144 Questions with Answers and Explanations on “Animal Kingdom” for Biology Students.
1. Animals/organisms floating on the surface of water are
(a) plankton
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(b) pelagic
(c) benthos
(d) neritic.
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Answer and Explanation:
1. (a): Plankton are minute pelagic organisms that drift or float passively with the current in a sea or lake. Plankton includes many microscopic organisms, such as algae, protozoans, various animal larvae, and some worms. Pelagic are the organisms that swim or drift in a sea or a lake. Benthos consists of flora and fauna occurring on the bottom of a sea or lake. Neritic zone is the region of the sea over the continental shelf, which is less than 200 metres deep.
2. Organ Pipe Coral is
(a) Tubipora
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(b) Astraea
(c) Helipora
(d) Fungia.
Answer and Explanation:
2. (a): The common name of Tubipora is organpipe coral. It is a marine animal of the class anthozoa (phylum cnidaria). It occurs on reefs in shallow waters of the Indian and Pacific oceans and is characterized by long, parallel upright polyps or stalks, supported by a skeleton of rigid tubes of calcium carbonate.
3. Silk thread is obtained from silk moth during
(a) pupal stage
(b) larval stage
(c) nymph stage
(d) adult stage.
Answer and Explanation:
3. (b): The mulberry silk moth has been the most commercially important beneficial insect. The silk is obtained by killing the pupa inside the hot water.Then, the silk thread is wound.
4. A wood boring mollusc/Shipworm is
(a) Chiton
(b) Teredo
(c) Umax
(d) Patella.
Answer and Explanation:
4. (b): The common name of Teredo is shipworm which belongs to the class bivalvia of the phylum mollusca. In it, head is absent and foot is wedge – shaped for burrowing. Shell consists oftwo valves. The common name of Chiton is the coat of mail shell (class amphineura), Umax is the grey slug (class gastropoda) and Patella is true limpet (class gastropoda).
5. Association between sucker fish (Remora) and shark is
(a) commensalism
(b) symbiosis
(c) predation
(d) parasitism.
Answer and Explanation:
5. (a): Commensalism is the relationship between individuals of two species of which one is benefited and the other is almost unaffected, i.e., neither benefited nor harmed. Sucker fish (Echeneis, Remora) attaches to the underside of a shark by means of its sucker (modified dorsal fin) located on its head. It rides along fixed to the shark, but occasionally detaches itself long enough to capture the fragments falling off from the shark’s prey. Symbiosis is an interaction in which both the interacting species are benefited. Predation is the interaction between two species, one of which captures, kills and eats up the other. Parasitism is an association of two organisms of different sizes and species in which the smaller one is benefited and the larger one is harmed.
6. Which is not a true amphibian animal?
(a) salamander
(b) toad
(c) tortoise
(d) frog.
Answer and Explanation:
6. (c): Tortoise belongs to the class reptilia. Its body is protected by a shell consisting of a dorsal carpace and ventral plastron.
7. Fire bellied toad is
(a) Amphiuma
(b) Bombina
(c) Necturus
(d) Salamandra.
Answer and Explanation:
7. (b): The fire-bellied toads is a group of eight species of small toads belonging to the genus Bombina. They are found across much of Europe and Asia, staying in water or near the shore. Their name derives from the brightly coloured red or yellow and black patterns on theirventral region, which act as warning to its predators. Amphiuma is a Congo-eel. Necturus is a mud puppy and Salamandra is a salamander.
8. Necturus is
(a) hell bender
(b) congo eel
(c) mud puppy
(d) blind worm.
Answer and Explanation:
8. (c): Necturus is a mud puppy belonging to the order urodela of class Amphibia. Hell bender is a large salamander. Amphiuma is a Congo Eel and lchthyophis is a blind worm.
9. Typhlops is
(a) sea snake
(b) glass snake
(c) blind snake
(d) grass snake.
Answer and Explanation:
9. (c): Typhlops is a genus of blind snakes (non- poisonous snake) found in Europe, Africa, Asia and Central and South America. Sea snake is a poisonous snake while grass snake is a non-poisonous snake. Glass snake is a lizard.
10. Both male and female pigeons secrete milk through
(a) salivary glands
(b) modified sweat glands
(c) crop
(d) gizzard.
Answer and Explanation:
10. (c): Pigeons are noted for their unique ability to produce “pigeon’s milk”, a soft, cheesy and nourishing secretion, especially during the breeding season. It is formed by the degeneration of the epithelial cells lining the err. It is regurgitated into the mouth of the young birds o -II they are old enough to manage a grain-diet like tlu parents. The pigeon’s milk includes water, fat, protein (casein) and lactose. The milk is produced by both sexes and contains 35 per cent of fat.
11. Feet of king fisher are modified for
(a) wading
(b) perching
(c) running
(d) catching.
Answer and Explanation:
11. (a): Hind limbs are variously modified for various functions like perching, grasping etc. In the kingfisher they are modified for wading. The legs and toes are exceptionally long and slender and serve to walk over aquatic vegetation or marshes.
12. Bird vertebrae are
(a) acoelous
(b) heterocoelous
(c) amphicoelous
(d) procoelous.
Answer and Explanation:
12. (b): Bird vertebrae are heterocoelous i.e., the centra of vertebrae have saddle – shaped ends. Acoelous refers to vertebrae that are flat on both ends (mammals). Amphicoelous means both ends of the centrum are concave (fish). Procoelous means concave in front and convex in back (anurans and reptiles).
13.
Hair occur in all mammals except those of
(a) rodentia
(b) chiroptera
(c) primata
(d) cetacea.
Answer and Explanation:
13. (d): Order cetacea includes whales, dolphins and porpoises. These are the most highly modified mammals. They have a fish-like body with smooth, hairless skin devoid of sweat and oil glands, far posterior nares, small eyes, minute ear openings without pinnae, paddle-like forelimbs, no hindlimbs, abdominal testes and flattened tail ending in two horizontal flaps or flukes.
14. Phenomenon of organisms resembling others for escaping from enemies is
(a) adaptation
(b) mimicry
(c) homology
(d) analogy.
Answer and Explanation:
14. (b): Mimicry is resemblance of one species with another in order to obtain advantage, especially, against predation. The species which is imitated is called model while the animal which imitates is known as mimic or mimictic. Model is either ferocious or distasteful to predator. Adaptation is any quality of the organism (morphological, physiological, and behavioral) that enables the organism to survive and reproduce in its habitat. Mimicry is an example of adaption. Homology is the phenomenon in which origin of organs is same but functions are different and analogy is the phenomenon in which origin of organs is different but functions are same.
15. Fish which can be used in biological control of mosquitoes/Larvicidal fish is
(a) Eel
(b) carp
(c) cat fish
(d) Gambusia.
Answer and Explanation:
15. (d): Gambusia is a species of freshwater fish. It is remarkably hardy, surviving in waters of very low oxygen saturations, high salinities and high temperatures. For these reasons, this species may now be the most widespread freshwater fish in the world, having being introduced as a biocontrol in certain countries to control mosquitoes. It feeds on larval and pupal stages of mosquitoes.
16.
Jelly fish belongs to class
(a) hydrozoa
(b) scyphozoa
(c) anthozoa
(d) none of these.
Answer and Explanation:
16. (b): Jelly fish belongs to the class scyphozoa of the phylum cnidaria. Its genus is Aurelia. Amelia is found in the coastal waters of the tropical and temperate seas. Aurelia may float passively or swim actively, singly or in shoals. It is carnivorous and unisexual. Aurelia has a soft, gelatinous, saucer-like body. Its margin bears numerous short tentacles and 8 sense organs, called rhopalia, in notches of the margin. Each sense organ is enclosed by a pair of leaf-like lappets. At the centre of the lower (subumbrellar) surface is the squarish mouth surrounded by 4 long oral arms.
17. Transfer of Taenia to secondary host occurs as
(a) oncosphere
(b) cysticercus
(c) morula
(d) egg.
Answer and Explanation:
17. (a): Eggs of Taenia undergo cleavage to form morula. Morula, at its morphologically posterior end, develops three pairs of chitinous hooks secreted by differentiated cells, called onchoblasts. This six-hooked embryo, called hexacanth, possesses a pair of large penetration glands; it is surrounded by two hexacanth membranes. The hexacanth, together with all the membranes surrounding it, is known as onchosphere.
The secondary or intermediate host acquires infection by ingesting the onchospheres. Pig, which regularly feeds on human excreta is the usual secondary host, but dog, monkey and sheep are also known to get the infection. Man himself may serve as the secondary host by ingesting onchospheres with inadequately cooked or raw vegetables.
18. Photoreceptors of earthworm occur on
(a) clitellum
(b) many eyes
(c) dorsal surface
(d) lateral sides.
Answer and Explanation:
18. (c): Poto-receptors restricted only to dorsal surface, are more numerous on prostomium and peristomium of earthworm and gradually reduce in number towards posterior end of body. They are totally absent in clitellum.
Each photoreceptor consists of a single ovoid cell, with a nucleus and clear cytoplasm containing a network of neurofibrillae and a small transparent L-shaped lens or optic organelle or phaosome, made up of a hyaline substance. Photoreceptors enable worms to judge the intensity and duration of light.
19. Earthworms are
(a) useful
(b) harmful
(c) more useful than harmful
(d) more harmful.
Answer and Explanation:
19. (a): Earthworms are very useful. All over the world they are used as bait for fishing. Earthworms are in general beneficial to agriculture. Their habit of burrowing and swallowing earth increases fertility of soil in many ways.
Their burrows permit penetration of air and moisture in porous soil, improve drainage, and make easier the downward growth of roots. Excretory wastes and other secretions of worms also enrich soil by adding nitrogenous matters that form important plant food.
Earthworms were used variously as medicines in the past. Earthworms were used to cure stones in bladder, yellowness of jaundice, pyorrhoea, piles, rheumatism or gout, diarrhoea. Earthworms are easily obtained and are of convenient size for dissections. They are, therefore, universally employed for class studies and for investigations in general and comparative physiology.
20. A chordate character is
(a) gills
(b) spiracles
(c) post-anal tail
(d) chitinous exoskeleton.
Answer and Explanation:
20. (c): The diagnostic characters of chordates are notochord. dorsal hollow nerve cord, pharyngeal slits and post anal tail. 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 propulsive force in aquatic species. The tail is reduced or absent in the adults of some chordates.
21. Flight muscles of bird are attached to
(a) clavicle
(b) keel of sternum
(c) scapula
(d) coracoid.
Answer and Explanation:
21. (b): In birds, the pectoral and supracoracoideus muscles that power the wings are anchored to a large bony keel along the midline of the sternum.
22. Wish bone of birds is from
(a) pelvic girdle
(b) skull
(c) hind limbs
(d) pectoral girdle/clavicles.
Answer and Explanation:
22. (d): 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. Two clavicles fused with inter clavicle to form a fork shaped bone called wish bone.
23. Eutherians are characterised by
(a) hairy skin
(b) true placentation
(c) ovoviviparity
(d) glandular skin.
Answer and Explanation:
23. (b): 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.
24. Onchosphere occurs in
(a) Ascaris
(b) Fasciola
(c) Taenia
(d) Planaria.
Answer and Explanation:
24. (c): Refer answer 17.
25. Taenia saginata differs from Taenia solium in
(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.
Answer and Explanation:
25. (a): 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 up to 2,000 progiottids. A gravid proglottid contains about 100,000 eggs. Uterus of gravid progiottids has 15 to 35 branches on either side.
26. Pheretima posthuma is highly useful as
(a) their burrows make the soil loose
(b) they make the soil porous, leave their castings and take organic debris in the soil
(c) they are used as fish meal
(d) they kill the birds due to biomagnification of chlorinated hydrocarbons.
Answer and Explanation:
26. (b): Pherelima posthuma is highly useful and beneficial in agriculture. Its habit of burrowing and swallowing earth makes it porous and increases the soil fertility in many ways. Their burrows permit penetration of air and moisture in porous soil and their excretory wastes and other secretions also enrich soil by adding nitrogenous matters to the soil.
Pherelima posthuma is not used as fish meal. Whereas a small white earthworm (Enchytraeus albidus) is often grown in soil and used to feed aquarium fish.
27. Blood of Pheretima is
(a) blue with haemocyanin in corpuscles
(b) blue with haemocyanin in plasma
(c) red with haemoglobin in corpuscles
(d) red with haemoglobin in plasma.
Answer and Explanation:
27. (d): Circulatory or blood vascular system of earthworm is a closed system consisting of blood vessels and capillaries which ramify to all parts of the body. Blood is composed of fluid plasma and colourless corpuscles, physiologically comparable to the leucocytes of the vertebrates. The red respiratory pigment, haemoglobin (or erythrocruorin) occurs dissolved in plasma. It gives a red colour to blood and aids in the transportation of oxygen for respiration.
28. Malpighian tubules are
(a) excretory organs of insects
(b) excretory organs of annelids
(c) respiratory organs of insects
(d) respiratory organs of annelids.
Answer and Explanation:
28. (a): 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 6-8 bundles. These excrete out nitrogenous wastes from the body in the form of uric acid.
29. Kala-azar and Oriental Sore are spread by
(a) housefly
(b) bed bug
(c) sand Fly
(d) fruit Fly.
Answer and Explanation:
29. (c): Visceral leishmaniasis, also known as kala- azar and black fever, is the most severe form of leishmaniasis, a disease caused by parasites of the Leishmania genus.lt is transmitted by sand fly. The adult female sand fly is a bloodsucker, usually feeding at night on sleeping prey. When the fly bites an animal infected with L. donovani, the pathogen is ingested along with the prey’s blood.
Leishmania tropica produces skin ulcers known as oriental sore or Delhi sore. The disease is spread by sand flies. The parasite lives in the endothelial cells of skin capillaries. It leads to ulcerated wounds with raised edges. They do not cause much pain.
30. Penguin occurs in
(a) Australia
(b) Antarctica
(c) Africa
(d) America
Answer and Explanation:
30. (b): Penguins are a group of aquatic, flightless birds living almost exclusively in Antarctica. All penguins are countershaded – that is, they have a white underside and a dark (mostly black) upperside. This is for camouflage.
31. Ecdysis is shedding of
(a) stratum corneum
(b) epidermis
(c) dermis
(d) stratum malpighi.
Answer and Explanation:
31. (a): The stratum corneum (“the horny layer”) is the outermost layer of the epidermis (the outermost layer of the skin). It is composed mainly of 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.
32. Earthworm possesses hearts
(a) 6 pairs
(b) 4 pairs
(c) 2 pairs
(d) 1.
Answer and Explanation:
32. (b): In each of the segments 7, 9, 12 and 13 is found a pair of large, thick, muscular and rhythmically contractile vertical vessels, called hearts. They pump blood from dorsal to ventral vessel, while flow in opposite direction is prevented by internal valves. Hearts of 7th and 9th segments connect dorsal and ventral vessels only and are called lateral hearts. Those of 12th and 13th segments connect both dorsal and supra- oesophageal vessels with ventral vessel, and are designated as latero-oesophageal hearts.
33. Bladderworm/cysticercus is the larval stage of
(a) tapeworm
(b) roundworm
(c) pinworm
(d) liver fluke.
Answer and Explanation:
33. (a): 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 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 for its spotted appearance.
34. The excretory structures of flatworms/ Taenia are
(a) flame cells
(b) protonephridia
(c) malpighian tubules
(d) green glands.
Answer and Explanation:
34. (a): Flame cells are scattered throughout parenchyma from which they remove metabolic wastes. A flame cell is of irregular shape, with granular cytoplasm and a nucleus. Bundle of cilia, or flame, arises from basal granules near 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 in insects and green glands in crustaceans.
35. Classification of Porifera is based on
(a) branching
(b) spicules
(c) reproduction
(d) symmetry.
Answer and Explanation:
35. (b): The phylum Porifera is divided into three classes : calcarea or calcispongiae, hexactinellida or hyalospongiae and demospongiae or Sclerospongiae, on the basis of spicules (skeleton). Class calcarea have calcareous spicules, class hexactinellida have siliceous spicules and class demospongiae have siliceous spicules or spongin fibres or both.
