Comparative Anatomy 2019
1.a) What is deltoid ridge?
Ans→ Deltoid ridge is the triangular shaped region in the humerus of vertebrates that helps to join the muscle.
b) What is a branchiostegal membrane?
Ans→ The membrane connecting the branchiostegal and enclosing the gill chamber ventrally below the operculum present in fish is called branchiostegal membrane.
c) Which bones are transformed into Malleus and Incus in mammals?
Ans→ Meckel’s cartilage transformed into Malleus and Hyomandibular transformed into Stapes in mammals.
d) Name two receptors present within the skin?
Ans→ Meissner’s corpuscle and Pacinian corpuscle are two receptors present in skin.
e) What is diastema?
Ans→ Any gap within the dental series of an organism is called diastema.
f) Actually what the operculum in fish is ?
Ans→ Operculum is the bony flap that serves as a facial support structure and a protective covering for the gills and allows water to pass over the gills found in bony fishes.
g) Why is Bulbus not a part of the heart?
Ans→ The bulbus, found in fish, serves as a muscular pump that helps regulate blood pressure and flow. It’s not considered part of the heart because it functions differently from the chambers of the heart, which primarily pump blood.
h) Write the name of a toothless Mammalian species.
Ans→ Echidna, Spiny ant-eater, Megaptera (Hump) back whale is a toothless mammalian species.
i) Write the name of the first and second visceral arch in Vertebrates.
Ans→ First visceral arch is Mandibular arch and Second visceral arch is Hyoid arch.
j) Name the Amphibian species where gill is retained throughout life?
Ans→ Axolotl (Ambystoma mexicanum).
k) What is dicondylar skull ? Give one example.
Ans→ When two occipital condyles are present in the skull then it is called dicondylar skull.
Example: Amphibians, Mammals (Human)
l) From which part of the body does the lung develop?
Ans→ Single mid ventral diverticulum from the floor of pharynx.
m) Which tooth is modified as Tusk in Elephant?
Ans→ Second pair of incisors is modified as Tusk in Elephant.
n) Write the names of the auditory ossicles?
Ans→ Malleus, Incus and stapes are the names of the auditory ossicles.
o) What is lanugo?
Ans→ Lanugo are fine, downy hair on the foetus body, typically shed within the first week after the birth.
2.a) What is Ductus Caroticus? State its significance?
Ans→ Ductus Caroticus: The vascular connection between the III and IV aortic arches or lateral dorsal aortae is called ductus caroticus.
Significance: Ductus Caroticus supplies oxygenated blood to the vital areas like the head and neck.
b) What do you mean by opisthonephric kidney?
Ans→ Opisthonephric kidney is the adult kidney of shark and mudpuppy, developed from the posterior part of the nephric tubule.
Formed from the extended mesonephros along with tubules form the posterior nephrice ridges.
c) Why are receptors called biological transducers?
Ans→ Receptors are the specialized structures that convert any type of electrical energy into or action potential in afferent fibres resulting in transduction. Hence, receptors called biological transducers.
d) What is Mullerian duct?
Ans→ Mullerian duct is the embryonic structure that develops into the female reproductive tract after that it is modified into oviduct and uterus etc.
e) What is a bipartite uterus?
Ans→ When two uteri are seperate for most of their length and fuse at lower end but share a single cervix then it is known as bipartite uterus.
Example:Cattles, carnivores, rodents etc.
f) What is whisker? Why it is called as ‘feeler’?
Ans→ Long hairs that grows near the mouth of some animals such as mouse, cat, etc. are called whisker. Helps to sense their surroundings by sending signals to the brain that’s why they are called feeler.
g) Write the difference between horn and antler?
Ans→
h) Write the difference between lung and swim bladder?
Ans→
Comparative Anatomy 2021
1.a) Explain dicondylar skull?
Ans→ When two occipital condyles are present in the skull then it is called dicondylar skull.
Example: Amphibian, mammals have dicondylar skull.
b) What is preen gland ?
Ans→ A branched gland located on the dorsal side of the base of the tail secrete oil through a common duct is called preen gland.
c) What is foramen triosseum ?
Ans→ Foramen triosseum is an opening enclosed by the clavicle, scapula and coracoid bone of a bird at the point where these three bones meet.
d) What is ductus Cuvieri?
