Rajasthan Board RBSE Class 11 Biology Chapter 31 Classification of Vertebrates
RBSE Class 11 Biology Chapter 31 Multiple Choice Objective Questions
Question 1.
Operculum is absent in –
1. Dipnoi
2. Chondrichthyes
3. Osteichthyes
4. Holocephali
Question 2.
Which of the following group has marsupium-
1. Metatheria
2. Eutheria
3. Prototheria
4. Aves
Question 3.
Bag – like animal belong to which subphylum-
1. Cephalochordata
2. Urochordata
3. Vertebrata
4. Aves
Question 4.
Sea horse belongs to which class-
1. Mammalia
2. Pisces
3. Aves
4. Reptelia
Question 5.
Scales are found in –
1. Pisces
2. Reptiles
3. Aves
4. All the above
Question 6.
Rajasthan state bird is –
1. Gazella gazella
2. Great Indian bustard
3. Peacock
4. All the above
Answers :
(1). 2
(2). 1
(3). 2
(4). 2
(5). 4
(6). 2
RBSE Class 11 Biology Chapter 31 Very Short Answer Questions
Question 1.
Presence of “corpus callosum” is a feature of which mammals?
Answer :
Infraclass-Eutheria
Question 2.
What is the number of cranial nerves in the super class – Pisces?
Answer :
10 pairs
Question 3.
In which group, animal have distinct head and skull ?
Answer :
Craniata
Question 4.
The outermost covering of sub phylum urochordata is called as ?
Answer :
Tunica (Test)
Question 5.
Name any bioluminiscent animal ?
Answer :
Pyrosoma
Question 6.
Name the extincted animal of group agnatha.
Answer :
Ostracodermi
Question 7.
Which is the largest mammal ?
Answer :
Blue whale
Question 8.
In the fishes of which class, operculum is absent?
Answer :
Chondrichthyes
Question 9.
Tadpole larva is a feature of which class ?
Answer :
Amphibia
Question 10.
Which animals have 3-Chambered heart ?
Answer :
Class – Amphibia
Question 11.
Presence of diaphragm is a feature of which class?
Answer :
Class – Mammalia
Question 12.
Animals of which class have seven cervical vertebrae ?
Answer :
Class – Mammalia
Question 13.
Egg laying mammals belong to which group ?
Answer :
Prototheria
Question 14.
Name the National Animal of India.
Answer :
Panther a tigris (Tiger)
Question 15.
Write the Zoological name of lion.
Answer :
Panthera leo
RBSE Class 11 Biology Chapter 31 Short Answer Questions
Question 1.
Give four features of class mammalia.
Answer :
- Presence of corpus callosum in the brain.
- Presence of external, middle and internal ears.
- The external ear has distinct pinna. The middle ear consists of three ear ossicles.
- Presence of scrolled and porous turbinal bone in the nasal cavities.
- Presence of seven cervical vertebrae in the neck
Question 2.
What is the basis of division of chordates ?
Answer :
Following characters are used to classify the phylum Chordata –
- Skull – Presence of skull (Craniata) or absence of skull (Acraniata)
- Jaws – Absence of jaws (Agnatha) or presence of jaws (Gnathostomata)
- Locomotion – Locomotion by paired fins (Pisces) or locomotion by paired legs (Tetrapoda)
- Extra – embryonic membranes – Absent (Anamniota) or Present (Amniota)
Question 3.
Give five difference between chordata and non-chordata.
Answer :
| SN | Chordata | Non-Chordata |
| 1. | Presence of Notochord | Notochord is absent |
| 2. | Presence of mid dorsal and tubular nerve cord | Presence of mid ventral and solid nerve cord |
| 3. | Absence of gill slits in the pharynx | Presence of gill slits in the pharynx at one stage of life |
| 4. | Presence of hepatic portal system | Absent |
| 5. | Presence of ventral heart | Presence of dorsal heart |
| 6. | Hemoglobin is found in RBC |
RBC are absent and hemoglobin if present found in the plasma |
| 7. | Presence of post anal tail | Absent |
| 8. | They reproduce by sexual reproduction | Both asexual and sexual reproduction |
Question 4.
Write four salient features of flying animals.
Answer :
- Fore limbs modify to form wings
- Hind limbs are anterior placed and have 4 clawed digits.
- Absence of jaws and teeth
- Presence of beak made up of Keratin protein.
Question 5.
What do you mean by “amniotes”? Name the classes belong to this group.