36. Male and female cockroaches can be distinguished externally through
(a) anal styles in male
(b) anal cerci in female
(c) anal style and antennae in females
(d) both B and C.
Answer and Explanation:
36. (a): In male cockroach, 9th sternum bears a pair of short, unjointed thread-like anal styles which are absent in female. Anal cerci and antennae are present in both male and female cockroaches.
37. Metamorphosis of insects is regulated through hormone
(a) pheromone
(b) thyroxine
(c) ecdysone
(d) all of these.
Answer and Explanation:
37. (c): Ecdysone is a steroid hormone, secreted by a pair of prothoracic glands in the thorax of insects and by Y organs in crustaceans, that stimulates moulting and metamorphosis. In insects its release is stimulated by prothoracicotropic hormone.
38. An insect regarded as greatest mechanical carrier of diseases is
(a) Pediculus
(b) Cimex
(c) Musca
(d) Xenopsylla.
Answer and Explanation:
38. (c): Musca is the zoological name of house fly which is regarded as mechanical carrier of many diseases. It is very active and keeps on visiting on dirty things and eatables as well.
39. Which one occurs in echinodermata?
(a) bilateral symmetry
(b) radial symmetry
(c) porous body
(d) soft skin.
Answer and Explanation:
39. (b): Radial symmetry is the arrangement of parts in an organ or organism such that cutting through the centre of the structure in any direction produces two halves that are mirror images of each other. All animals belonging to the cnidaria (e.g. jellyfish) and echinodermata (e.g. starfish) are radially symmetrical.
40. Homeostasis is
(a) tendency to charge with change in environment
(b) tendency to resist change
(c) disturbance in regulatory control
(d) plants and animal extracts used in homeopathy.
40. (b): Homoeostasis is the regulation by an organism of the chemical composition of its body fluids and other aspects of its internal environment so that physiological processes can proceed at optimum rates. It involves monitoring changes in the external and internal environment by means of receptors and adjusting the composition of the body fluids accordingly; excretion and osmoregulation are important in this process. Example of honieostatic regulation are the maintenance of the acid-base balance and body temperature.
41. Kidney of adult rabbit is
(a) pronephros
(b) metanephros
(c) mesonephros
(d) opisthonephros.
Answer and Explanation:
41. (b): Kidney of adult rabbit s metanephros. It is formed from the posterior end of the nephrogenic mesoderm which is displaced somewhat anteriorly and laterally.
42. An egg laying mammal is
(a) kangaroo
(b) platypus
(c) koala
(d) whale.
Answer and Explanation:
42. (b): 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 cm long and well adapted to life in water. Usually 2 eggs are laid at a time. The female curls around them for incubation and remains inactive for about 2 weeks. Newly hatched young ones are exceedingly immature, naked, blind and each 2.5 cm long.
43. The simplest type of canal system in Porifera is
(a) ascon type
(b) leucon type
(c) sycon type
(d) radial type.
Answer and Explanation:
43. (a): Sponges belong to the phylum porifera. Ostia, spongocoel and osculum together form a canal system which is characteristic of all sponges. Canal system of Leticosolenia is of ascon type. It is the simplest type of canal system found in sponges. Water enters directly through ostia into the central spongocoel, which is lined by choanocytes, and leaves through osculum. Sycon type of canal system is found Sycon and Leucon type is found in Spongilla. There is no canal system named as radial type.
44. What is correct about Taenia?
(a) male organs occur in posterior proglottides
(b) male organs occur in anterior proglottides
(c) female organs occur in anterior proglottides
(d) mature proglottides contain both male and female organs.
Answer and Explanation:
44. (d): There are about 450 mature progiottids forming the middle part of strobila. These are large and squarish in outline. The anterior 100 to 150 progiottids contain only male reproductive organs, while the posterior 250 mature progiottids develop both male and female reproductive organs making them hermaphrodite.
45. Ascaris larva is called
(a) cysticercus
(b) rhabditiform
(c) hexacanth
(d) onchosphere.
Answer and Explanation:
45. (b): In Ascaris, rhabditiform larva of first stage is not infective. In a week’s time, it moults within the egg shell and becomes the second stage rhabditoid, which is capable of infecting the host. Cysticercus, hexacanth and onchosphere are the larval stages of Taenia.
46. Assertion: Periplaneta americana is nocturnal, omnivorous, household pets Reason: It is because it acts as scavenger
(a) A is true but R is false
(b) A is false but R is true
(c) Both A and R are true and R is correct explanation of A
(d) Both A and R are true but R is not correct explanation of A.
Answer and Explanation:
46. (d): Cockroaches are found in places where there is warmth, dampness and plenty of organic food to devour. Indoors, they are a common pest in kitchens, latrines, hotels, restaurants, godowns, storerooms, board ships, etc.
Cockroaches are nocturnal creatures. During daytime, they remain inactive and hiding. During night, they show much activity and run here and there in search of food. Being omnivorous and scavengerous in diet, they devour any animal or vegetable substance and even non-living materials like leather, paper, cloth, etc., causing great loss.
47. Sound box of birds is called
(a) pygostyle
(b) larynx
(c) syrinx
(d) synsacrum.
Answer and Explanation:
47. (c): At the posterior end or base of the trachea, at its junction with the bronchi, is found a special structure, the syrinx or voice box, concerned with sound production. It is characteristic of birds as it does not occur in other vertebrates.
48. Adult Culex and Anopheles can be distinguished with the help of
(a) mouth parts/colour
(b) sitting posture
(c) antennae/wings
(d) feeding habits.
Answer and Explanation:
48. (b): Two common mosquito genera, (Anopheles and Culex) can be easily identified by their sitting postures. When sitting, the abdomen of Anopheles is always held at an angle to the surface while that of Culex is held parallel to the surface.
49. Eye of the molluscan group that resembles vertebrate eye is
(a) bivalvia
(b) gastropoda
(c) pelecypoda
(d) cephalopoda.
Answer and Explanation:
49. (d): In Cephalopoda paired eyes are large, efficient and bulge from the dorso-lateral sides of the head. They bear striking resemblance to those of a vertebrate in that; a cornea, iris, lens and retina are present. Lens projects an inverted image on the retina, as in the vertebrate eye.
External muscle attachments enable limited movements; of the eye. But the embryological development of the cephalopod eye is entirely different from that of the vertebrate eye, so that homologically they are different, for the vertebrate eye is formed as an outgrowth of the brain, while the cephalopod eye is formed by an ectodermal invagination.
50. Star Fish belongs to
(a) asteriodea
(c) holothuroidea
(b) ophiuroidea
(d) crinodiea.
Answer and Explanation:
50. (a): Starfishes belong to class Asteroidea, characterized by the presence of five or more arms not sharply set off from a central disc. They are free-living marine animals that occur on sandy or muddy bottoms or crawl about over rocks and shells. All are carnivorous, feeding mainly on crustaceans, polychaetes and molluscs. They also feed on detritus and plankton. They are in general, exhibit remarkable powers of autotomy and regeneration.
51. Aristotle’s lantern occurs in class
(a) echinoidea
(b) asteroidea
(c) holothuroidea
(d) ophiuroidea.
Answer and Explanation:
51. (a): Aristotle’s lantern occurs in the class echinoidea. Five teeth surrounding the mouth are attached to a masticatory apparatus, called Aristotle’s lantern, after its discoverer and because of its resemblance to an ancient Greek ship-lantern. It is situated within the test and projects slightly through the mouth. It consists of five large calcareous plates, called pyramids or alveoli. By means of special protractor and retractor muscles the lantern can be partially protracted and retracted through the mouth. Aristotle’s lantern is used in feeding.
52. Bull Frog of India is
(a) Rana ligrina
(b) R. sylvalica
(c) R. ecutesbeiana
(d) R. esculenla.
Answer and Explanation:
52. (a): The common Indian bull frog Rana tigrina lives in or near permanent freshwater lakes, ponds and streams. It is in the water most of the time. It lives near water mainly for two reasons: (i) To keep skin moist to carry on cutaneous respiration, and (ii) To immediately jump or slip into water to escape from enemies.