Ans→ A pair of blood vessels that conduct/carry blood, ventrally from the cardinal vein to the sinus venosus of heart of the vertebrate embryo is called ductus Cuvieri.
e) What is ruminant stomach?
Ans→ Ruminant stomach has more than one compartment of stomach and allows food and then brings it back up again to chewing.
f) What is bunodont tooth?
Ans→ When the cusps of the cheek tooth are round and remain separate from each other then it is called bunodont tooth.
Example: Bears
g) Lizard has which type of kidney?
Ans→ Lizard has metanephric type of kidney.
h) What is ductus arteriosus?
Ans→ The ductus arteriosus is a blood vessel in foetal circulation that connects the pulmonary artery to the aorta, allowing blood to bypass the lungs.
i) What is Pronghorn ?
Ans→ A type of horn formed by the central bony core that bears 1-3 branches which is shedded off every year is called Pronghorn.
j) What is crura cerebri ?
Ans→The crura cerebri, or cerebral peduncles, are bundles of nerve fibres that connect the cerebrum to the brainstem.
They play a crucial role in transmitting signals between different parts of the brain.
k) What is corpus striatum?
Ans→ The floor of the cerebral hemisphere is differentiated by a reticulated structure called corpus striatum.
l) Name the 11th cranial nerve of mammals.
Ans→ Accessory Nerve is the 11th cranial nerve of mammals.
m) What is amphicoelous vertebrae?
Ans→ When the vertebrae is biconcave in the centre of both anterior and posterior part of the vertebrae then it is called amphicoelous vertebrae.
n) What is the Aqueduct of Sylvius?
Ans→ III ventricle connected by IV ventricle by a narrow canal in the brainstem of the brain is called the aqueduct of sylvius.
o) What is foramen magnum?
Ans→ Foramen magnum is a large, oval-shaped opening in the occipital bone of the skull where the spinal cord passes through it.
2.a) Write the difference between claw and nail.
Ans→
b) What are scutes and states it’s function.
Ans→ Scutes are thickened, large horny or bony plates found on the shells of reptiles, particularly turtles and crocodiles.
Function: They provide armor-like protection against predators and environmental hazards.
c) Cite examples where you can observe acrodont and homodont type of dentition.
Ans→ Acrodont: Fishes, Amphibians, some reptiles.
Homodont: Fishes, Amphibians, Reptiles and toothed whales.
d) What is the difference between physostomous and physoclistous type of swim bladder.
Ans→
e) Difference between Foramen of ovale and foramen of Panizza.
Ans→
f) What is the difference between beak and bill.
Ans→
g) What is the function of Jacobson organ and where is it found?
Ans→ The Jacobson’s organ, found in reptiles like snakes, detects pheromones, helping in identifying prey, predators, and potential mates.
Comparative Anatomy 2022
1.a) What is autostylic jaw suspension?
Ans→ Autostylic jaw suspension is a primitive jaw structure found in some fish where the palatoquadrate (upper jaw) is directly attached to the skull, without a separate hyomandibula bone.
b) Name the animal where we found the baleen.
Ans→ Baleen whales have baleen instead of teeth which they use to collect shrimp like krill, plankton & small fishes.
c) State the function of Rete mirabile.
Ans→ Regulates to body temperature by either conserving or dissipating heat, depending on the environmental conditions.
Rete mirabile is a network of blood vessels that acts as a heat exchanger.
d) What is claw?
Ans→ Claw is an epidermal derivative which is a hard, pointed, narrow, curved horny plate at the tips of the toes of birds and most mammals.
e) What is holonephros kidney?
Ans→ The holonephros kidney is a simple, primitive type of kidney found in some aquatic vertebrates, consisting of a single, undivided tubule.
f) What is foramen of ovale?
Ans→ The foramen of ovale is an opening in the heart between the allowing blood to flow from the right atrium to the left atrium during foetal development.
g) What is the function of uropygial gland?
Ans→ Function of uropygial gland are:-
- i) It helps in waterproofing the feathers.
- (ii) Attract opposite sex through its odour.
- (iii) Secrete lubricants that keep their feathers from drying completely.
h) Write the function Weberian ossicles.
Ans→ Helps to intensify sound vibrations and convey the waves to the internal ear.
i) What is opisthocoelous vertebrae?