Answer :
The animals having foetal membrances are called as amniotes. This group includes classes- Reptelia, Aves & Mammalia.
Question 6.
Define and give 2-2 examples of craniata and acraniata.
Answer :
The members of phylum Chordata without skull are called as Acraniata eg. Urochordata and cephalochordata. The animals having skull are called as craniata eg. Agnatha and Gnathostomata.
Question 7.
What do you mean by diphyodont ? Members of which class show this feature ?
Answer :
Appearance of two sets of teeth in the life is termed as diphyodont i.e. milk teeth and permanent teeth. It is a salient feature of class- mammalia.
Question 8.
Write four main features of Chondricthyes fishes.
Answer :
- Endoskeleton is cartilagenous
- Exoskeleton is of placoid scales
- Tail is heterocercal
- Absence of operculum
Question 9.
Which group of mammals has marsupium ? What is the importance of marsupium ?
Answer :
Members of Infraclass Metatheria bear a pouch like structure called marsupium. It is to keep young one till complete development.
Question 10.
Explain movement of fishes according to the season. Give examples.
Answer :
(a) Catadromous – Fresh water fishes which
migrate to sea for reproduction
Example : Anguilla.
(b) Anadromous – Marine fishes which migrate to fresh water for reproduction.
Example – Salmon, Hilsa, Trout etc
Question 11.
Name the class having dicondyllic skull.
Answer :
Following classes of phylum chordata bear dicondyllic skull viz. superclass-pisces, class- Amphibia, class-mammalia.
Question 12.
Write four features of infra class eutheria.
Answer :
- It includes true mammals.
- Presence of well developed pinnae.
- Presence of developed corpus callosum in the brain.
- Presene of developed mammary glands bearing distinct teats.
RBSE Class 11 Biology Chapter 31 Essay Type Questions
Question 1.
Write main features of class mammalia. Explain its sub classes with examples.
Answer :
Characters :
- They are cosmopolitan i.e found in all types of habitats.
- The skin is thick, water resistant and well developed. It consists of many types of glands and sense organs.
- Presence of corpus callosum in the brain.
- Presence of external, middle and internal ears. The external ear has distinct pinna. The middle ear consists of three ear ossicles.
- Presence of scrolled and porous turbinal bone in the nasal cavities.
- Presence of seven cervical vertebrae in the neck
- Presence of mammary glands which are normally functional in females. The mammary glands have teats or nipples.
- The teeth are thecodont, diphyodont and heterodont.
- Presence of diaphragm between thoracic and abdominal cavities.
- The thoracic cavity includes heart (inside the pericardial cavity) and lungs (inside the pleural cavity).
- Heart is perfectly four – chambered. RBC are enucleated and biconcave, sinus venosus in the heart is absent. Absence of right systemic arch and renal portal system.
- Presence of dicondyllic skull.
- The are homiothermic.
- They are ureotelic. kidneys are metanephric. Presence of well well developed urinary bladder,
- Presence of 12 pairs of cranial nerves.
- Presence of four optic lobes (corpora quadrigemina) in the brain.
- Presence of Graffian follicles in the ovary.
- Testes are exabdominal. In some, obdominal testes are found such as aquatic mammals (Whale, Dolphin, Seal etc.) & elephant.
- They are Oviparous or ovo-viviparous or viviparous.
- Presence of single copulatory organ and fertilization is internal.
- Eggs are alecithal or microlecithal or polylecithal.
- Formation of placenta in most of the mammals.
- They are amniotes.
- Absence of cloaca in most of the mammals.
Classification :
Class mammalia has been divided into two subclasses
(A) Subclass 1= Prototheria
Characters :
- They are reptile-like mammals.
- Mammary glands are without teats and are functional in both male & female.
- Absence of ear pinnae.
- Absence of corpus callosum in the brain.
- Presence of cloaca.
- Testes are abdominal.
- oviparous & ova are polylcithal.
Examples- Tachyglossus (Echidna or spiny anteater, inhabit Australia & Tasmania); Ornithorhyncus (Duck-billed platypus).
(B) Subclass 2 = Theria
It is furtner divided into two Infraclasses –
(a) Infraclass 1 = Metatheria Characters :
- Presence of ear pinnae.
- Presence of corpus callosum in the brain but less developed.
- In mammary glands only teats are distinct.
- The hind legs are much longer & stouter. They jump on the hind legs which is called as leaping.
- Presence of long & massive tail that maintains body balance during leaping.