53. What is common in whale, bat and rat?
(a) absence of neck
(b) muscular diaphragm between thorax and abdomen?
(c) extra-abdominal testes to avoid high temperature of body
(d) presence of external ears.
Answer and Explanation:
53. (b): Whale, bat and rat are mammals. Diaphragm is present in mammals. The diaphragm separates the thoracic cavity (with lung and heart) from the abdominal cavity (with digestive system and urogenital system). In its relaxed state, the diaphragm is shaped like a dome. It is controlled by the phrenic nerve.
54. Gorilla, chimpanzee, monkeys and humans belong to the same
(a) species
(b) genus
(c) family
(d) order.
Answer and Explanation:
54. (d): Gorilla, chimpanzee, monkeys and humans belong to the same order i.e. primates. They have well developed brain, flat nails on fingers and toes. First digit is usually opposable, an adaptation for grasping. Eyes are typically large and turned forward.
55. Mucus helps frog in forming
(a) thick skin
(b) dry skin
(c) smooth skin
(d) moist skin.
Answer and Explanation:
55. (d): Mucus helps frog in forming moist skin as skin is its respiratory organ.
56. A larval stage occurs in the life history of all members of the group
(a) frog, lizard and cockroach
(b) Ascaris, housefly and frog
(c) housefly, earthworm and mosquito
(d) butterfly, frog and mosquito.
Answer and Explanation:
56. (d): In butterfly, the larval stage is known as catterpillar, in frog is known as tadpole and in mosquito is known as wriggler.
57. Tracheae of cockroach and mammal are similar in having
(a) paried nature
(b) noncollapsible walls
(c) ciliated inner lining
(d) origin from head.
Answer and Explanation:
57. (b): Tracheae act as passage of air during respiration in both cockroach and mammals. In cockroach, the cuticular lining is spirally thickened forming taenidia which prevents the tracheal tubes from collapsing. In mammals, cartilaginous rings supporting the walls of the tracheae prevent their collapsing.
58. Budding is a normal mode of asexual reproduction in
(a) starfish and Hydra
(b) Hydra and sponges
(c) tapeworm and Hydra
(d) sponge and starfish.
Answer and Explanation:
58. (b): Budding is an asexual mode of reproduction in hydra and sponges. Bud is formed as an outgrowth on the body surface, then detached to form new animal.
59. Which one of the following animals possesses nerve cells but no nerves?
(a) Hydra
(b) tapeworm
(c) earthworm
(d) Frogs tadpole.
Answer:
(a) Hydra
60. What is true about Taenia saginata?
(a) life history has pig as intermediate host
(b) there are two large suckers on scolex
(c) rostellar hooks are absent
(d) rostelium has double circle of hooks.
Answer and Explanation:
60. (c): 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. Scolex bears four strong, rounded, adhesive suckers but lacks hooks and rostellum.
61. Which one assists in locomotion?
(a) trichocysts in Paramecium
(b) pedicellariae of star fish
(c) clitellum in Pheretima
(d) posterior sucker in Hirudinaria.
Answer and Explanation:
61. (d): The looping or crawling movement in Hirudinaria is performed with the help of muscles and suckers which serve for attachment.
62. Which is common between ostrich, penguin and kiwi?
(a) running birds
(b) migratory birds
(c) flightless birds
(d) four toed birds.
Answer and Explanation:
62. (c): The Ostrich is a flightless bird native to Africa. It is the only living species of its family. It is distinctive in its appearance, with a long neck and legs and the ability to run at speeds of about 65 km/h (40 mph), the top land speed of any bird. Penguins are a group of aquatic, flightless birds living almost exclusively in the Southern Hemisphere. A kiwi is any of the species of small flightless birds endemic to New Zealand.
63. Which of the following does not have an open circulatory system?
(a) frog’s tadpole
(b) prawn
(c) C.helifer
(d) cockroach.
Answer and Explanation:
63. (a): In the open circulatory system, the blood is not confined to the blood vessels, but it flows in the open spaces. Prawn, Chelifer and cockroach have open circulatory system. Frog’s tadpole has closed circulatory system, that is the blood flows in the blood vessels.
64. In man and mammals, air passes from outside into the lungs through
(a) nasal cavity, larynx, pharynx, trachea, bronchi, alveoli
(b) nasal cavity, larynx, pharynx, trachea, bronchioles, alveoli
(c) nasal cavity, pharynx, larynx, trachea, bronchioles, bronchi, alveoli
(d) nasal cavity, pharynx, larynx, trachea, bronchi, bronchioles, alveoli.
Answer and Explanation:
64. (d): Air passes from the external nares into the nasal cavity where the dust particles are trapped. From nasal cavity, the air moves into pharynx which is a short, vertical tube. It further leads into two tubes, trachea and oesophagus. Larynx is the upper part of trachea. Besides forming a part of the respiratory tract, it also serves as the voice box. Trachea is a thin walled tube that extends downward through the neck. It divides into two primary bronchi which on entering the lungs divide into fine branches called bronchioles which enter the alveoli. Exchange of gases occurs in alveoli.
65. Two examples in which the nitrogenous wastes are excreted from body in the form of uric acid are
(a) birds and lizards
(b) frogs and cartilaginous fish
(c) insects and bony fish
(d) mammals and molluscs.
Answer and Explanation:
65. (a): Birds and lizards are uricotelic. Uricotelic animals are those that excrete nitrogenous waste in the form of uric acid. It is being insoluble in water, does not require water for its elimination. Frogs and cartilaginous fish are ureotelic, that is they excrete nitrogenous waste in the form of urea. The main excretory matter of insects is uric acid and of bony fish is ammonia (ammoniotelic). Molluscs may be ammoniotelic or uricotelic. Mammals are ureotelic (excretory matter is urea).
66. Tube feet are the characteristic structures of
(a) starfish
(b) jellyfish
(c) crayfish
(d) cuttlefish.
Answer and Explanation:
66. (a): Starfish belongs to the phylum echinodermata who have developed tube feet for locomotion. The tube feet generally protrude out through special radial areas called ambulacra. They are extended and retracted by variations in hydraulic pressure of fluid in them and by contractions of their muscles.
Cuttle fish belongs to the phylum mollusca and it swims. Crayfish belongs to the phylum arthropoda in which locomotion occurs by jointed appendages. Jelly fish belongs to the phylum cnidaria and it swims.
68. Which of the following is an example of platyhelminthes?
(a) Plasmodium
(b) Schistosoma
(c) Trypanosoma
(d) Wuchereria.
Answer and Explanation:
68. (b): Platyhelminthes have soft and dorsoventrally flattened body with bilateral symmetry. Plasmodium and Trypanosoma belong to phylum protozoa while Wuchereria belongs to phylum aschelminthes.
69. Radial symmetry is, usually, exhibited in animals which
(a) are attached to the substratum
(b) have one opening of alimentary canal
(c) live in water
(d) have ciliary mode of feeding.
Answer and Explanation:
69. (a): The organisms attached to the substratum possess radial symmetry in all vertical planes. All the animals belonging to cnidaria (e.g. jellyfish) and echinodermata (e.g. starfish) are radially symmetrical and typically sessile in their adult form. In radial symmetry the parts in an organ or organism when cut through the centre in any direction produces two halves that are mirror images of each other.
70. One of the special characters of coelenterata only is the occurrence of
(a) polymorphism
(b) flame cells
(c) hermaphroditism
(d) nematocysts.
Answer:
(d) nematocysts.
71. A common characteristic of all vertebrates without exception is
(a) the division of body into head, neck, trunk and tail
(b) their body covered with an exoskeleton
(c) the possession of two pairs of functional appendages
(d) the presence of well-developed skull.
Answer and Explanation:
71. (d): The sub-phylum vertebrata or craniata have a well developed central nervous system that is differentiated into brain and spinal cord. Brain is protected by a brain box called cranium, so they are also called as craniata.
72. The oestrous cycle is a characteristic of
(a) human females only
(b) mammalian females other than primates
(c) human males only
(d) mammalian males other than primates.
