Free Kingdom Animalia MCQs with Answers

111. Metamorphosis of insects is regulated through which hormone?

• A. Pheromone
• B. Thyroxine
• C. Ecdysone
• D. All of these

Explanation: Ecdysone is a steroid hormone, secreted by a pair of prothoracic glands in the thorax of insects and by Yorgans in crustaceans, that stimulates moulting and metamorphosis. In insects, its release is stimulated by prothoracicotropic hormone.

112. The excretory structures of flatworms/Taenia are:

• A. Flame cells
• B. Protonephridia
• C. Malpighian tubules
• D. Green glands

Explanation: Flame cells are scattered throughout the parenchyma from which they remove metabolic wastes. A flame cell is of irregular shape, with granular cytoplasm and a nucleus. The bundle of cilia, or flame, arises from basal granules near the nucleus. Cilia are enclosed into a funnel shaped lumen formed by the terminal blind end of a capillary. Protonephridia are found in flatworms, Malpighian tubules are found in insects and green glands in crustaceans.

113. Bladderworm/cysticercus is the larval stage of:

• A. Tapeworm
• B. Roundworm
• C. Pinworm
• D. Liver fluke

Explanation: Cysticercus is the larval stage of tapeworm which is characterised by a large vesicle and one scolex. Cysticercus develops in adult tapeworm only when ingested by the human host. In the pig's body it leads quite an inactive life and remains viable for several years, after which it dies and becomes calcified. Pork (pig's flesh) containing viable cysticerci is called measly pork because of its spotted appearance.

114. Ecdysis refers to the shedding of the _

• A. Stratum corneum
• B. Epidermis
• C. Dermis
• D. Stratum malpighi

Explanation: The stratum corneum ("the horny layer") is the outermost layer of the epidermis (the outermost layer of the skin). It is composed mainly off dead cells that lack nuclei. In reptiles, the stratum corneum is permanent, and is only replaced during times of rapid growth, in a process called ecdysis or moulting. During ecdysis, small fragments of this layer are periodically shed of from the body. The new layer is regularly formed by underlying stratum germinativum.

115. Malpighian tubules are the _

• A. Excretory organs of insects
• B. Excretory organs of annelids
• C. Respiratory organs of insects
• D. Respiratory organs of annelids.

Explanation: In insects Malpighian tubules are attached to the alimentary canal at the extreme anterior end of hindgut. These are fine, long, unbranched, yellowish and blind tubules lying freely in the haemolymph. These are between 60 to 150 in number and are arranged in 68 bundles. They excrete out nitrogenous wastes from the body in the form of uric acid.

116. Taenia saginata differs from Taenia solium because of the:

• A. Absence of scolex hooks
• B. Absence of scolex hooks and uterine branching
• C. Absence of scolex hooks and presence of both male and female reproductive organs
• D. Presence of scolex hooks

Explanation: The beef tapeworm Taenia saginata is similar to the pork tapeworm Taenia solium, in structure and life history. It is the commonest tapeworm of man with a much greater incidence than that of T. solium. Its intermediate hosts are cattle and buffaloes. It is longer than T.solium, usually attaining a length upto 12 meters or more. Scolex bears four strong, rounded, adhesive suckers but lacks hooks. Strobila comprises of upto 2,000 proglottids. A gravid proglottid contains about 100,000 eggs. Uterus of gravid proglottids has 15 to 35 branches on either side.

117. Eutherians are characterised by:

• A. Hairy skin
• B. True placentation
• C. Ovoviviparity
• D. Glandular skin

Explanation: Eutheria is a taxon containing the placental mammals, such as humans. Nevertheless, all Eutherians are placental mammals. This means that a Eutherian foetus is nourished during gestation by a placenta. Eutherians are also viviparous, meaning that the offspring are carried in the mother's womb until fully developed.

118. The wishbone of birds comes from the:

• A. Pelvic girdle
• B. Skull
• C. Hind limbs
• D. Pectoral girdle/clavicles.

Explanation: The wishbone, known in anatomy as the furcula, is a sternum bone found in birds which is shaped like the letter Y. It is used as an attachment point for the wing muscles. It is so named because of a tradition:Two people pull on each side of such a bone, and when it breaks, the one who gets the larger part is said to have a wish granted. The fork shaped bone is formed from wo clavicles fused with the inter clavicle.

119. Flight muscles of bird are attached to the _

• A. Clavicle
• B. Keel of sternum
• C. Scapula
• D. Coracoid

Explanation: In birds, the pectoral and supracoracoideus muscles that power the wings are anchored to a large bony keel along the midline of the sternum.

120. Which option describes one of the characters of a chordate?

• A. Gills
• B. Spiracles
• C. Postanal tail
• D. Chitinous exoskeleton

Explanation: The diagnostic characters of chordates are notochord, dorsal hollow nerve cord, pharyngeal slits and a post anal tail. The tail is the part of the body behind the cloacal or anal opening. It contains skeletal elements, muscles, blood vessels and nerves but no viscera. It provides much of the propulsive force in aquatic species. The tail is reduced or absent in the adults of some chordates.