- Presence of marsupial pouch or marsupium bearing teats in females.
- They are ovoviviparous i.e give birth to undeveloped young ones which are kept in the mursupium till complete development.
- Eggs are microlecithal.
- Absence of cloaca.
- Testes are exabdominal.
- Presence of yolk sac placenta.
Examples -Macropus (Kangroo), Didelphys (Oposum, found in South America), Bandicoot etc.’
(b) Infraclass-2 = Eutheria Characters :
- It includes true mammals.
- Presence of well developed pinnae.
- Presence of developed corpus callosum in the brain.
- Presence of developed mammary glands bearing distinct teats.
- Testes are exabdominal.
- Cloaca is absent.
- Eggs are alecithal and they are true viviparous,
- Placenta is allanto-chorionic type.
- It is further classified into 16 orders which are as follows –
- Order- Insectivora
Example – hedgehog, Shrew/mole etc. - Order- Dermoptera Example- Flying squirrel
- Order- chiroptera: It includes flying mammals, Fore limbs modify to form wings.
Exampls- Pteropus (Fruit bat), Rhinopoma (Insectivorus bat), Desmodus (vampire bat, blood feeder). - Order- Rodentia
Examples- Rat, Squirrel, Porcupine (Sehi, hair modify to form long spines), Guinea pig etc. - Order- Edentata
Examples- Bradypus, Colaepus, Trichecus Armadilo, Giant ant eater etc. - Order- Pholiclota
Example- Manis (Pongolin or scaly ant eater) - Order- Lagomorpha
Examples- Rabbit, Hare, Pika etc. - Order- Carniora
Examples- Panthera leo (lion), Panthera tigris (Tiger, National animal), Panthera pardus (leopard), Pelts domesticus (cat), Canisfamiliaris (dog), Canis lupus (Wolf), Canis aureus (Jackal), Ursus (Bear), Callorhinus (Sea lion), Pinnipedia (Seal), Odopenus (walrus) etc. - Order – Cetaceae
Example – Porpoise (smallest whale), Balaenoptera (Largest whale and Largest living mammal), Platanista gangetica gangetica (Ganga Dolphin, National aquation animal) etc. - Order – Siren
Example – Manatees (Sea cow), Dugong etc. - Order – Tubulidentata
Example – Aardwark - Order – Proboscida
Example – Elephas (Indian elephant), Loxodonta (African elephant) Largest living terrestrial animal) - Order – Hyracoidea
Example – Hyrax - Order – Artiodactyla (Even toed animals)
Example – Cow, Buffalo, camel, Gazella gazella (Chinkara, Rajasthan state animal), Goat. Sheep. Deer, Blue cow, yolk. Giraffe, Pig, Hippopotamus etc. - Order – Perissodactyla (odd toed animals)
Example – Horse, Donkey, Zebra, Rhinoceros (Gainda) etc - Order – Primata
Example – Homo sapiens sapiens (Man), Gorilla (Largest primata), Chimpanjee, Orang uttan, Gibbon, Monkey, Tapir. Baboon, Loris (Smallest primata) etc.
Economic Importance of class Mammalia :
Mammals are highly useful to human beings directly or indirectly.
(A) Useful Mammals –
Mammals play a vital role for the ecosystem in which they live. Various uses of Mammals are as follows –
(i) In Agriculture –
Many Mammals particularity Camel, OX etc are used in plowing the field. The excreta (Gobar and urine) of cattle’s is used as fertilizer as it is the good source of nitrogen and other nutrients. Gobar is used in Gobar gas plant in making gobar gas which is a good alternate source of energy used in Kitchen. The slurry left in the gobar gas plant is used as fertilizer.
(ii) In transportation –
Since long back mammals are used for transportation such as Camel. Elephant, Horse, Ox etc. Camels are very useful in desert. In Tundra region, tundra dogs and rain deer and in Tibet, Yalk are used for transportation.
(iii) Hunting and recreation –
Since ancient time man is hunting mammals for recreational purposes and to get food and other products. Hunting mammals such as Lagomorphs (Rabbit, Hare) and Ungulates (hoofed animals) has grown into a multi-billion dollar enterprise.
(iv) Medicines –
Many animal products have medicinal values. For example, milk of Cows and Goat is given to patients to drink being easily digestible. The liver oil of whale is a rich source of vit. A, hence useful for eyes. Many mammalian organs are consumed as food because of their medicinal values such as liver, adrenal, testes, thyroid, pituitary, thalamus etc.