Answer and Explanation:
72. (b): Oestrous cycle comprises cyclic changes in female reproductive system of non-primate mammals like cows, dogs, etc. The oestrous cycle consists of a short period of oestrous or ‘heat’ (e.g., 18 hours in cow) followed by the rest of period of anoestrous or ‘passive’. During oestrous, the female receives the male for copulation. During anoestrus, the female becomes passive and does not receive the male. Although the breakdown of tissues takes place in the female reproductive tract at the end of an oestrous cycle, yet there is no menstruation.
73. The sympathetic nerves, in mammals, arise from
(a) sacral nerves
(b) 3rd, 7th, 9th and 10th cranial nerves
(c) thoraco-lumbar nerves
(d) cervical nerves.
Answer and Explanation:
73. (c): Sympathetic nervous system forms a part of autonomic nervous system that consists of nerves which connect the visceral receptors and effectors with the central nervous system through the crania and spinal nerves. Sympathetic nerves arise from thoracolumbar nerves.
74. The organisms attached to the substratum, generally, possess
(a) one single opening of the digestive canal
(b) cilia on the surface to create water current
(c) radial symmetry
(d) asymmetrical body.
Answer and Explanation:
74. (c): Refer answer 69.
75. The function of contractile vacuole, in protozoa, is
(a) osmoregulation
(b) reproduction
(c) locomotion
(d) digestion of food.
Answer and Explanation:
75. (a): The function of contractile vacuole is osmoregulatory. Water in freshwater protozoa enters the organism by endosmosis and during feeding. If the organism does not possess a mechanism to get rid of this excess water, it will swell to the point of rupture and dissolution. The mechanism which is assumed to effect water regulation is the contractile vacuole. The vacuole periodically increases in volume (diastole) to get filled with water and contracts (systole) to discharge its water content to the surrounding environment.
76. Besides annelida and arthropoda, the metamerism is exhibited by
(a) mollusca
(b) acanthocephala
(c) cestoda
(d) chordata.
Answer and Explanation:
76. (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.
77. Which of the following or gins possesses characteristics of a plant and an animal?
(a) Euglena
(b) Paramecium
(c) bacteria
(d) Mycoplasma.
Answer and Explanation:
77. (a): Euglena possesses the characteristics of both plant and animal. It has chlorophyll, thus it is autotrophic like plants. In contrast to this, it has flagellated locomotion like animals.
78. The formation of canal system in sponges is due to
(a) folding of inner walls
(b) gastro-vascular system
(c) reproduction
(d) porous walls.
Answer and Explanation:
78. (d): The body wall of sponges encloses a large cavity, the spongocoel and in most cases also contains in its thickness numerous small cavities, the canals. Either the spongocoel or certain canals are lined by choanocytes with flagella.
The ceaseless beating of flagella maintains a steady current of water through the canals in the sponge body. The current of water enters through small pores, the dermal ostia, perforating the porocytes and, after passing through various canals, enters the spongocoel, and finally leaves through a larger aperture, the osculum, or apertures, the oscula.
All the cavities in a sponge body are intercommunicating, and are collectively referred to as the canal system. The current of water that flows through the canal system brings in food and oxygen, and carries away carbon dioxide and nitrogenous waste materials. Thus, the canal system helps the sponge in nutrition, respiration and excretion.
79. Which of the following is common among mammals?
(a) they undergo no moulting
(b) they have seven cervical vertebrae
(c) they are carnivores
(d) they have ventral nerve cord.
Answer and Explanation:
79. (a): Mammals do not undergo moulting. Moulting is usually exhibited by invertebrates. In many vertebrate species, cervical vertebrae are variable in number, however almost all mammals have seven cervical vertebrae including those with short neck such as elephants or whales and those with very long necks, such as giraffes. But there are a few exceptional cases in which there are nine cervical vertebrae in mammals. Mammals have dorsal nerve cord. All the mammals are not carnivorous; they may be herbivorous, carnivorous and omnivorous also.
80. The nephridia in earthworm are analogous to
(a) nematoblasts of Hydra
(b) flame cells of Planaria
(c) gills of Prawn
(d) trachea of insects.
Answer and Explanation:
80. (b): Analogous organs are organs of very disparate organisms and are superficially similar but have evolved from vastly different origins. They have same function but different structure. The nephridia in earthworm are analogous to flame cells of Planaria since both of them have excretory functions. Nematoblasts of Hydra are organs of locomotion, food capture and anchorage. Gills and trachea are organs of respiration in prawn and insects respectively.
81. Pneumatic bone is found in
(a) shark
(b) Rana
(c) pigeon
(d) whale.
Answer and Explanation:
81. (c): Pneumatic bone is present in pigeon to keep the bones light weight because the pigeon has to fly. Pneumatic bone has a hollow cavity, which makes k light.
82. Coelom is found between
(a) body wall and ectoderm
(b) ectoderm and endoderm
(c) mesoderm and body wall (endoderm)
(d) mesoderm and ectoderm.
Answer and Explanation:
82. (c): Coelorn is a fluid-filled cavity that forms the main body cavity of vertebrate and most invertebrate animals. It is found between mesoderm and body wall (endoderm).
83. When an animal has both the characters of male and female, it is called
(a) super female
(b) super male
(c) intersex
(d) gynandromorph.
Answer and Explanation:
83. (d): Gynandromorph is an animal that possesses both male and female characteristics because it is genetically a mosaic, i.e. some of its cells are genetically male and others are female. This phenomenon is found particularly in the insects but also appears in the birds and mammals; it is often due to the loss of an X chromosome in a stem cell of a female (XX), so that all tissues derived from that cell are phenotypically male.
Intersex is an organism displaying characteristics that are intermediate between those of the typical male and typical female of its species. For example, a human intersex may have testes that fail to develop, so that although he is technically a man he has the external appearance of a woman.
In super female and super male the number of female and male sex chromosomes, respectively, is above normal.
84. Which of the following statements is without exception for sponges?
(a) they all have calcareous spicules
(b) they have high regenerative power
(c) they are found only in marine water
(d) they are all radially symmetrical.
Answer and Explanation:
84. (b): Sponges may have calcareous or siliceous spicules. All sponges are not marine, some are freshwater living also. Sponges may be asymmetrical or bilaterally symmetrical, besides being radially symmetrical. So, these characters are with exception. The character without exception is the regenerative power of sponges.
All sponges have a good power of regeneration. They can regrow any part of the body lost or cut off. Small fragments can grow into a complete sponge.
85. The embryonated egg of Ascaris represents
(a) an egg with blastula
(b) an egg with a juvenile
(c) an egg with an egg
(d) an egg with gastrula.
Answer and Explanation:
85. (b): The embryonated egg of Ascaris represents an egg with a juvenile. In case of Ascaris, the eggs containing the second stage of juvenile are called embryonated egg. These are infective to human host. In suitable conditions of temperature and moisture these eggs can survive for 5 to 6 years in the soil.
86. The kidney of an adult frog is
(a) metanephros
(b) opisthonephros
(c) pronephros
(d) mesonephros.
Answer and Explanation:
86. (d): Mesonephros kidney is present in both adult as well as embryo of frog. A mesonephros develops from the middle part of intermediate mesoderm, posterior to each pronephros soon after its degeneration.
87. In frog, “fenestra ovalis” is
(a) the communication between the pharynx and the tympanic cavity
(b) the external opening of the tympanic cavity which is covered by the tympanic membrane
(c) the air filled cavity of the middle ear
(d) the opening in the auditory capsule which separates the middle ear from the internal ear.
Answer and Explanation:
87. (c): The bony partition between tympanic cavity (cavity of middle ear) and auditory capsule (internal ear) is perforated by a small window-like oval aperture, the fenestra ovalis, which remains closed by a membrane and a cartilaginous nodule, the stapedial plate.
88. In frog, the surface of attachment of tongue is
(a) pterygoid
(b) hyoid apparatus
(c) parasphenoid
(d) palatine.
Answer and Explanation:
88. (b): In adult frog, gills disappear and their skeletal framework is also reduced to form hyoid apparatus. It lies below tongue in the floor of mouth and provides surface of attachment to the tongue.
