Part 6 — Nervous System of Frog (Q126–150)

Q126.

The nervous system of frog is:
A. Diffused type
B. Nerve net type
C. Central nervous system with brain and spinal cord ✅
D. Only peripheral nerves

Explanation:

A. Diffused type: Seen in lower animals like coelenterates.
B. Nerve net type: Found in Hydra.
C. CNS with brain and spinal cord (Correct): Frogs have a well-developed CNS.
D. Only peripheral nerves: Incomplete, PNS is present but controlled by CNS.

Q127.

The frog’s brain is enclosed in:
A. Cartilaginous cranium
B. Bony cranium ✅
C. Chitinous case
D. None

Explanation:

A. Cartilaginous cranium: True in fishes and early vertebrates.
B. Bony cranium (Correct): Frogs have a skull enclosing brain.
C. Chitinous case: Found in invertebrates.
D. None: Incorrect.

Q128.

Which part of frog’s brain controls balance and body posture?
A. Cerebrum
B. Cerebellum ✅
C. Medulla oblongata
D. Olfactory lobe

Explanation:

A. Cerebrum: Controls intelligence and voluntary actions.
B. Cerebellum (Correct): Coordinates muscular activity and balance.
C. Medulla oblongata: Involuntary activities like heartbeat, respiration.
D. Olfactory lobe: Sense of smell.

Q129.

The brain of frog is divided into how many main parts?
A. 2
B. 3 ✅
C. 4
D. 5

Explanation:

A. 2: Incorrect.
B. 3 (Correct): Forebrain, midbrain, hindbrain.
C. 4: Not standard.
D. 5: Found in higher vertebrates with subdivisions.

Q130.

The forebrain of frog includes:
A. Cerebrum and olfactory lobes ✅
B. Optic lobes only
C. Cerebellum only
D. Medulla only

Explanation:

A. Cerebrum + olfactory lobes (Correct): True components of frog forebrain.
B. Optic lobes: Midbrain.
C. Cerebellum: Hindbrain.
D. Medulla: Hindbrain.

Q131.

The optic lobes in frogs are part of:
A. Forebrain
B. Midbrain ✅
C. Hindbrain
D. Spinal cord

Explanation:

A. Forebrain: Incorrect.
B. Midbrain (Correct): Optic lobes form the midbrain, responsible for vision reflexes.
C. Hindbrain: Cerebellum + medulla.
D. Spinal cord: Not part of brain.

Q132.

Which part of frog brain regulates heartbeat and respiration?
A. Cerebrum
B. Optic lobes
C. Medulla oblongata ✅
D. Olfactory lobes

Explanation:

A. Cerebrum: Controls voluntary activities.
B. Optic lobes: Vision reflexes.
C. Medulla oblongata (Correct): Controls involuntary functions like heart rate and breathing.
D. Olfactory lobes: Smell.

Q133.

The cranial nerves in frogs are:
A. 8 pairs
B. 10 pairs ✅
C. 12 pairs
D. 6 pairs

Explanation:

A. 8 pairs: Too few.
B. 10 pairs (Correct): Frogs have 10 cranial nerve pairs.
C. 12 pairs: Seen in mammals.
D. 6 pairs: Too few.

Q134.

The spinal nerves in frogs are:
A. 6 pairs
B. 8 pairs
C. 10 pairs
D. 10 pairs arising from spinal cord ✅

Explanation:

A. 6 pairs: Too few.
B. 8 pairs: Incorrect.
C. 10 pairs: Correct, but must specify spinal origin.
D. 10 pairs arising from spinal cord (Correct): Exact statement.

Q135.

Which part of frog brain is least developed compared to mammals?
A. Cerebrum ✅
B. Optic lobes
C. Cerebellum
D. Medulla

Explanation:

A. Cerebrum (Correct): Poorly developed in frogs compared to higher vertebrates.
B. Optic lobes: Well-developed in frogs.
C. Cerebellum: Small but functional.
D. Medulla: Adequately developed.

Q136.

Which one of the following connects brain to spinal cord?
A. Cerebrum
B. Cerebellum
C. Medulla oblongata ✅
D. Optic lobes

Explanation:

A. Cerebrum: Not connected to spinal cord.
B. Cerebellum: No direct connection.
C. Medulla (Correct): Extends into spinal cord.
D. Optic lobes: Only visual center.

Q137.

Which lobe of frog brain is associated with smell?
A. Olfactory lobes ✅
B. Cerebrum
C. Optic lobes
D. Cerebellum

Explanation:

A. Olfactory lobes (Correct): Detect odors.
B. Cerebrum: Higher functions, not smell.
C. Optic lobes: Vision.
D. Cerebellum: Balance.

Q138.