(v) Oil –
Oil obtained from many mammals such as whale etc is used in making many products such as Soap,-Paint, Candles, Ointment, Shoe polish, Lubricants etc.
(vi) Products like Musk and Ivory –
Musk is a powerfiill aphrodisiac and used in making scent and musk have anti-inflammatory and anti- histaminic properties. The musk is obtained from Musk deer.
Ivory is a hard and white material obtained from elephant tusks and tusks of other mammals. The ivory is very costly and it is used to make many items like cutlery handles, musical instruments, billiard ball, piano keys, bangles etc.
(vii) Business point of view, the skin of many mammals is used as leather to manufacture purses, shoes, sandals, chap pals, suitcases etc. The hooves and horns are used to make toys, combs, frames, handles of knife, buttons etc. The hair of camel, horse and pigs are used to make brushes to polish shoes and for other purposes.
(viii) Skeleton –
The bones of dead mammals are used to make bone charcoal which is used in sugar industry. Bones of whales are used to get gum and gelatin which are used in making photographic films. The phosphate obtained from the bones is used to manufacture fertilizer like super phosphate etc.
(ix) For the amusement of public and foreign tourists many mammals such as monkeys, bear, rabbit, fox, lion, tiger, deer, blue cow, peacock etc are kept in the amusement parks and zoos.
(x) Many mammals such as rats, rabbit, guinea pig, squirrel are used in the laboratories to teach the students and for research purpose.
(xi) Many mammals feed on decaying organic matter and dead animals and clean the environment. They are called as scavengers.
Examples – Dogs, Pig, Jackal etc
(B) Harmful Mammals-
(i) Many wild and domestic mammals destroy the crop, seeds and saplings. Rats (Rattus rattus) primarily feed on grains, fruits, vegetables etc. In India the rat is the most destroyer of human food. Squirrel (Fun ambuluspennantii) destroy fruits, vegetables, flowers, peas etc. Wild boar (Sus scrofa) eat and destroy groundnut, sugar beat, potato, sugarcane, maize etc.
Blue cow (Boselaphus tragocamelus) eat and mine many types of crops particularly during morning and evening.
(ii) Some Mammals act as Vector for the human pathogens. Such as eating of less cooked meat of pig (pork) and meat of cow (Beef) cause infection of Taenia solium and Taenia sagginata respectively. Rabid Dogs, fox, monkeys etc transmit rabies disease. Rats transmit plague via fleas.
(iii) Many carnivorous wild mammals such as Lion, Tiger, Wolf etc hunt the useful domestic animals like goat, sheep, pig, hen, cow etc. Sometime, they also attack on human beings.
Question 2.
Give an account of reptilian characters and examples ?
Answer :
Characters :
- Mostly terrestrial but some are aquatic, mostly crawling but some are burrowing.
- Body is divisible into head, neck, trunk and tail.
- skin is rough, dry and without glands. The exoskeleton is of ecotodermal scales / scutes.
- Endoskeleton is bony and skull is mono / dicondyllic.
- Heart is incompletely four chambered i.e two auricles and two ventricles but ventricles are incompletely divided.
- RBC are oval, nucleated and biconvex.
- Presence of 12 pairs of cranial nerves.
- Renal portal system is present.
- They are uricotelic. Presence of a pair of metanephric kidneys.
- Urinary bladder is highly reduced.
- Sinus venosus is absent in the heart.
- Presence of three pairs of aortic arches.
- Respiration by a pair of lungs.
- They are Poikilothermic.
- Presence of middle and internal ears. The middle ear has columella auris.
- Uni sexual, internal fertilization, presence of one or two copulatory organs, direct development.
- Eggs are polylecithal, oviparous and eggs have leathery shell.
- They are amniotes i.e presence of four foetal membranes viz – amnion, chorion, allantois and yolk sac.
- Study of reptiles is called as herpetology.
Classification :
On the basis of temporal vacuities in the skull, it is divided into 4 sub classes viz
- Subclass – Anapsida –
• Absence of temporal vacuties in the skull.
• It is further divided into two orders –
(i) Order 1 – Cotylosauria
Example : Semouria – It is a connecting link between amphibia and reptelia.
(ii) Order 2 – Chelonia
Example : Trionyx (Fresh water terrapin); Chelone (Marine turtle); testndo (Terrestrial tortoise) - Subclass – Parapsida
• One pair of temporal vacuties in the skull.
