Anatomy of Animals MCQ Quiz - Objective Question with Answer for Anatomy of Animals - Download Free PDF

The correct answer is The statement is false for water but true for land 

Concept:

• Frogs are amphibians, meaning they live both in water and on land. To adapt to these two distinct environments, frogs have evolved specialized respiratory mechanisms.
• Respiration refers to the process through which organisms exchange gases with their environment, primarily oxygen and carbon dioxide.
• Frogs use different organs for respiration depending on whether they are in water or on land. These organs include skin, buccal cavity (mouth cavity), and lungs.

Explanation:

• In water: Skin acts as aquatic respiratory organ (cutaneous respiration). Dissolved oxygen in the water is exchanged through the skin by diffusion.
• On land: The buccal cavity, skin and lungs act as the respiratory organs. The respiration by lungs is called pulmonary respiration. The lungs are a pair of elongated, pink coloured sac-like structures present in the upper part of the trunk region (thorax). Air enters through the nostrils into the buccal cavity and then to lungs.
• During aestivation and hibernation gaseous exchange takes place through skin.

The correct answer is Kidney and lower part of the body.

Explanation:

• Special venous connection between liver and intestine as well as the kidney and lower parts of the body are present in frogs. The former is called the hepatic portal system and the latter is called renal portal system.
• The circulatory system in frogs consists of a heart, blood vessels, and blood. It includes different types of blood vessels such as arteries, veins, and capillaries.
  • Hepatic Portal System: This system involves a network of veins that carry blood from the digestive organs and spleen to the liver. This allows the liver to process and detoxify substances absorbed from the digestive tract before they enter the general circulation.
  • Renal Portal System: This system consists of veins that carry blood from the lower part of the body, particularly the hind limbs, to the kidneys. This allows the kidneys to filter out waste products and excess substances from the blood before it returns to the heart.

The correct answer is First digit of fore limb.

Explanation:

• Frogs exhibit sexual dimorphism.
• Male frogs can be distinguished by the presence of sound producing vocal sacs and also a copulatory pad on the first digit of the fore limbs which are absent in female frogs.
• Female frogs do not have a specialized first digit on their forelimbs for this purpose; it is specifically a feature of male frogs.
• The copulatory pad in male frogs helps in securing the male to the female during the process of amplexus (mating)

The correct answer is Vena cava

Concept:

• Frogs have a three-chambered heart consisting of two atria and one ventricle. Their circulatory system is a double circulation system, meaning blood flows through the heart twice before completing a full circuit.
• Deoxygenated blood from the body is returned to the heart through the vena cava, which is the main vein responsible for transporting this blood.
• The vena cava carries deoxygenated blood from the various tissues and organs to the right atrium of the frog's heart.

Explanation:

• The vascular system of frog is well-developed closed type.
• Frogs have a lymphatic system also. The blood vascular system involves heart, blood vessels and blood.
• The lymphatic system consists of lymph, lymph channels and lymph nodes.
• The heart is a muscular structure situated in the upper part of the body cavity.
• It has three chambers, two atria and one ventricle and is covered by a membrane called pericardium.
• A triangular structure called sinus venosus joins the right atrium.
• It receives blood through the major veins called vena cava.

The correct answer is 3

Explanation:

• Frog has different types of sense organs, namely organs of touch (sensory papillae), taste (taste buds), smell (nasal epithelium), vision (eyes) and hearing (tympanum with internal ears).
  • Out of these, eyes and internal ears are well-organised structures and the rest are cellular aggregations around nerve endings.
  • Eyes in a frog are a pair of spherical structures situated in the orbit in skull. These are simple eyes (possessing only one unit).
  • External ear is absent in frogs and only tympanum can be seen externally.
  • The ear is an organ of hearing as well as balancing (equilibrium).
• The brain is divided into fore-brain, mid-brain and hind-brain. Forebrain includes olfactory lobes, paired cerebral hemispheres and unpaired diencephalon. The midbrain is characterised by a pair of optic lobes. Hind-brain consists of cerebellum and medulla oblongata.
• The vascular system of frog is well-developed closed type. Frogs have a lymphatic system also. The blood vascular system involves heart, blood vessels and blood. The lymphatic system consists of lymph, lymph channels and lymph nodes.

Concept:

• Thermoregulation is the mechanism by which some animals like mammals maintain their core body temperature irrespective of the changing environmental temperature.
• Based on whether an animal can maintain their body temperature or not they are divided into two: Homeotherm and Poikilotherms.

1. Homeotherm: An animal that can maintain constant internal body temperature. Birds and mammals are homeotherms.
2. Poikilotherm: An animal that cannot maintain a constant internal body temperature. The internal temperature in these animals varies generally with the varying environmental temperatures. Amphibians and reptiles are poikilotherms.

