Grade 11 : Biology - Neural (Set 3) | Concept of Maths

Question 1

1. A gymnast is performing a complex routine on a balance beam. Which specific part of the hindbrain is primarily responsible for coordinating her muscle movements and maintaining her equilibrium?

A) Medulla Oblongata

B) Cerebellum

C) Pons Varolii

D) Thalamus

Answer

Correct Answer: B

The Cerebellum is the part of the hindbrain that integrates sensory information to regulate motor movements, posture, and balance. While the medulla controls involuntary vitals, the cerebellum ensures precision and coordination.

Question 2

2. During the resting state of a neuron, the axonal membrane is relatively more permeable to $K^{+}$ ions and nearly impermeable to $Na^{+}$ ions. Which statement correctly describes the ion distribution in the axoplasm?

A) High concentration of $Na^{+}$ and low concentration of $K^{+}$

B) Equal concentration of $Na^{+}$ and $K^{+}$

C) High concentration of $K^{+}$ and low concentration of $Na^{+}$

D) Only $Cl^{-}$ ions are present

Answer

Correct Answer: C

In a resting neuron, the axoplasm (inside the axon) contains high concentrations of $K^{+}$ and negatively charged proteins, while having a low concentration of $Na^{+}$. This is maintained by the active transport mechanism.

Question 3

3. The Sodium-Potassium pump is a vital active transport mechanism. For every cycle of ATP hydrolysis, how many ions are moved across the membrane?

A) $3$ $Na^{+}$ outward and $2$ $K^{+}$ inward

B) $2$ $Na^{+}$ outward and $3$ $K^{+}$ inward

C) $3$ $Na^{+}$ inward and $2$ $K^{+}$ outward

D) $1$ $Na^{+}$ outward and $1$ $K^{+}$ inward

Question 4

4. At a chemical synapse, the arrival of an action potential at the axon terminal triggers the release of neurotransmitters. Where are these chemicals stored before release?

A) Dendritic spines

B) Myelin sheath gaps

C) Nodes of Ranvier

D) Synaptic vesicles

Answer

Correct Answer: D

Neurotransmitters like acetylcholine are stored in membrane-bound structures called synaptic vesicles located in the synaptic knobs at the axon terminals.

Question 5

5. A researcher is studying a patient who has lost the ability to perceive colors but can still see in dim light. Which specialized cells in the retina are likely dysfunctional?

A) Rod cells

B) Cone cells

C) Bipolar cells

D) Amacrine cells

Answer

Correct Answer: B

The human eye contains two types of photoreceptor cells: rods (for scotopic/dim light vision) and cones (for photopic/daylight and color vision). Loss of color perception points to cone cell dysfunction.

Question 6

6. In a simple reflex arc, such as the knee-jerk reflex, the signal travels from the receptor to the CNS and then to the effector. Which neuron type carries the impulse towards the Spinal Cord?

A) Efferent neuron

B) Motor neuron

C) Afferent (Sensory) neuron

D) Interneuron

Answer

Correct Answer: C

The pathway of a reflex arc is: $$Receptor \rightarrow \text{Afferent Neuron} \rightarrow \text{CNS} \rightarrow \text{Efferent Neuron} \rightarrow Effector$$. The afferent neuron carries sensory data toward the CNS.

Question 7

7. Which region of the forebrain acts as the master regulator for body temperature, hunger, and thirst?

A) Hypothalamus

B) Cerebrum

C) Corpus Callosum

D) Thalamus

Answer

Correct Answer: A

The Hypothalamus contains several centers which control body temperature, urge for eating and drinking, and also secretes hypothalamic hormones.

Question 8

8. The inner ear contains a complex structure responsible for hearing. Where exactly are the hair cells (auditory receptors) located?

A) Semicircular canals

B) Eustachian tube

C) Tectorial membrane

D) Organ of Corti

Answer

Correct Answer: D

The Organ of Corti is a structure located on the basilar membrane of the cochlea. It contains hair cells that act as auditory receptors.

Question 9

9. When a stimulus is applied to a site on the polarized membrane, the membrane becomes freely permeable to $Na^{+}$. This leads to a rapid influx of $Na^{+}$, resulting in:

A) Depolarization

B) