Chordates (Short Questions and Answers)


Short Questions and Answers

One Mark Question with Answers

1. Long hollow bones with interconnected air passages are characteristic of

(a) reptiles

(b) aves

(c) mammals

(d) all land vertebrates

Answer: (b) aves

2. Which of the following is not clearly noticeable in birds?

(a) pectoral girdle

(b) pelvic girdle

(c) hind limb

(d) fore limb

Answer: (d) fore limb

3. Lizards deliberately break their tail to protect themselves from predators. The phemnomenon is called

(a) morphalaxis

(b) autotomy

(c) regeneration

(d) none of these

Answer: (b) autotomy

4. Which of the following is not a characteristic feature of all the chordates?

(a) dorsal nerve cord

(b) a diaphragm separating thorax from abdomen

(c) pharyngeal gill clefts in the early embryonic stages

(d) presence of coelom

Answer: (b) a diaphragm separating thorax from abdomen

5. One of the primary characters of chordates is

(a) solid ventral nerve cord

(b) dorsal tubular nerve cord

(c) paired nerve cord

(d) ganglionated nerve cord

Answer: (b) dorsal tubular nerve cord

6. The group of amniota includes

(a) reptiles and mammals

(b) birds and mammals

(c) reptiles, birds and mammals

(d) birds and reptiles

Answer: (c) reptiles, birds and mammals

7. In frog’s heart there are more muscular ridges which consists of fibres called

(a) purkinje fibres

(b) myonemes

(c) telodendria

(d) columnal carnae

Answer: (d) columnal carnae

8. RBCs are nucleated in

(a) man

(b) rabbit

(c) frog

(d) rat

Answer: (c) frog

9. Snake’s poisonous glands are modified

(a) oil gland

(b) lacrymal gland

(c) salivary gland

(d) thyroid gland

Answer: (c) salivary gland

10. In flying birds which of the following are useful in flight with addition pneumatic bone?

(a) syrinx

(b) quill feathers

(c) pygostyle

(d) furcula

Answer: (b) quill feathers

11. Which of the following exist in maximum number in terms of genera and species?

(a) herbivore mammals

(b) carnivore mammals

(c) aquatic mammals

(d) terrestrial mammals

Answer: (d) terrestrial mammals

12. Vestigial pelvic girdle and bones of hind limbs are characteristics of

(a) Whale

(b) Dolphin

(c) Seal

(d) Shark

Answer: (a) Whale

13. In which of the following fishes gill is covered by operculum?

(a) Torpedo

(b) Scoliodon

(c) Chimaera

(d) Trygon

Answer: (c) Chimaera

14. The bite of Cobra attacks which of the following systems of man?

(a) digestive

(b) circulatory

(c) respiratory

(d) nervous.

Answer: (d) nervous.

Two Marks Question with Answers

1. What is notochord?

Answer:  Notochord is a solid, unjointed stiff but flexible rod like structure situated on the mid dorsal side between the central nervous system and the alimentary canal. The notochord remains throughout the life in certain chordates, example, some protochordates. In vertebrates it is only found in the embryo, however in the adults, it is replaced by vertebral column (backbone).

2. Differentiate between chordates and non chordates.

Answer: A stiff and flexible rod of tissue, the notochord is present at some stage in the life of a chordate while notochord is not present at any stage in the life of a non chordate. Hollow central nervous system is present on the dorsal side of the body of a chordate while solid central nervous system lies on the ventral side of the body of non chordates. Gill slits are present in the pharynx either in the embryo or adult in chordates whereas gill slits are not present in non chordates. Heart is ventral in chordates whereas heart is dorsal in non chordates.

3. Differentiate between pisces and tetrapoda.

Answer: Fishes have paired appendages in the form of pectoral and pelvic fins while tetrapods have paired appendages in the form of five digited limbs. Pisces may possess an exoskeleton of dermal scales while tetrapods may possess exoskeleton of epidermal scales, feathers or hair. Fishes respire by means of gills whereas the tetrapods respire by the means of lungs. Heart is two chambered in pisces while heart is three or four chambered in tetrapods.

4. Mention some of the characteristic features of class mammalia.

Answer: These animals are warm blooded, hairy and have mammary or milk producing glands. They are the only animals which nourish their young ones with milk. Oil glands and sweat glands are present in the skin. The heart is four chambered. The skull is dicondylic. The kidneys are metanephric. A copulating organ is always present.

5. Differentiate between rabbit and hare.

Answer: Rabbit digs burrows and is thus fossorial in nature while hare makes small excavations under bushes or in grasses for shelter. Rabbit is gregarious while hare leads mostly a solitary life. Rabbit is crepuscular while hare is nocturnal. Rabbit can be domesticated while hare lives in wild stage. Hind limbs and pinnae are comparatively small in case of rabbit while the hand and limbs and pinnae are comparatively large in hare.

Three Marks Question with Answers

1. Differentiate between frog and toad.

Answer: Frog mostly lives in water but can come to land for feeding while toad lives on land and comes to water for breeding. Frog is diurnal while toad is not nocturnal. Frog lays eggs in a mass while toad lays eggs in line. The head is triangular in frog while the head is a semicircular in case of toad. The body of frog is olive brown with dark spots while the body of toad is brownish grey. The skin of frog is moist, smooth and acts as a respiratory organ. It has numerous mucous glands whereas the skin of a toad is rough dry and does not help in respiration. It has numerous poisonous glands and fewer mucous glands. Frog does not have parotid glands while toad has a pair of parotid glands.

2. Differentiate between Indian elephant and African elephant.

Answer: Pinnae are small and triangular in Indian elephant while the pinnae are large and rounded in African elephant. Forehead is high domed with a cleft in Indian elephant while forehead is low flat without a cleft in African elephant. Tusks are smaller in Indian elephant while the tusks are longer in African elephant. The Indian elephant has a rounded back while the African elephant has a concave back. The Indian elephant is found in Southern Asia and African elephants are found in Africa.

3. What features make a reptile successful on land?

Answer: Four features make reptiles true land animals.

(a) Internal fertilization

(b) The amnion encloses the embryo and provides it with a watery environment during development, therefore, the embryo does not need water environment.

(c) Shell around the egg to check desiccation.

(d) Horny scales on the body of reptiles check loss of water.

4. Mention some of the general characters of class aves.

Answer: Birds are bipedal feathered warm blooded animals. Their four limbs are modified into wings. The hind limbs are adapted for perching, walking or swimming, etc and usually bear four sometimes three and rarely two toes. Legs are modified for walking, hopping, grasping, perching, wading and swimming. The alimentary canal has additional chambers, the crop and gizzard. The crop stores and softens the food, however, the gizzard help in crushing and churning the food. There is cloacal aperture. The lungs are spongy and elastic. Air scas are connected with lungs. The heart is four chambered. The kidneys are metanephric. Birds have 12 pairs of cranial nerves. Sexual dimorphism is found in many birds. The fertilization is internal. All birds are oviparous.