Explanation:

• Frogs are poikilotherms i.e. they cannot maintain a constant body temperature.
• Their body temperature fluctuates with that of the environment.
• During winters, the frog's body temperature becomes too low. As a result of which all the body activities of the frog get ceased and it becomes sluggish.
• Similarly during summers, due to high temperatures again the body's activities cease and the animal becomes sluggish.
• To avoid such harsh environmental conditions, frogs undergo special adaptations that enable them to survive in unfavorable conditions.
• Hibernation and Aestivation are the two adaptations taken up by the frog to avoid unfavorable conditions.

HIBERNATION:

• Hibernation is also known as winter sleep.
• During winters, frogs dig deep down into damp earth at the bottom of the ponds and rest there.
• During hibernation, lung breathing is stopped in the frog.
• The skin continues breathing which suffices the oxygen requirement of the frog during hibernation.

AESTIVATION:

• Aestivation is also known as summer sleep.
• Just like in hibernation, during aestivation too frogs burrow themselves into the damp earth.
• On the arrival of the rainy season, the animal resumes its normal body activities.

So from the above-given information, the correct answer is option 4 (Skin only).

Additional Information

•  Ectotherm: Ectotherms rely on the external environment to regulate their body temperature. These are also called cold-blooded animals. Poikilotherms are regarded as ectotherms.
• Endotherm: Endotherms are animals that maintain their own body temperature through metabolic activities. These are also called warm-blooded animals. Homeotherms are regarded as endotherms.

The correct answer is Xylem.

Key Points

• Complex Permanent Tissue: A cluster of structurally distinct cells carrying out a common function or series of functions is referred to as complex permanent tissue. They are composed of various cell types. 
• Phloem and xylem are examples of these tissues.  
  • Xylem:
    • It facilitates the movement of water and dissolved materials throughout the plant.
    • The various parts of the xylem consist of parenchyma, vessels, tracheids, and xylem fibers.
    • Lignin makes up the xylem fibers and cheids, which give the plant structural support.
  • Phloem:
    • Food particles can be transported with the help of phloem.
    • Complementary cells, sieve cells, sieve tubes, phloem fibers, and phloem parenchyma make up phloem.

Additional Information

• Permanent tissues: Although these cells can no longer spread, they are specialized to provide the plant with strength, elasticity, and flexibility.
  • These tissues also fall into the following categories:
    • Simple Permanent Tissue
    • Complex Permanent Tissue​​
• Collenchyma: These are live, elongated cells with minuscule spaces between them.
  • Pectin and cellulose make up their cell walls.
  • It provides plants with mechanical support and a flexible structural framework.
  • It is found on the margins of leaves and stems.
• Plants have an apical meristem, an area of cells that can divide and expand at the terminals of their roots and shoots.
  • The apical meristems extend the roots and shoots and give rise to the main body of the plant.
  • Because this and other meristems can divide indefinitely, unlike most mammals, plants can grow for the entirety of their lives.
• Lateral meristems : This kind of meristem is found along the stem and root's longitudinal axis.
  • Another name for it is a secondary meristem.
  • Through division, the lateral meristem's cells proliferate and aid in the thickening of the stem and root.
  • One kind of lateral meristem that creates the xylem and phloem is the vascular cambium.

The correct answer is Involuntary muscles.

Key Points

• Skeletal muscle fibers are cylindrical, multinucleated, striated, and under voluntary control.
• Smooth muscle is an involuntary, non-striated muscle.
  • They are spindle-shaped, have a single, centrally located nucleus, and lack striations.
• As the name suggests, Cardiac muscles are the muscles of the heart.
  • Many cardiac muscle cells assemble in a branching pattern to form a
    cardiac muscle.
  • Based on appearance, cardiac muscles are striated.
  • They are involuntary in nature as the nervous system does not control their activities directly
• Visceral muscles are located in the inner walls of hollow visceral organs of the body like the alimentary canal, reproductive tract, etc.
  • They do not exhibit any striation and are smooth in appearance.
  • Hence, they are called smooth muscles (nonstriated muscle).

The correct answer is Neck.

• The neck is absent in Frog.

Key Points

• The frog's body is divided into the head, trunk, and limbs or legs.
• All frogs lack necks and tails.
• Frogs come under the phylum Amphibia.

​

Amphibia

• These are found both on land and water.
• All these are cold-blooded.
• Respiration takes place through the gill, skin, and lungs.
• They have three-chambered hearts.
• Example: Frog, Necturus, Toad, Ichthyophis, Salamander.

Concept-

• The frog's most common species is Rana tigrina.
• Frog has the ability to change their color to hide from their enemies (camouflage).
• The frog never drinks water but absorbs it through the skin.
• Frogs also go into hibernation (winter sleep) and aestivation (summer sleep).
• Frogs are cold-blooded ( their body temperature varies with the temperature).
• The frog body is divided into two parts- Head and trunk.