The nervous system in frogs consists of:
A. CNS only
B. CNS + PNS ✅
C. CNS + ANS
D. Nerve net

Explanation:

A. CNS only: Incomplete.
B. CNS + PNS (Correct): Central and peripheral nervous system.
C. CNS + ANS: ANS is absent in frogs.
D. Nerve net: In cnidarians.

Q139.

The function of cerebrum in frogs is:
A. Control of balance
B. Intelligence and voluntary activities ✅
C. Visual reflexes
D. Breathing

Explanation:

A. Balance: Cerebellum.
B. Intelligence + voluntary actions (Correct): Cerebrum.
C. Visual reflexes: Optic lobes.
D. Breathing: Medulla.

Q140.

The cerebrospinal fluid in frog:
A. Fills the body cavity
B. Surrounds digestive tract
C. Fills brain ventricles and spinal canal ✅
D. Absent

Explanation:

A. Body cavity fluid is coelomic fluid.
B. Not around digestive tract.
C. Brain ventricles + spinal canal (Correct): CSF function.
D. Not absent.

Q141.

How many ventricles are present in frog brain?
A. 1
B. 2 ✅
C. 3
D. 4

Explanation:

A. 1: Incorrect.
B. 2 (Correct): Lateral ventricles present in frog brain.
C. 3: Found in humans.
D. 4: Found in mammals.

Q142.

Which part of frog brain controls optic reflexes?
A. Olfactory lobes
B. Cerebrum
C. Optic lobes ✅
D. Cerebellum

Explanation:

A. Olfactory lobes: Smell.
B. Cerebrum: Voluntary actions.
C. Optic lobes (Correct): Visual reflexes.
D. Cerebellum: Balance.

Q143.

Which is NOT a function of frog’s medulla oblongata?
A. Controls heartbeat
B. Controls respiration
C. Controls visual reflex ✅
D. Controls swallowing

Explanation:

A. Heartbeat: Yes, medulla controls.
B. Respiration: Yes.
C. Visual reflex (Correct): Done by optic lobes.
D. Swallowing: Yes, medulla controls.

Q144.

The peripheral nervous system in frogs includes:
A. Brain and spinal cord
B. Cranial and spinal nerves ✅
C. Only cranial nerves
D. Nerve net

Explanation:

A. CNS = brain + spinal cord.
B. PNS = cranial + spinal nerves (Correct).
C. Only cranial nerves: Incomplete.
D. Nerve net: Not in vertebrates.

Q145.

Which of the following nerves in frogs is largest?
A. Olfactory
B. Optic
C. Sciatic ✅
D. Vagus

Explanation:

A. Olfactory: Small, for smell.
B. Optic: For vision.
C. Sciatic (Correct): Thickest, supplies hindlimbs.
D. Vagus: Important but not largest.

Q146.

The spinal cord of frog is:
A. Solid and dorsal
B. Hollow and dorsal ✅
C. Solid and ventral
D. Hollow and ventral

Explanation:

A. Solid dorsal: False.
B. Hollow dorsal (Correct): Spinal cord has central canal, dorsal.
C. Solid ventral: In invertebrates.
D. Hollow ventral: Wrong.

Q147.

The spinal cord in frog extends up to:
A. Cloaca ✅
B. Tail
C. Heart
D. Forelimbs

Explanation:

A. Cloaca (Correct): Spinal cord runs up to cloacal region.
B. Tail: Frogs don’t have adult tails.
C. Heart: Not true.
D. Forelimbs: Not true.

Q148.

Which of the following is absent in frog brain but present in mammals?
A. Olfactory lobes
B. Cerebrum
C. Pons varolii ✅
D. Medulla oblongata

Explanation:

A. Olfactory lobes: Present.
B. Cerebrum: Present, though small.
C. Pons varolii (Correct): Absent in frog.
D. Medulla oblongata: Present.

Q149.

Which sense organ in frog is well developed for vision?
A. Lateral line organ
B. Tympanum
C. Eyes ✅
D. Nose

Explanation:

A. Lateral line: Absent in adult frogs.
B. Tympanum: Hearing.
C. Eyes (Correct): Vision is well developed.
D. Nose: For smell.

Q150.

Which one is NOT correctly matched in frog nervous system?
A. Olfactory lobes – smell
B. Optic lobes – vision
C. Cerebellum – balance
D. Cerebrum – respiration ✅

Explanation:

A. Olfactory lobes → smell: Correct.
B. Optic lobes → vision: Correct.
C. Cerebellum → balance: Correct.
D. Cerebrum → respiration (Correct answer, incorrect match): Respiration is controlled by medulla, not cerebrum.

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Part 6 — Nervous System of Frog (Q126–150)