Pterygoid contributes to the postero-ventral margin of orbit of its side. Palatine connects the anterior side of cranium with the middle of maxilla. Parasphenoid forms floor of the cranium.
89. The roof of the cranium of frog is formed by
(a) frontoparietal
(b) orbitosphenoid
(c) parasphenoid
(d) alisphenoid.
Answer and Explanation:
89. (a): Fronto-parietals are a pair of long, broad, flattened and membranous bones. They are united along the mid-dorsal line and form the whole roof of cranium. In larval frog, each fronto-parietal occurs into separate frontal and parietal parts, but in adult frog, they become fused to form a single frontoparietal. The entire floor of cranium is covered and strengthened by a large parasphenoid bone.
90. What is common among silverfish, scorpion, crab and honey bee?
(a) jointed legs
(b) metamorphosis
(c) compound eyes
(d) poison glands.
Answer and Explanation:
90. (c): Silver fish, scorpion, crab and honey bee all have compound eyes. These are present on each lateral side of the head and are convex. This eye consists of numerous visual units, the ommatidia. Each ommatidium consists of an outer cuticle covering lenses, beneath which are 6-8 retinal cells surrounding a light sensitive rhabdom. Adjacent ommatidia are separated by pigment cells.
91. Which one of the following cells, found in testes of rabbit, secretes male hormone?
(a) epithelial cells
(b) spermatocytes
(c) Leydig’s cell
(d) Sertoli cells.
Answer and Explanation:
91. (c): The connective tissue in between the seminiferous tubules of the testis contains special interstitial cells or cells of Leydig. They secrete the male sex hormones (androgens) such as testosterone. It stimulates secondary sexual characteristics of the male such as the enlargement of the external genitals and accessory glands.
92. The lower jaw in mammals is made up of
(a) dentary
(b) maxills
(c) angulars
(d) mandible.
Answer and Explanation:
92. (a): Dentary is a membrane bone, present in the lower jaw of the vertebrates, that supports the teeth. In mammals the dentary is the sole bone of the lower jaw. The dentary bone is relativley short comma shaped bone.
93. Most appropriate term to describe the life cycle of Obelia is
(a) metamorphosis
(b) neoteny
(c) metagenesis
(d) all of these.
Answer and Explanation:
93. (c): Obelia belongs to the phylum coelenterata. In Obelia, life-cycle includes two clearly defined phases:
A fixed polypoid phase (hydroid colony) and a pelagic medusoid phase. Hydroid colony has no gonads and reproduces by asexual budding to give rise to medusae. On the other hand, medusae reproduce exclusively by sexual method (ova and sperms) to give rise to new hydroid colonies. This fact apparently seems to have given rise to the idea of alternation of generations, also called metagenesis.
94. Solenocytes are the main excretory structures in
(a) echinodermates
(b) platyhelminthes
(c) annelids
(d) molluscs.
Answer and Explanation:
94. (b): Solenocytes are also called flame cells. It is a cup shaped cell, which contains group of cilia and this is the main excretory organ of platyhelminthes.
95. The long bones are hollow and connected by air passages. They are the characteristics of
(a) reptilia
(b) land vertebrates
(c) aves
(d) mammals.
Answer and Explanation:
95. (c): Aves are the animals that fly so their body weight should be less and for this their bones are hollow and connected by air passages. Reptilia, land vertebrates and mammals do not have hollow bones.
96. Which of the following is not found in birds?
(a) pelvic girdle
(b) pectoral girdle
(c) hind limb
(d) for limb.
Answer and Explanation:
96. (d): Fore limbs are absent in birds as they are modified into wings for flight. They are attached high on the back, to the anterior or thoracic region of the trunk, and are very powerful when compared with the size and strength of the bird. Each wing is elongated, flattened and distally pointed with its longitudnal axis at right angles to that of the trunk. Hind limb is made of three parts – thigh, shank and foot. Pectoral girdle on each side consists of three bones – a large coracoid, scapula and clavicle. Pelvic girdle consists of ilium, ischium and pubis.
97. The canal system is a characteristic feature of
(a) echinoderms
(b) sponges
(c) helminthes
(d) coelenterates.
Answer and Explanation:
97. (b): Refer answer 78.
98. Temperature changes, in the environment, affect most of the animals which are
(a) poikilothermic
(b) honioiothermic
(c) aquatic
(d) desert living.
Answer and Explanation:
98. (a): Poikilothermic animals are those whose body temperature varies with the temperature of the environment. All animals except birds and mammals are poikilothermic. Although unable to maintain a constant body temperature, they can respond to compensate for very low or very high temperatures.
For example, the tissue composition (especially cell osmotic pressure) can change to regulate the blood flow to peripheral tissues (and thus increase heat loss or heat absorption), and the animals can actively seek sun or shade. Homoiothermic animals are those whose body temperature remains constant irrespective of the variations in the temperature of the environment.
99. Aquatic reptiles are
(a) ureotelic
(b) Ureotelic in water
(c) ammonotelic
(d) ureotelic over land
Answer and Explanation:
99. (b): The waste material of aquatic reptiles chiefly consists of urea, so they are ureotelic. Land forms are uricotelic i.e., their water material consists of uric acid.
100. What is true for mammalia?
(a) Platypus is oviparous
(b) bats have feather
(c) elephant is ovoviviparous
(d) diaphragm is absent in them.
Answer and Explanation:
100. (a): Mammals are viviparous i.e. they give birth to young ones. Protherians (e.g., Platypus) are primitive mammals and lay eggs, so they are oviparous.
101. Which of the following characters is absent in all chordates?
(a) diaphragm
(b) coelom
(c) pharyngeal gill clefts
(d) dorsal nerve cord.
Answer and Explanation:
101. (a): Diaphragm is a membrane that separates thoracic cavity from abdominal cavity. It is present only in mammals. All other chordates do not have diaphragm as their body cavity is not divided into thoracic and abdominal cavities. Chordates are coelomate animals having a true coelom, entercoelicand shizocoelic in origin. Pharyngeal gill slits are present at some stage, may or may not be functional. Nerve cord is dorsal and tubular.
102. What happens if bone of frog is kept in dilute hydrochloric acid
(a) will become flexible
(b) will turn black
(c) will break into pieces
(d) will shrink.
Answer and Explanation:
102. (a): Main component of bone is collagen which is a complex combination of amino acids. When frog’s bone is treated with HC1, these compounds are broken down and the bone becomes flexible.
103. Similarity in Ascaris himbricoides and Anopheles stephensi is
(a) sexual dimorphism
(b) metamerism
(c) anaerobic respiration
(d) endoparasitism.
Answer and Explanation:
103. (a): Sexual dimorphism is the difference in the form of individuals of different sexes but of same species. Sexes in Ascaris are separate and sexual dimorphism is well defined. Males are smaller than females. They possess a recurved tail with pre and post anal papillae, a cloaca, and a pair of spicules or penial setae. In Anopheles, the ends of maxillary palps in males are club-shaped while in females they are not.
104. Primary function of enteronephric nephridia of Pherelima is
(a) osmoregulation
(b) excretion of nitrogenous wastes
(c) respiration
(d) locomotion.
Answer and Explanation:
104. (a): Pharyngeal nephridiaand septal nephridiaare enteronephric as they discharge excretory matter into the gut. Discharge of waste matter via gut is an adaptation to conserve water by its reabsorption in the gut. Integumentary nephridra are exonephric, as they discharge waste matter to the exterior.
105. Which of the following animals have scattered cells with cell – tissue grade organization?
(a) sponge
(b) Hydra
(c) liver fluke
(d) Ascaris.
Answer and Explanation:
105. (b): Hydra, has tissue level of organization, its body is multicellular and the cells occur in 2 distinct layers or tissues of specialized cells. Sponges have cellular level of organization. Liver fluke and Ascaris have organ- system level of organization.
106. Cleavage in mammals is
(a) holoblastic equal
(b) holoblastic unequal
(c) superficial
(d) discoidal.