• All are extinct
• Example : Dinosaurs - Subclass : Diapsida
• Presence of two pairs of temporal vacuities in the skull.
• It is divided into three orders-
(i) Order 1 – Rhyncocephalia
Example – Sphenodon (Tautara; living fossil)
(ii) Order 2 – Squamata
Examples – (A) Lizards = Hemidactylus (House lizard), Dracco (Flying lizard), Heloderma (Gilamoster, only poisnous lizard), Calotese (Girgit), Ophiosaurus (Limbless lizard or glass snake), Chameleon (Garden lizard) etc
(B) Snakes – Naja (Cobra), Hydrophis (Sea snake), Typhlops (Blind snake), Viper etc.
(iii) Order 3 – Crocdelia
Example – Crocodile, Gavialis, Alligator - Subclass – Synapsida
• Two pairs of temporal vacuties in the skull but two vacutie of one side fuse to become one. Completely extinct.
Example : Dimetrodon.
Economic Importance of class Reptilian :
(A) Useful Reptiles :
- Snakes feed on the animals that harm the crop such as rats, squirrel, locusts etc.
- Snake poison is used to synthesize drugs. Poison of Russel viper is used in haemophilia, this poison forms blood clot. Cobra poison is used in nervous disorders and to make homeopathy drug for heart diseases. Poison of Rattle snake is used to make homeopathy medicine for epilepsy, nervous fatigue, asthma etc.
- Reptilian specimens are kept in the laboratories of schools, colleges and in zoo to give knowledge to the students.
(B) Harmful Reptiles :
Snake poisons are lethal. The Poison of cobra, king cobra, black Mamba, krait, coral snake etc is Neurotoxic. The poison of viper, rattle snake etc is haemotoxic.
Question 3.
Write the main features of class amphibia.
Answer :
Characters :
- They are amphibious in nature i.e inhabit both water and land.
- Solitory, free living, free swimming and poikilothermic.
- Body is divisible into head, trunk and tail. The tail may be absent.
- Absence of exoskeleton
- Skin is soft slimy.
- Respiration by gills, skin and lungs.
- The skull is dicondyllic.
- RBC are nucleated and biconvex.
- The heart is 3 – Chambered (2 auricles and 1 ventricle)
- They exhibit hibernation and aestivation
- Presence of middle and internal ear. The middle ear has Columella auris structure.
- They are ureotelic. Kidneys are mesonephric.
- Presence of sinus venosus in the heart.
- Presence of 3 pairs of aortic arches viz – Carotid arches – 1 pair, Systemic arches – 1 pair and Pulmonary arches – 1 pair.
- External fertilization and indirect development.
- Oviparous and eggs are mesolecithal
- The larva is tadpole. Some have axolotle larva.
Question 4.
Write the features and examples of super class pisces.
Answer :
Salient features :
- Aquatic (both marine and fresh water), solitary free swimming, free living or ectoparasite or commensal.
- The body is streamlined (Boat shaped) and divisible into head, trunk and tail.
- Presence of Paired fins (Pectoral fins and Pelvic fins) and Unpaired fins (Caudal fins, dorsol fin, ventral fin). The fins are supported by fin rays (endoskeleton)
- Body is covered by mesodermal scales. They are placoid / ctenoid / cycloid / rhomboid type.
- They are poikilothermic.
- Presence of 5 to 7 pairs of gill slits. Some have Operculum or gill cover.
- Respiration is by gills
- Closed blood vascular system and RBC’s are nucleated and biconvex
- Presence of renal portal system.
- The heart is two – chambered (one auricle and one ventricle) and it is called as venous heart, as it contains only de oxygenated blood.
- Presence of sinus venosus in the heart.
- Presence of six pairs of aortic arches.
- Mostly ammonotelic but some excrete urea and TMAO (trimethyl amine oxide).
- Kidney are mesonephric and urinary bladder is absent.
- Presence of only internal ear bearing three semicircular canals
- Presence of ten pairs of cranial nerves.
- Uni sexual, fertilization is external or internal, direct development.
- Mostly Oviparous, Eggs are polylecithal
- Holoblastic and unequal cleavage.
- They are anamniotes i.e without foetal membranes.
- Some fishes exhibit seasonal migration which is of two types –
(a) Catadromous – Fresh water fishes which migrate to sea for reproduction”
Example : Anguilla.
(b) Anadromous – Marine fishes which migrate to fresh water for reproduction.
Example – Salmon, Hilsa, Trout etc - Skull is dicondyllic.