Ans→ A vertebrae which have a concave structure in its anterior side and a depressed & structure in the posterior side is called opisthocoelous vertebrae.
j) Give the definition of rumination. Ans→ Ruminiation is the process where animals rechew cud to breakdown plant matters further to stimulate digestion.
k) Give two examples where we found tusk.
Ans→ Elephant, wild boar, musk deer, walrus.
l) What is Reissner’s membrane?
Ans→ Ressiner’s membrane is a thin membrane found in the inner ear of some vertebrates, serving to separate the scala vestibuli from the scala media.
m) Write the function of proventriculus and gizzard.
Ans→ Proventriculus : Functions as the glandular stomach in birds, secretes digestive enzymes to break down food before it enters the true stomach.
Gizzard: Acts as a muscular grinding organ in birds, helps in mechanical digestion by grinding food particles.
n) Write the difference between horn and antler.
Ans→
o) Write the difference between sweat gland and of sebaceous gland.
Ans→
2.a) Draw a labelled diagram of a typical teleost fish heart.
Ans→
b) What is foramen of Panizza? What is the significance of presence.
Ans→ A hole/opening present between the right and left systemic aorta of the heart of crocodiles is called foramen of Panizza.
Significance:The foramen of Panizza is significant in crocodiles as it allows blood to bypass the pulmonary circulation, aiding in maintaining blood pressure while diving or holding breath underwater.
c) Write the difference between countercurrent and crosscurrent gas exchange.
Ans→
d) Differentiate between carapace and plastron. Where they are found.
Ans→
Carapace and plastron are found in shell of tortoises or turtles.
e) Write the distributions of glossopharyngeal nerves and olfactory nerves.
Ans→ Olfactory nerve (CN I) is responsible for smell and is distributed within the nasal cavity.
Glossopharyngeal nerve (CN IX) serves taste and other sensation in the throat and is distributed in the back of the throat and tongue.
f) What are the different types of scales found in fish.
Ans→ Fish have various types of scales. Most important types of scales are – (1) Placoid scale (2) Cycloid scale (3) Ctenoid scale (4) Ganoid scale (5) Cosmoid scale.
g) Write down the difference between gills of chondrichthyes and osteichthyes fish.
Ans–>
h) What are scent glands? write the function of scent glands.
Ans→ Scent glands are specialized glands found in animals that produce and release odorous substances for various purposes such as communication, marking territories, attracting mates etc.
Comparative Anatomy 2023
1. a) What is foramen triosseum?
Ans→ Foramen triosseum is an opening enclosed by the clavicle, scapula and coracoid bone of a bird at the point where these three bones meet.
b) What is craniostylic jaw suspension?
Ans→ Craniostylic jaw suspension is a type of jaw attachment in vertebrates where the upper jaw is fused with the skull and the lower jaw is directly attached to the cranium.
Example: This suspension seen is Mammals.
c) Define lophodont teeth.
Ans→ When the cusps of teeth are joined to form ridges or lophs, then teeth are called lophodont teeth.
d) Distinguish between remiges and rectrices.
Ans→
| Points | Remiges | Rectrices |
| 1. Location | These are the primary flight feathers located on the wings of a bird. | These are the tail feathers of a bird. |
| 2. Function | They provide lift and thrust during flight. | They provide stability and control during flight. |
e) What is bulbus arteriosus?
Ans→ The bulbus arteriosus is a flexible, muscular structure in the hearts of fish that helps to regulate blood flow from the heart to gills.
f) Write one function of each of sebaceous and sweat glands.
Ans→ Sebaceous gland: Produce sebum which lubricates and waterproofs the skin and hair.
Sweat gland: Produces sweat, which helps to regulate body temperature.
g) What is harderian gland?
Ans→ Harderian gland is a gland found in the eyes of some vertebrates, produce secretions that lubricate the eye. It plays a role in immune response and pheromone production to some species.
h) Where you can found the archinephros type of kidney?
Ans→ In cyclostomes
i) What is amphicoelous vertebrae?
Ans→ When the vertebrae is biconcave in the centre of both anterior and posterior part of the vertebrae then it is called amphicoelous vertebrae.
j) State the number of aortic arches present in crocodile and man.
Ans→ Crocodiles have 2 pairs of aortic arches in adulthood.
And man has 1 pair of aortic arches in adulthood that form the main arch of aorta.
k) Write the distribution of vagus nerve.