Answer and Explanation:
106. (b): Cleavage in mammals is holoblastic unequal. Mammals have microlecithal eggs so they have holoblastic cleavage in which the segmentation lines pass through the entire egg, dividing it completely. As the eggs are microlecithal so one would expect that first cleavage will produce two equal blastomeres. But, this is not the case. The two blastomeres produced are unequal which divide further to form 4 unequal blastomeres and this process continues to form a ball of cells called morula. Superficial cleavage occurs in insects and discoidal cleavage occurs in birds.
107. In Hydra, waste material of food digestion and nitrogenous waste material are removed respectively from
(a) mouth and mouth
(b) body wall and body wall
(c) mouth and body wall
(d) mouth and tentacles.
Answer and Explanation:
107. (c): In Hydra indigestible residues are egested through mouth, for there is no anus. Egestion occurs by a sudden squirt due to muscular contraction of body, so that the debris is thrown at a distance. Hydra has neither blood and blood vessels, nor organs of excretion.
Due to thinness of body wall and circulation of water in gastrovascular cavity, most cells of body remain freely exposed to the surrounding water. Therefore, excretion of waste nitrogenous matter (chiefly ammonia) occurs directly by diffusion through cell membranes in the outside world.
108. In which of the following animals post anal tail is found.
(a) earthworm
(b) lower invertebrates
(c) scorpion
(d) snake.
Answer and Explanation:
108. (d): Snakes are limbless reptiles with elongated cylindrical body, covered with overlapping scales differentiated into shields and plates and have post anal tail which is long.
109. In which of the following animals, haemocyanin pigment is found
(a) annelid
(b) echinodermata
(c) insecta
(d) mollusca.
Answer and Explanation:
109. (d): In molluscs, blood often has a copper- containing, blue respiratory pigment called haemocyanin. In insects, the blood called haemolymph is colourless. In echinodermates, blood is colourless as it has no respiratory pigment. In annelids, the blood is red with haemoglobin dissolved in plasma.
110. In protozoa like Amoeba and Paramecium, the organ for osmoregulation is
(a) contractile vacuole
(b) mitochondria
(c) nucleus
(d) food vacuole.
Answer and Explanation:
110. (a): Refer answer 75.
111. In which of the following, notochord is present in embryonic stage?
(a) all chordates
(b) some chordates
(c) vertebrates
(d) non chordates.
Answer and Explanation:
111. (a): Chordates are the animals that have notochord, a skeletal rod present at some stage in life cycle. In lower vertebrates, notochord persists throughout life while in higher vertebrates it is replaced by vertebral column in adults. Nonchordates never develop notochord, not even in embryonic stage.
112. In which of the following animals dimorphic nucleus is found
(a) Amoeba proteus
(b) Trypanosoma gambiense
(c) Plasmodium vivax
(d) Paramecium caudatum.
Answer and Explanation:
112. (d): Dimorphic nucleus means two types of nuclei are present in P. caudatum -large macronucleus and small micronucleus. The macronucleus is roughly kidney- shaped and with inconspicuous nuclear membrane. Macronucleus is the somatic or vegetative nucleus and controls the day-to-day metabolic activities of the cell.
The micronucleus is lodged in a depression on the surface ofthe macronucleus. It is usually spherical, with a nuclear membrane and with diploid number of chromosomes. It controls the reproductive activities of the organism. Amoeba, Trypanosoma and Plasmodium have only one nucleus.
113. In which of the following animal’s nerve cell is present but brain is absent?
(a) sponge
(b) earth-worm
(c) cockroach
(d) Hydra.
Answer and Explanation:
113. (d): Hydra which belongs to the phylum coelenterata has nerve cells but no brain. Its nervous system consists of nerve cells and their processes. Sensory cells are also present. Sponges do not have nerve cells, they lack nervous system. Earthworm (annelida) has nervous system consisting of a circumenteric nerve ring and a solid, double, midventral nerve cord with ganglia. Cockroach (arthropoda) has the nervous system as that of earthworm.
114. Given below are four matchings of an animal and it’s kind of respiratory organ:
(A) Silver fish
(B) Scorpion
(C) Sea squirt
(D) Dolphin
The correct matching’s are
(a) A and B (b) A, B and C
(c) B and D (d) C and D
Answer and Explanation:
114. (b): Silver fish is an insect in which respiration occurs by tracheae. These communicate with the exterior by paired apertures, called spiracles. Respiratory system of scorpion consists of 4 pairs of book lungs that communicate with the outer air through stigma. In sea squirt, respiration occurs through pharyngeal slits. In dolphin, respiration occurs by lungs.
115. Which one of the following is a matching pair of an animal and a certain phenomenon it exhibits?
(a) Pherelima – Sexual dimorphism
(b) Musca – Complete metamorphosis
(c) Chameleon – Mimicry
(d) Taenia – Polymorphism
Answer and Explanation:
115. (b): In Musca, development is indirect with complete metamorphosis (holometaboly) including four stages as follows – egg, larva, pupa and adult.
In complete metamorphosis, 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 to a mature form.
116. Ommatidia serve the purpose of photoreception in
(a) cockroach
(b) frog
(c) humans
(d) sunflower
Answer and Explanation:
116. (a): In cockroach, the compound eyes are a pair of large, black, kidney-shaped organs situated dorsolateral on the head, one on either side. Their surface is marked by a large number of hexagonal areas, the facets. Each facet represents a visual unit named ommatidium. The eyes are the organs of sight (photoreception).
117. During the life-cycle, Fasciola hepatica (liver fluke) infects its intermediate host and primary host at the following larval stages respectively
(a) redia and miracidium
(b) cercaria and redia
(c) metacercaria and cercaria
(d) miracidium and metacercaria
Answer and Explanation:
117. (d): Life cycle of F.hepatica is complete and completed in two hosts. Primary host, in which the adult fluke lives, is sheep. While the intermediate host, in which numerous larval stages are passed, is a snail (Lymnaea, Planorbis, etc.).
This type of life cycle, involving two different kinds of hosts, is termed digenetic. Miracidium larva is the larval stage involved in life cycle. When suitable conditions become available, the encapsulated embryo, in 4-15 days, differentiates into a miracidium larva.
It hatches out and swims in water. Metacercaria develops into adult fluke only inside its definitive host or sheep. The latter gets infection by grazing on leaves and grass blades to which the cysts are attached. Metacercaria survives action of host’s gastric juice as its cyst is insoluble in it. Cyst wall finally dissolves in proximal part of intestine and liberates the larva.
118. Sycon belongs to a group of animals, which are best described as
(a) unicellular or acellular
(b) multicellular without any tissue organization
(c) multicellular with a gastrovascular system
(d) multicellular having tissue organization, but no body cavity (2003)
Answer and Explanation:
118. (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.
119. Systemic heart refers to
(a) the heart that contracts under stimulation from nervous system
(b) left auricle and left ventricle in higher vertebrates
(c) entire heart in lower vertebrates
(d) the two ventricles together in humans
Answer and Explanation:
119. (c): Systemic heart refers to the entire heart of lower vertebrates. This heart pumps blood to body parts and not the lungs.
120. The chief advantage of encystment of an Amoeba is
(a) the ability to survive during adverse physical conditions
(b) the ability to live for some time without ingesting food
(c) protection from parasites and predators
(d) the chance to get rid of accumulated waste products
Answer and Explanation:
120. (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.
121. Bartholin’s glands are situated
(a) on the sides of the head of some amphibians
(b) at the reduced tail end of birds
(c) on either side of vagina in humans
(d) on either side of vas deferens in humans
Answer and Explanation:
121. (c): Bartholin’s glands are situated on either side of vagina in humans (females). These glands secrete a fluid that lubricates the vulva during copulation.
122. When a fresh-water protozoan possessing a contractile vacuole, is placed in a glass containing marine water, the vacuole will
(a) increase in number
(b) disappear
(c) increase in size
(d) decrease in size.
Answer and Explanation:
122. (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 hypotonic solution. Water will enter into contractile vacuole, thus increasing its size and ultimately it will burst and disappear.
123. One of the following is a very unique feature of the mammalian body
(a) homeothermy
(b) presence of diaphragm
(c) four chambered heart
(d) rib cage.
