Question
Which among these is the correct combination of aquatic mammals? [NEET 2017]
(a)Seals, Dolphins, Sharks
(b) Dolphins, Seals, Trygon
(c) Whales, Dolphins, Seals
(d) Trygon, Whales, Seals
Answer/Explanation
Ans. (c)
Among the given options, option(c) contains all aquatic mammals. Whales are inhabitants of the open sea, while seal (Phoca) is a marine carnivore.
Dolphins are found in rivers. Trygon and sharks are fishes, which belong to chondrichthyes class of superclass-Pisces.
Question
Which one of the following characteristics is not shared by birds and mammals? [NEET 2016, Phase I]
(a) Breathing using lungs
(b) Viviparity
(c) Warm blooded nature
(d) Ossified endoskeleton
Answer/Explanation
Ans. (b)
Mammals are viviparous while birds are oviparous. Viviparous means giving birth to offspring that develops within the mother’s body. Oviparous means producing eggs that hatch outside the body of mother.
Question
Compared to those of humans, the erythrocytes in frog are [CBSE AIPMT 2012]
(a) without nucleus but with haemoglobin
(b) nucleated and with haemoglobin
(c) very much smaller and fewer
(d) nucleated and without haemoglobin
Answer/Explanation
Ans. (b)
RBCs or erythrocytes of frog are oval, disc-like biconvex, have centrally placed nucleus and with haemoglobin. Usually in mammals (including human). RBCs are circular and non-nucleated except those of family-Camilladae (camels, llamas, etc), which have nucleated RBCs.
Question
What is common between parrot, platypus and kangaroo? [CBSE AIPMT 2007]
(a) Homeothermy
(b) Toothless jaws
(c) Functional post-anal tail
(d) Oviparity
Answer/Explanation
Ans. (a)
Parrot (birds), platypus and kangaroo (both mammal) are homeothermic animals.
Question
In which one of the following sets of animals do all the four give birth to young ones? [CBSE AIPMT 2006]
(a) Lion, bat, whale, ostrich
(b) Platypus, penguin, bat, hippopotamus
(c) Shrew, bat, cat, kiwi
(d) Kangaroo, hedgehog, dolphin, loris
Answer/Explanation
Ans. (d)
Kangaroo, hedgehog, dolphin and loris are all mammals. These give birth to young ones.
Question
153 Which one of the following characters is not typical of the class-Mammalia? [CBSE AIPMT 2005]
(a) Seven cervical vertebrae
(b) Thecodont dentition
(c) Ten pairs of cranial nerves
(d) Alveolar lungs
Answer/Explanation
Ans. (c)
Ten pairs of cranial nerves are not common in mammals but common in frog. In mammals 12 pairs of cranial nerves are found.
Question
A terrestrial animal must be able to [CBSE AIPMT 2004]
(a) excrete large amounts of water in urine
(b) conserve water
(c) actively pump salts out through the skin
(d) excrete large amounts of salts in urine
Answer/Explanation
Ans. (b)
Since, terrestrial animals do not have automatic access to either fresh or salt water, they must regulate water content in other ways, balancing off gains and losses.
Question
Given below are four matchings of an animal and its kind of respiratory organ [CBSE AIPMT 2003]
(i) silver fish – trachea
(ii) scorpion – booklung
(iii) sea squirt – pharyngeal gills
(iv) dolphin – skin
The correct matchings are
(a)(ii) and (iv)
(b)(iii) and (iv)
(c)(i) and (iv)
(d)(i), (ii) and (iii)
Answer/Explanation
Ans. (d)
Dolphins are mammals which respire by lungs, which are situated next to the heart in the thorax cavity.
Question
Trachea of cockroach and mammal are similar in having [CBSE AIPMT 1993]
(a) paired nature
(b) non-collapsible walls
(c) ciliated inner lining
(d) origin from head
Answer/Explanation
Ans. (b)
The trachea of cockroach and mammals is lined with spiral thickening of cuticle called intina which prevents the tracheal tubes from collapsing.
Question
What is common in whale, bat and rat? [CBSE AIPMT 1993, 2000, 04]
(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/Explanation
Ans. (b)
The presence of diaphragm is a characteristic feature of mammals, diaphragm acts as a separater between thorax and abdomen. Whale, bat and rat all are mammals and have diaphragm.
Question
Gorilla, chimpanzee, monkeys and human belong to the same [CBSE AIPMT 1993]
(a) species
(b) genus
(c) family
(d) order
Answer/Explanation
Ans. (d)
Gorilla, chimpanzee, monkeys and humans these all belong to same order-Primata of class-Mammalia.
Question
The cervical vertebrae in humans is [CBSE AIPMT 1993]
(a) same as in whale
(b) more than that in rabbit
(c) double than that of horse
(d) less than that in giraffe
Answer/Explanation
Ans. (a)
The number of cervical vertebrae is constant, i.e. 7 in number in all mammals except sea cow and sloth. So, the cervical vertebrae in humans is same as in whale.
Question
An egg laying mammal is [CBSE AIPMT 1992, 2000]
(a) kangaroo
(b) platypus
(c) koala
(d) whale
Answer/Explanation
Ans. (b)
Egg laying mammals are primitive mammals classified under sub-class-Prototheria. These are oviparous, reptile-like mammals, confined to Australian region.
Ornithorhynchus, (duck billed platypus) is found is Australia and New Zealand is an egg laying mammal.
Question
Kidney of adult rabbit is [CBSE AIPMT 1991]
(a) pronephros
(b) metanephros
(c) mesonephros
(d) opisthonephros
Answer/Explanation
Ans. (b)
Kidney of adult rabbit is metanephros which is divided into cortex and medulla and its duct is useless. This is most advanced type of kidney found in man and rabbit.
Question
Eutherians are characterised by [CBSE AIPMT 1989]
(a) hairy skin
(b) true placentation
(c)ovoviviparity
(d)glandular skin
Answer/Explanation
Ans. (b)
Infraclass-Eutheria includes viviparous placental mammals. They give birth to young ones, which gets nourishment through placenta inside the body of its mother.
Question
Hair occur in all mammals except those of [CBSE AIPMT 1988]
(a) Rodentia
(b) Chiroptera
(c) Primata
(d) Cetacea
Answer/Explanation
Ans. (d)
Order-Cetacea of mammals consists of aquatic mammals in which hairs are present only on snout, e.g. porpoise, killer whale, dolphin, blue whale, sperm whale, etc.