31 Years NEET Previous Year Questions: Animal Kingdom - 2 - NEET MCQ

Acoelomates are animals that have no body cavity or coelom. The examples are poriferans, coelenterates, ctenophore, Platyhelminthes and nemertean. pseudocoelomates are animals that has false or pseudo coelom. Examples are aschelminthes. Coelomates are animals that has true coelom enclosed by mesoderm on both sides. Examples: from annelida to arthropoda are coelomates. Hence roundworms are pseudocoelomates, molluses and insects are coelomates while flatworms are acoelomates.

Line in NCERT: "The body cavity is not lined by mesoderm, instead, the mesoderm is present as scattered pouches in between the ectoderm and endoderm. Such a body cavity is called pseudocoelom and the animals possessing them are called pseudocoelomates, e.g., aschelminthes."

A male shark possesses a pair of claspers which are inserted into a female shark’s cloaca (an opening on the underside of the body) at the time of mating. Claspers are located on the inner edge of the pelvic fins near the male’s cloaca. The function of claspers is to introduce sperm into a female shark’s body for the purpose of fertilizing her eggs. Female sharks do not have claspers.

In nature insects have the highest number of species (30 million). Fungi have 100,000, angiosperms have 260000 and birds have 10,000 species.

Chondrichthyes are the cartilaginous fish with a flexible skeleton made of cartilage rather than bone.

The correct option is B.

Ascaris belongs to Aschelminthes there is no segmentation of its body.

Pteropus is a flying fox. It is viviparous and mammals.

Aurelia is coelentra but only tissue level organisation is present. 

Salamander is an amphibian and it has tympanic membrane and external fertilization.

The notochord is a flexible rod-like structure that forms the main support of the body in the lowest chordates. In humans, the notochord is present during the embryonic stage and is replaced by the vertebral column in adults. Thus, the statement "It is absent throughout life in humans from the very beginning" is incorrect. The correct statement is that the notochord is present in the embryonic stage and later replaced by the vertebral column.

Human possesses enucleated RBC in mature state. But frog blood has both white and red blood cells which are nucleated. Frog cells do not lack platelets.

From annelida to chordata all are eucoelomate. C-Mollusca (Octopus), D-Arthropoda (Scorpion) have a true coelom.

Molluscans are soft bodied animals. Their body is unsegmented with a distinct head, muscular foot and visceral hump. In Pila the buccal cavity contains a resping organ, the radula with transverse rows of teeth.

Sea horse and flying fish are cold blooded animals. Ornithorhyncus is oviparous. Crocodile has four chambered heart. Ascaris and Ancylostoma are segmented roundworms.

Prawn, Scoripion, Locusta belong to phylum-Arthropoda
Malarial parasite (Plasmodium vivax) and Amoeba belong to phylum-Protozoa.

Mosquito- Phylum- Arthropoda
Pinworm and
Tapeworm- Phylum-  Platyhelminthes

Sponge-phylum-Porifera, Sea abemone-phylum-Coelenterata
Starfish-phylum-Echinodermata

Ichthyophis – Amphibian
Limulus – Arthropoda
Adamsia – Cnidaria
Petromyzon – Jawless vertebrate & ectoparasite, cyclostomate

 House fly, butterfly, tse tse fly,  silverfish all belongs to insecta.

Representive of Phylum Ar thropoda is silverfish. Arthropoda is the largest phylum of Animalia, which covers two-thirds of all named species.

Line in NCERT: "Examples: Economically important insects Apis (Honey bee), Bombyx (Silkworm), Laccifer (Lac insect) Vectors (Mosquitoes) - Anopheles, Culex and Aedes Gregarious pest - Locusta (Locust) Living fossil - Limulus (King crab)."

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, cornifled and devoid of glands. Reptiles lack external ears and have immovable eyelids.

Line in NCERT: "they are mostly terrestrial animals and their body is covered by dry and cornified skin, epidermal scales or scutes. They do not have external ear openings."

Duckbilled platypus is oviparous and comes under phylum mammalia. Millipede belongs to the phylum arthropoda. Seaanemone is diploblastic belongs to phylum cnidaria. Silver-fish is an insect belongs to phylum arthropoda, having long antennae, no wings and move in a wiggling motion that resembles the movement of a fish.

In Ctenophora, sexes are not separate. Reproduction takes place only by sexual means. In Cnidaria, which exist in both forms, polyps produce medusae asexually and medusae form the polyps sexually. Porifera (sponge) reproduce asexually by fragmentation and sexually by formation of gametes. Protozoans come under protista which reproduce asexually and sexually by cell fusion and zygote formation.

Line in NCERT: "Reproduction takes place only by sexual means."

Sharks and dogfishes have cylindrical body while skates and rays have flattened body with winglike pectoral fins which are not distinct from body.