them have gill slits or have had it during embryonic development. Thus, paired gill slits are present in these animal at some stage of life.

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(a) Aschelminthes is a superphylum consisting of pseudocoelomates. These are mostly aquatic, free-living or parasitic. Their body is slender, bilaterally symmetrical, and triploblastic.

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(b) Agnatha is a subphylum or superclass of marine and freshwater vertebrates that lack jaws. They are fish-like animals with cartilaginous skeletons and well-developed sucking mouthparts with horny teeth. The only living agnathans are lampreys and hagfishes (Class Cyclostomata), which are parasites or scavengers.

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(c) Birds have originated from some ancestral reptilian stalk. These two classes have so many features in common that link the two groups. The evidence of reptilian ancestry of birds is furnished by their comparative anatomy, embryology, and palaeontology. One of the features is that all birds have horny epidermal scales confined to the lower parts of their legs and feet, which are exactly like the epidermal scales of the reptiles.

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(d) Ascaris belong to the Phylum Nematoda of Superphylum Aschelminthes. They have a cylindrical body without showing any metamerism, a pseudocoel (false coelom), and a complete digestive tract lined by endodermal epithelium. The cuticle covering the body surface bears minute transverse striations giving a pseudosegmented appearance to the worm.

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(a) Scorpion, spider, and cockroach belong to Phylum Arthropoda and are invertebrates. They possess ventral solid central nervous system which consists of a dorsal brain connected with a nerve ring to a double ventral nerve cord.

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(c) Arthropods are the largest phylum of Kingdom Animalia that characteristically possesses an outer body layer – the cuticle. The body is composed of segments usually forming distinct specialized body regions, i.e., head, thorax, and abdomen. In them, the trachea or windpipe or book lungs are the respiratory organs found in terrestrial forms, which help in respiration

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(a) Phylum Annelida comprises invertebrates, which are segmented worms having cylindrical soft bodies showing metameric segmentation. These are triploblastic animals showing bilateral symmetry. A true coelom is present which is filled with coelomic fluid containing cells. Annelids are perhaps the first animals to have a true schizocoelic coelom.

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(d) Reptiles have two auricles and a partly divided ventricle except crocodiles which have four-chambered heart. Obelia shows metagenesis i.e., alternation of generations which may be defined as a phenomenon in which diploid asexual phase alternates with haploid sexual phase. Lemur has a thecodent teeth i.e., the teeth are embedded in the sockets of the jaw bone.

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(a) Leech possesses a ventral central nervous system. Scorpion has a dorsal heart. Pharyngeal gill slits and post-anal tail are characteristic features of chordates. Chameleon is a chordate, so it possesses pharyngeal gill- slits in the embryonic stage. Octopus is a non-chordate.

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(d) Homoiothermy is the maintenance by an animal of its internal body temperature at a relatively constant value by using metabolic processes to counteract fluctuations in the temperature of the environment. Homoiothermy occurs in birds and mammals, which are described as endotherms. The heat produced by their tissue metabolism and the heat lost to the environment are balanced by various means to keep body temperature constant: \(36-38^{\circ} \mathrm{C}\) in mammals and \(38-40^{\circ} \mathrm{C}\) in birds. The hypothalamus in the brain monitors blood temperature and controls thermoregulation by both nervous and hormonal means. Thus parrot (bird) and platypus and kangaroo (mammals) are homoiothermic animals.

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(a) Nereis, scorpion, cockroach, and silver fish are all invertebrates and thus possess dorsal heart. Nereis is a marine animal while other animals mentioned in the question are terrestrial. Nereis belongs to Phylum Annelida while the rest of the animals belong to Phylum Arthropoda. Jointed appendages are present in scorpion, cockroach, and silverfish.

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(c) Ctenophora is a small phylum of exclusively marine, invertebrate animals. Ctenoplana and Beroe are examples of ctenophora. They have biradial symmetry (a combination of radial and bilateral symmetries). They lack the specialized stinging cells (nematocysts) found in coelenterates, but one species (Haeckelia Rubra) incorporates those of its jellyfish prey for its own defense.

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(c) Centipede, cockroach, and crab all belong to phylum Arthropoda which are characterized by jointed legs and chitinous exoskeleton. Arthropods have a bilaterally symmetrical and metamerically segmented body with haemocoel and open blood vascular system.

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(a) Kangaroo, hedgehog, dolphin, and Loris are mammals and thus give birth to young ones. Ostrich and kiwi are brids that lay eggs. Platypus is a most primitive living mammal that lays eggs. Other animals in the options are mammals and give birth to young ones.

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(d) Living fossil is a term for any living species (or clade) of organism which closely resembles species otherwise only known from fossils and has no close living relatives. These species have all survived major extinction events, and generally retain low taxonomic diversities.

Some examples of living fossils in animals are coelocanth, coral (polyp), crocodylia (crocodiles, gavials, and alligators), horseshoe crab (Limulus polyphemus), monotremes (Platypus and Echidna), snout-nosed frog (Nasikabatrachus sahyadrensis). Archaeoptery \(x\) is the earliest and most primitive known bird to date. It lived in the Jurassic Period around 150-155 million years ago. It has feathers and wings but it also had teeth and a skeleton similar to a small carnivorous dinosaur, therefore, it had both bird and theropod dinosaur features. Archaeopteryx is a powerful piece of evidence that shows that birds have evolved from dinosaurs.