Explanation-

• The nervous system is divided into 3 parts-
  • (1) Central nervous system (2) Peripheral nervous system (3) Autonomous nervous system
• The peripheral nervous system is made up of cranial nerves and spinal nerves.

10 pairs of cranial nerves are present in frogs i.e. 20 cranial nerves.

Additional Information

• 10 pairs of spinal nerves are present in frogs. 
• 10 vertebrae are present in the frog.
• Sexual dimorphism is present in frogs.
• Frogs are beneficial for mankind because they eat insects and protect the crop.

Explanation:

Intercalated discs are the characteristics of Cardiac muscles.

• Cardiac Muscle Tissues are shorter and striped. They usually contain only one nucleus, which is located in the central region of the cell.
• Cardiac Muscle Tissues also possess many mitochondria and myoglobin.
• Cardiac Muscle Tissue cells also are extensively branched and are connected at their ends by intercalated discs.
• An intercalated disc allows the cardiac muscle cells to contract in a wave-like pattern so that the heart can work as a pump.

Additional Information

• Smooth muscles: They are called smooth or visceral muscles because they are found in the visceral organ of the body. They are non-striated and involuntary.
• Skeletal muscles: Fibres of skeletal muscle tissue are long, straight and unbranched. They are voluntary means they can be controlled. It supports internal organ
• It helps to move the head, trunk, limbs, facial expression, eating, etc.
• Sphincter muscles: A sphincter is a circular muscle that normally maintains constriction of a natural body passage or orifice and which relaxes as required by normal physiological functioning.
• Sphincters are found in many animals

• Excretion is the process of removal of nitrogenous wastes from the body of an organism.
• Nitrogenous waste can be divided into three groups based on its toxicity.

1. Ammonia – animals secreting ammonia are called Ammoneotelic
2. Urea - animals secreting urea are called Ureotelic
3. Uric acid - animals secreting uric acid are called Uricotelic

• Ammonia is a water-soluble highly toxic nitrogenous waste, and it requires plenty of water for its removal
• Frog’s Tadpole is aquatic and lives in water so, nitrogenous wastes are eliminated in the form of ammonia.
• Adult frog has an amphibian habitat so it requires a lower amount of water for its waste removal, so the waste is removed in the form of Urea.

Key Points

• Syncytium refers to a single cell mass containing numerous nuclei, usually caused due to fusion of cells.
• Muscles are divided into 3 major classes:

Important Points

• Cardiac muscle look like syncytium but histologically it is not syncytium: Assertion is TRUE
  • It does look like a syncytium with multiple nucleus.
  • From the above table we see that cardiac muscles are uninucleate.
  • Thus, it cannot be a syncytium histologically.
• Reason is TRUE
  • Cardiac muscle fibers are joined end-to-end by flat zig-zag junctions called intercalated discs.
  • The fibers are interconnected by oblique bridges, forming a network.
  • This gives the look of a syncytium, but they are actually individual fibers.
  • They are also branched muscle fibers with interdigitation.
  • Each fibre has a centrally located nucleus and covered by a special covering sarcolemma.

Concept:

• Animal tissues are different and are broadly classified into four types : (i) Epithelial, (ii) Connective, (iii) Muscular, and (iv) Neural
• Epithelial tissue provides a covering or a lining for some parts of the body.
• Connective tissues are most abundant and widely distributed in the body of complex animals. 
• Muscle is made of many long, cylindrical fibers arranged in parallel arrays. They are three types, skeletal, smooth, and cardiac.
• Neural tissue exerts the greatest control over the body’s responsiveness to changing conditions.

Explanation:

• Ciliated epithelium is mainly present on the inner surface of hollow organs like bronchioles and fallopian tubes. The function is to move particles or mucus in a specific direction over the epithelium.
• Some of the columnar or cuboidal cells get specialized for secretion and are called the glandular epithelium. They are mainly of two types: unicellular, consisting of isolated glandular cells (goblet cells of the alimentary canal), and multicellular, consisting of clusters of cells (salivary gland).
• Tendons are dense regular connective tissues. They attach skeletal muscles to bones.
• Adipose tissue is a type of loose connective tissue located mainly beneath the skin. The cells of this tissue are specialized to store fats.
• Therefore, the correct answer is option 2.

The correct answer is Removal of dust particle from trachea

Explanation: 

• Ciliary movement is characterized by the coordinated, wave-like motions of cilia, which are hair-like structures on the surface of certain cells.
• In the respiratory tract, ciliary movement helps to remove dust and other particles from the trachea by moving mucus up towards the throat where it can be swallowed or expelled. This is an important mechanism for keeping the airways clear.