Ans→ The Vagus nerve (X) is distributed to the throat, organs of the trunk like heart, lungs and stomach and the roof of the tongue.
l) What is Meissner’s corpuscle?
Ans→ Meissner’s corpuscle is a sensory receptor in the skin responsible for detecting light, touch and texture.
m) Mention the type of skull found in snakes.
Ans→ Monocondylic skull found in snakes.
n) Why single heart is called venous heart.
Ans→ A single circuit heart is called a venous heart because it pumps blood primarily through the venous system, where blood returns from the body to the heart without passing through a separate pulmonary circuit.
o) What do you mean by honeycomb chamber?
Ans→ The honeycomb chamber in a ruminant’s stomach refers to the reticulum, which has a distinctive honeycomb-like inner structure that traps and sorts feed particles, facilitating regurgitation and rechewing (rumination).
2. a) How cellulose is digested in a ruminant stomach?
Ans→ Ruminants swollen partly chewed food into rumen where the food is churned, mixed with certain bacteria. Cellulase is produced from
b) Write the evolutionary significance of hyomandibular bone.
Ans→ The hyomandibular bone in early vertebrates evolved into the stapes in tetrapods, an essential bone is the middle ear that helps in hearing. This transformation illustrates a significant evolutionary adaptation from Jaw function in aquatic animals to sound transmission in terrestrial animals.
c) Write two peculiar characteristics of dipnoi heart.
Ans → They have dual respiratory systems both gills and lungs allowing them to breathe in water and air.
d) Write a short note on respiratory organs found in Amphibia.
Ans→ Skin (Cutaneous Respiration): Many amphibians can breathe through their skin, which must remain most to allow efficient gas exchange.
Gills: Larval amphibians have gills for underwater respiration.
Lungs: Most adult amphibians have simple, sac-like lungs for breathing air.
e) What is the difference between connective and commissure?
Ans→
| Points | Connective | Commissure |
| 1. Definition | Refers to any structure that connects two parts within an organism in the nervous system. | refers to a bundle of nerve fibres that cross the midline of the brain or spinal cord |
| 2. Location | Found throughout the body, such as the nervous, muscular, and skeletal systems. | Found in the central nervous system. |
| 3. Example | Nerve tracts like the spinal nerves connecting the spinal cord to the rest of the body. | Corpus callosum in the brain, anterior commissure, posterior commissure. |
| 4. Orientation | Can connect structures in various orientations and planes. | Oriented to cross the midline, connecting left and right symmetrical parts. |
f) Differentiate between the structure of conus arteriosus of an Elasmobranchs and a Teleosts.
Ans→
| Points | Conus Arteriosus of an Elasmobranchs | Conus arteriosus of an Teleosts(Bulbus Arteriosus) |
| 1. Number of valves | Has multiple rows of valves (usually 3-5 rows) | Has a single row of valves at its base. |
| 2. Musculature | The conus arteriosus is muscular. | Largely non-muscular. |
| 3. Function | Active role in pumping blood and regulating pressure. | Serves to smooth out the pulsatile nature of the blood flow from the heart to the gills. |
| 4. Evolutionary adaptation | Reflects for their more primitive circulatory system. | Conus arteriosus modified into the bulbus arteriosus. |
g) What is the difference between Wolffian duct and Mullerian duct?
Ans→
| Points | Wolffian Duct | Mullerian Duct |
| 1. Embryological origin | Develops from the mesonephros. | Develops from the intermediate mesoderm. |
| 2. Development | Develops into male reproductive structures (epididymis, vas deferens, seminal vesicles) | Develops into female reproductive structures (fallopian tubes, uterus) |
| 3. Fate | Regresses in the absence of testosterone. | Regresses under the influence of Anti-Müllerian Hormone (AMH). |
| 4. Hormonal influence | Requires testosterone and Anti-Müllerian Hormone (AMH) for development in males. | Regresses in males due to the action of AMH produced by Sertoli cells. |
h) What are scala vestibuli and scala tympani?
Ans→
Scala Vestibuli: A fluid-filled chamber in the cochlea of the inner ear, located above the cochlear duct and filled with perilymph, transmitting sound vibrations from the oval window to the cochlear duct.
Scala Tympani: A fluid-filled chamber in the cochlea of the inner ear, located below the cochlear duct and filled with perilymph, transmitting sound vibrations from the cochlear duct to the round window.
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