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(d) Migration is the seasonal movement of complete populations of animals to a more favourable environment. It is common in mammals (e.g. porpoises), fish (e.g. eels and salmon), and some insects but is most marked in birds. The arctic tern, for example, migrates annually from its breeding ground in the Arctic circle to the Antarctic. Salmon usually migrate from marine to freshwater to spawn. The Siberian crane, breeds in arctic Russia in Yakutia and western Siberia. It is a long distant migrant. Salamander is an amphibian with slender body, short legs, and long tail. Outside the breeding season, they are seldom seen as they spend most of their time underground.

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(d) The term metamerism refers to a linear repetition of parts in an animal body. It occurs in three highly organized phyla: Annelida, Arthropoda, and Chordata. Each segment is called a metamere, or somite. Segmentation often affects both external and internal structures. Such a condition is called metameric segmentation. In chordates, the segmentation is apparent only in the embryonic stage. In the adult chordates, segmentation is visible in the internal structures, such as vertebrae, ribs, nerves, and blood vessels. Other animals have unsegmented bodies.

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(d) Mollusca includes those animals which have soft bodies, usually furnished with a shell. The body is often divided into a head, with eyes or tentacles, a muscular foot, and a visceral mass housing the organs. Loligo (squid or sea arrow), Teredo (shipworm), and Octopus are some of their examples.
In option (a) Spongilla and Euplectella belong to Porifera but Pennatula (the sea pen or sea feather) belongs to Coelenterata. In option (b) Physalia and Aurelia belong to cnidaria but Bonellia belongs to Phylum Annelida. In option (c) Planaria and Schistosoma belong to Platyhelminthes but Enterobius (Pinworm) belongs to aschelminthes.

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(a) Platyhelminthes do not have body cavity so they are acoelomates. In annelids, the body cavity is true and schizocoelous. Both annelids and platyhelminthes have bilateral symmetry.

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(a) Body in arthropoda is segmented. Segments are grouped into 3 forms – head, thorax, and abdomen. When head and thorax are fused then they are referred to as cephalothorax. Class Insecta of Phylum Arthropoda have body divided into head, thorax, and abdomen.

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(d) Echinoderms are triploblastic animals with organ system level of organisation. Larval forms possess bilateral symmetry while adults have radial symmetry.

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(d) It is universally accepted that amphibians (frogs) have originated from fishes. The resemblance of amphibia to fish is seen in most systems of the body. Both are cold-blooded. Fish respire by gills and also tadpole of frog respires by gills. To prevent desiccation in the air, both usually lay eggs in water.

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(c) Uricotelism means excretion of uric acid. Uric acid excretion occurs in organisms which develop in an enclosed egg (where water is severely limited) or which normally experience a very dry terrestrial environment as adult organisms. Uric acid is discharged as thick paste or as solid pellet: Examples: terrestrial reptiles, birds, insects, gastropod mollusc, etc.

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(b) The unique feature of mammals is the presence of diaphragm. It is a membrane that separates thoracic cavity from abdominal cavity. The cavity of other animals is not divided into thoracic and abdominal cavities. Homeothermy, four-chambered heart and rib cage are the characters of mammals as well as some other animals also.

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(d) Amoeba is a fresh water protozoan containing contractile vacuole that is meant for osmoregulation. When Amoeba is placed in marine water, then the water from the contractile vacuole will move out resulting in decrease in size of it. Contractile vacuole will increase in size if it is placed in a hypotonic solution. Water will enter into a contractile vacuole, thus increasing its size and ultimately it will burst and disappear.

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(a) Amoeba forms a cyst and reproduces by multiple fission, during adverse environmental conditions. The animal secretes a three-layered, protective, chitinous cyst around it and becomes inactive. Inside the cyst, the nucleus repeatedly divides to form several daughter nuclei, which arrange themselves near the periphery. Each daughter nucleus becomes enveloped by a small amount of cytoplasm, thus forming a daughter amoeba, called amoebula or pseudopodiospore. When favourable conditions arrive, the cyst breaks off liberating the young pseudopodiospores, each with fine pseudopodia. They feed and grow rapidly to become adults and lead an independent life.

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(c) Systemic heart refers to the entire heart of lower vertebrates. This heart pumps blood to body parts and not the lungs.

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(b) Sycon, belonging to the Phylum Porifera, are multicellular organisms with cellular level of body organisation. The constituent cells perform their functions more or less independently. No distinct tissue or organs are present in it.

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(b) In Musca, development is indirect with complete metamorphosis (holometaboly) including four stages as follows – egg, larva, pupa, and adult. In complete metamorphosis, the larva after hatching moults several times to become a fully grown one. It later becomes a pupa within a secreted case, called the puparium. Pupa differentiates into the young adult that breaks the puparium open and emerges outside. Then it grows into a mature form.