Answer and Explanation:
123. (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.
124. Uricotelism is found in
(a) mammals and birds
(b) fish and fresh water protozoans
(c) birds, land reptiles and insects
(d) frogs and toads.
Answer and Explanation:
124. (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 very dry terrestrial environment as adult organisms. Uric acid is discharged as thick paste or as solid pellet. Egs. terrestrial reptiles, birds, insects, gastropod mollusc etc.
125. Presence of gills in the tadpole of frog indicates that
(a) fish were amphibious in the past
(b) fish evolved from frog-like ancestors
(c) frogs will have gills in future
(d) frogs evolved from gilled ancestors.
Answer and Explanation:
125. (d): It is universally accepted that amphibians (frogs) have originated from fishes. 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 air, both usually lay eggs in water.
126. The animals with bilateral symmetry in young stage, and radial pentamerous symmetry in the adult stage, belong to the phylum
(a) annelida
(b) mollusca
(c) cnidaria
(d) echinodermata.
Answer and Explanation:
126. (d): Echinoderms are triploblastic animals with organ system level of organisation. Larval forms possess bilateral symmetry while adults have radial symmetry.
127. In Arthropoda, head and thorax are often use to form cephalothorax, but in which one of the following classes, is the body divided into head thorax and abdomen?
(a) insecta
(b) myriapoda
(c) crustacea
(d) arachnida and curstacea.
Answer and Explanation:
127. (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 arthropoda phylum have body divided into head, thorax and abdomen.
128. Which one of the following characters is not typical of the class mammalia?
(a) thecodont dentition
(b) alveolar lungs
(c) ten pairs of cranial nerves
(d) seven cervical vertebrae.
Answer and Explanation:
128. (c): Mammals have twelve pair of cranial nerves. Ten pairs of cranial nerves are present in fish and amphibians. Reptiles and birds also have 12 pairs of cranial nerves.
129. Which of the following unicellular organisms has a macronucleus for trophic function and one or more micronuclei for reproduction?
(a) Euglena
(b) Amoeba
(c) Paramecium
(d) Trypanosoma.
Answer and Explanation:
129. (c): Refer answer 112.
130. From the following statements select the wrong one.
(a) prawn has two pairs of antennae.
(b) nematocysts are characteristics of the phylum cnidaria.
(c) millepedes have two pairs of appendages in each segment of the body.
(d) animals belonging to phylum porifera are marine and fresh water.
Answer and Explanation:
130. (a): Prawn has one pair of antennae, one on either side, just below the antennules. They are sensory, excretory and balancing in function. Antennules are attached on either side, below the bases of eye stalks. They are tactile in function. Nematocysts are present in cnidoblasts that act as organs of offence and defence. Millipedes belong to class myriapoda.
They are called thousand leggers because of possession of numerous walking legs. Body is made up of small head and 40 trunk segments, each with two pairs of jointed legs. Animals belonging to phylum porifera are mostly marine and a few are freshwater.
131. In contrast to annelids the platyhelminthes show
(a) absence of body cavity
(b) bilateral symmetry
(c) radial symmetry
(d) presence of pseudocoel.
Answer and Explanation:
131. (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 symmertry.
132. What is common about Trypanosoma, Noctiluca, Monocystis and Giardia ?
(a) these are all parasities
(b) these are all unicellular protists
(c) they have flageila
(d) they produce spores
Answer and Explanation:
132. (b): Protista is the kingdom of unicellular eukaryotes. The protists include heterotrophs, autotrophs, and some organisms that can vary their nutritional mode depending upon environmental conditions. Protists occur in freshwater, saltwater, soil, and as symbionts within other organisms. Trypanosoma, Noctiluca, Monocystis and Giardia are all unicellular protists.
133. Which one of the following is a matching set of a phylum and its three examples?
(a) porifera – Spongilla, Eupleciella, Pennatula
(b) cnidaria – Bonellia, Physalia, Aurelia
(c) platyhelminthes – Planaria, Schistosoma, Enterobius
(d) mollusca – Loligo, Teredo, Octopus
Answer and Explanation:
133. (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), 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.
134. Metameric segmentation is the characteristic of
(a) mollusca and chordata
(b) platyhelminthes and arthropoda
(c) echinodermata and annelida
(d) annelida and arthropoda
Answer and Explanation:
134. (d): Refer answer 76.
135. Annual migration does not occur in the case of
(a) arctic tern
(b) salmon
(c) Siberian crane
(d) salamander
Answer and Explanation:
135. (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 fresh water to spawn.
The Siberian crane, breeds in arctic Russia in Ykutia 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.
136. Which one of the following is not a living fossil?
(a) Peripatus
(b) king crab
(c) Sphenodon
(d) Archaeopteryx
Answer and Explanation:
136. (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 (the Platypus and echidnas), snout-nosed frog (Nasikabatrachus sahyadrensis).
Archaeopteryx 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 dinosour features. Archaeopteryx is a powerful piece of evidence that shows that birds have evolved from dinosaurs.
137. In which one of the following sets of animals do all the four give birth to young ones?
(a) kangaroo, hedgehog, dolphin, Loris
(b) lion, bat, whale, ostrich
(c) Platypus, penguin, bat, hippopotamus
(d) shrew, bat, cat, kiwi
Answer and Explanation:
137. (a): Kangaroo, hedgehog, dolphin and Loris are mammals and thus give brith to young ones. Ostrich and kiwi are birds 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.
138. Two common characters found in centipede, cockroach, and crab are
(a) book lungs and antennae
(b) compound eyes and anal cerci
(c) jointed legs and chitinous exoskeleton
(d) green gland and tracheae
Answer and Explanation:
138. (c): Centipede, cockroach, and crab all belong to phylum arthropoda which are characterized by jointed legs and chitinous exoskeleton. Arthropods have bilaterally symmetrical and metamerically segmented body with haemocoel and open blood vascular system.
139. Biradial symmetry and lack of cnidoblasts are the characteristics of
(a) Hydra and starfish
(b) starfish and sea anemone
(c) Ctenoplana and Beroe
(d) Aurelia and Paramecium
Answer and Explanation:
139. (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 (nematocystsl 1 found in coelenterates. but one species (Haeckelia rubra) incorporates those of its jellyfish prey for its own defense.
140. Earthworms are
(a) ammonotelic when plenty of water is available
(b) ureotelic when plenty of water is available
(c) uricotelic when plenty of water is available
(d) uricotelic under conditions of water scarcity
Answer and Explanation:
140. (a): Earthworm has excretory organ called nephridia. Ammonia is the chief excretory waste when water is available and hence it is ammonotelic in water and terrestrial earthworm is ureotelic.
141. What is true about Nereis, scorpion, cockroach and silver fish?
(a) they all possess dorsal heart
(b) none of them is aquatic
(c) they all belong to the same phylum
(d) they all have jointed paired appendages.
Answer and Explanation:
141. (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 rests of the animals belong to phylum arthropoda. Jointed appendages are present in scorpion, cockroach and silver fish.
142. What is common between parrot, platypus and kangaroo?
(a) toothless jaws
(b) functional post-anal tail
(c) ovoparity
(d) homoiothermy.
Answer and Explanation:
142. (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°C in mammals and 38-40°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.
143. Which one of the following is a matching pair of’ a body feature and the animal possessing it?
(a) Ventral central – Leech nervous system
(b) Pharyngeal gill slits – Chamaeleon absent in embryo
(c) Ventral heart – Scorpion
(d) Post-anal tail – Octopus.
Answer and Explanation:
143. (a): The animals mentioned in the options are invertebrates. These invertebrates have central nervous system and dorsal heart. They lack pharyngeal slits and post anal tail.
144. Which of the following pairs are correct matched?
Animals Morphological features
(i) Crocodile – 4-chambered heart
(ii) Sea urchin – Parapodia
(iii) Obelia – Metagenesis
(iv) Lemur – Thecodont
(a) (ii), (iii) and (iv)
(b) (b) only (i) and (iv)
(c) only (i) and (ii)
(d) (i), (iii) and (iv).
Answer and Explanation:
144. (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.
