31 Years NEET Previous Year Questions: Animal Kingdom - 3 - NEET MCQ

Sponges show cellular grade of organization. They do not have tissue system. Sycon is a sponge.

Presence of diaphragm which separates the thoracic cavity from the abdominal cavity is characteristic feature of all mammals. Homeothermy is the phenomenon whereby  warm blooded animals, birds and mammals can maintain a constant body temperature. Four chambered heart is observed in birds and mammals. Rib cage occurs in all vertebrates

Echinoderms show bilateral  symmetry  in their larval stage and pentamerous radial symmetry in the adult stage. Annelids are bilaterally symmetrical, coelenterates show radial symmetry.  Molluscs are also bilaterally symmetrical.

Insects show a distinct division into head, thorax and abdomen. In crustaceans and myriapods head and thorax are fused. In arachnids body is divided into prothorax, mesothorax and metathorax.

Mammals have 12 pairs of cranial nerves.

Animals belonging to Phylum Porifera are mostly marine except a few which are found in fresh water- e.g. Spongilla, Euspongia.

Platyhelminthes includes flat warms.
There is no body cavity. The animals are therefore acoelomates. Annelids also have bilateral symmetry. They are coelomate having a perivisceral cavity divided into compartments.

Jointed legs & chitinous exoskeleton are the common characters found in centipede, cockroach & crab.

Penguin, Kiwi & Ostrich all belong to class Aves of chordata (i.e. birds) and they do not give birth to their young ones, they are oviparous while Kangaroo, Hedgehog, Dolphin, Loris all belong to class mammalia and are viviparous.

Aurelia, Hydra & Sea anemone have the characteristic cnidoblast cells.

Metameric segmentation means body is divided externally as well as internally. This characteristic is present in annelida (eg. earth worm) and arthropoda (eg. cockroach). Their body is divided externally and internally as well.

Examples of Phyllum mollusca is loligo teredo and octopus because they all have unsegmented body and show bilateral symmetry which are main characteristics of mollusca .

Trypanosoma, Noctiluca, Monocystis & Giardia are unicellular protists i.e. unicellular eukaryotes.

Salamander does not undergo any annual migration as it occurs in Siberian crane, Arctic tern and Salmon mainly for the search of food or for breeding.

Crocodile belongs to reptilia class which has four chambered heart. Lemur teeth are combedded in the sockets of two which is known as thecodont.

Characteristic of phylum-Annelida is pseudocoelomate. Pseudocoelomate is any invertebrate animal whose body cavity is a pseudocoel, a cavity between the gut and the outer body wall derived from a persistent blastocoel, rather than a true coelom. Pseudocoelomate animal include the Rotifera and Nematoda. No, invertebrates do not have a dorsal nerve cord. Instead, invertebrates have a ventral nerve cord.

The correct option is D. 
Cockroach - 10 pairs of spiracles (2 pairs on thorax and 8 pairs on abdomen).
In cockroach, two pairs of spiracles are present in the thoracic region and eight pairs are present in the abdominal region. Spiracles are slit-like apertures through which air enters the body of a cockroach.
In rat, the right kidney is slightly higher in position than the left kidney due to the position of the liver.
In earthworm, the correct sequence of the alimentary canal is pharynx, oesophagus, gizzard, stomach and intestine.
In frog, the body is divisible into the head and trunk. The neck is absent.

Mollusca mostly oviparous and a few viviparous. The development may be direct or indirect with trochophore, velliger and glochidium. 

Ascaris is a common parasite found in the large intestine of man. It is world wide in distribution. The number of worms may be 500 or more in a single host. Ascaris is characterised by presence of neither true coelom nor metamerism. 

The correct option is C 

Scorpion, spider and cockroach belong to the phylum Arthropoda, and have a ventral solid nerve cord. Liver fluke (a flatworm) is bilaterally symmetrical. Sea anemone (a cnidarian) and sea cucumber (an echinoderm) are radially symmetrical. Jointed appendages are characteristic of arthropods and hence, sea urchin (an echinoderm) would not possess them. Metameric segmentation starts with Phylum Annelida, and is present in most higher phyla. Taenia is a flatworm, and does not exhibit metameric segmentation, although the body appears so. Segments of the tapeworm (proglottids) are formed so differently from the segments of groups like Annelids that most zoologists do not admit tapeworms to be metamerically segmented animals.

 Aschelminthes is bilaterally symmetrical and triploblastic. These are mostly aquatic, free living or parasitic. Their body is three layered which is ectoderm, mesoderm and endoderm.

Lampreys and hagfishes are unusual, jawless fish that comprise the order Cyclostomata, so named because of the circular shape of the mouth. The brains of lampreys and hagfishes differ a lot, but they also show a large number of similarities, as do all craniate brains.

Fasciola, a flatworm has a single body cavity to the outside that serves both as mouth for ingestion and anus for egestion of undigested food. This is known as blind sac plan. 

Spongilla is a fresh water sponge that belongs to phylum porifera. It has special collared cells called choanocytes. Choanocytes are not found in leech, dolphin and penguin.

Triploblastic condition can be seen in flat worms. Ctenophores, sponges and corals are diploblastic.