Consider the following statements regarding the posterior brain connections and spinal cord protection:
I. The medulla oblongata is a primary component of the fore-brain. II. The medulla oblongata passes out of the cranium through a large opening called the foramen magnum. III. After exiting the cranium, the medulla oblongata continues posterior-wards as the spinal cord. IV. The spinal cord is safely enclosed and protected within the vertebral column.
Explanation: Statement I is incorrect because the medulla oblongata is a part of the hind-brain. Statement II is correct because it passes through the foramen magnum. Statement III is correct because it continues as the spinal cord. Statement IV is correct because the spinal cord is enclosed within the vertebral column.
Question 62 of 101
📘 CLASS XI
Consider the following statements regarding the sensory structures of the frog:
I. Organs of touch are represented by sensory papillae. II. Organs of taste are represented by taste buds. III. Organs of smell are represented by the nasal epithelium. IV. All of these sense organs (touch, taste, and smell) are highly complex, well-organized organs in the frog.
Explanation: Statements I, II and III are correct. Sensory papillae act as organs of touch, taste buds function as organs of taste, and the nasal epithelium functions as the organ of smell. Statement IV is incorrect because these are simple cellular aggregations around nerve endings and are not highly organized sensory organs.
Question 63 of 101
📘 CLASS XI
Analyze the distinction between well-organized and simple sensory structures in frogs:
I. Eyes and internal ears represent the only well-organized sensory structures in the frog. II. The simple sensory structures are cellular aggregations around nerve endings. III. Eyes in a frog are simple eyes that possess only a single unit. IV. Eyes in a frog are compound structures consisting of several visual units.
Explanation: Statements I, II and III are correct. Eyes and internal ears are the only well-organized sensory structures, while touch, taste and smell are simple cellular aggregations around nerve endings. Frog eyes are simple eyes with a single visual unit. Statement IV is incorrect because frogs do not possess compound eyes.
Question 64 of 101
📘 CLASS XI
Consider the following statements regarding the external and internal auditory anatomy of the frog:
I. An external ear pinna is clearly visible on the lateral side of the head. II. External ears are absent in frogs; only the tympanum can be seen externally. III. The ear in the frog functions strictly as an organ of hearing. IV. The ear serves a dual role: as an organ of hearing and as an organ of balancing (equilibrium).
Explanation: Statement I is incorrect because frogs lack external ears. Statement II is correct because only the tympanum is externally visible. Statement III is incorrect because the ear performs both hearing and balancing functions. Statement IV is correct because the internal ear is responsible for hearing as well as equilibrium.
Question 65 of 101
📘 CLASS XI
Analyze the structural characteristics and attachment of the male reproductive organs (testes) in frogs:
I. Male reproductive organs consist of a pair of yellowish, ovoid testes. II. The testes are found adhered to the upper part of the kidneys. III. Testes are attached to the kidneys by a double fold of peritoneum called the mesorchium. IV. Testes have no anatomical connection with the kidneys and exist independently in the lower body cavity.
Explanation: Statements I, II and III are correct. The testes are yellowish, ovoid structures attached to the upper part of the kidneys by a double fold of peritoneum called the mesorchium. Statement IV is incorrect because the testes are anatomically connected with the kidneys.
Question 66 of 101
📘 CLASS XI
Consider the following statements regarding the number and pathway of vasa efferentia inside the frog's kidney:
I. Vasa efferentia are 10–12 in number and arise directly from the testes. II. Vasa efferentia enter the kidneys on their respective side. III. Upon entering the kidneys, vasa efferentia open into Bidder's canal. IV. Vasa efferentia bypass the kidneys entirely to open directly into the urinary bladder.
Explanation: Statements I, II and III are correct. About 10–12 vasa efferentia arise from each testis, enter the kidneys and open into Bidder's canal. Statement IV is incorrect because they pass through the kidney before joining the urinogenital duct and never open directly into the urinary bladder.
Question 67 of 101
📘 CLASS XI
Consider the following statements regarding the urinogenital duct of male frogs:
I. Bidder's canal communicates directly with the urinogenital duct. II. The urinogenital duct comes out of the kidneys and opens into the cloaca. III. The duct is called a urinogenital duct because it carries both urine and sperms in male frogs. IV. Male frogs have separate ureters and sperm ducts opening independently into the cloaca.
Explanation: Statements I, II and III are correct. Bidder's canal communicates with the urinogenital duct, which emerges from the kidney and opens into the cloaca while carrying both urine and sperms. Statement IV is incorrect because male frogs do not possess separate sperm ducts; the ureter functions as the common urinogenital duct.
Question 68 of 101
📘 CLASS XI
Analyze the anatomical nature and functional roles of the cloaca in frogs:
I. The cloaca is a small, median chamber. II. It is used to pass digested faecal matter to the exterior. III. It is used to pass urine to the exterior. IV. It is used to pass sperms (in males) or ova (in females) to the exterior.
Explanation: All four statements are correct. The cloaca is a small median chamber that serves as the common passage for faeces, urine, and reproductive products (sperms in males and ova in females) before they are discharged to the exterior.
Question 69 of 101
📘 CLASS XI
Consider the following statements regarding the ovaries and oviducts of the female frog:
I. Female reproductive organs include a pair of ovaries situated near the kidneys. II. Ovaries maintain a close, functional urinogenital relationship with the kidneys, similar to the male testes. III. There is no functional connection between the ovaries and the kidneys. IV. A pair of oviducts arising from the ovaries opens into the cloaca separately.
Explanation: Statement I is correct because the ovaries are situated near the kidneys. Statement II is incorrect because, unlike the male reproductive system, the ovaries have no functional connection with the kidneys. Statement III is correct because the urinary and reproductive systems remain functionally separate in females. Statement IV is correct because the paired oviducts open separately into the cloaca.
Question 70 of 101
📘 CLASS XI
Analyze the statements regarding spawning capacity, fertilization site, and development in female frogs:
I. A mature female frog can lay 2,500 to 3,000 ova at a time. II. Fertilisation in frogs is internal and takes place within the female's oviducts. III. Fertilisation is external and takes place in water. IV. Development is indirect, involving a larval stage called a tadpole.
Explanation: Statement I is correct because a mature female frog lays about 2,500 to 3,000 ova at a time. Statement II is incorrect because fertilisation is external. Statement III is correct because fertilisation occurs in water. Statement IV is correct because development is indirect and includes a tadpole larval stage.
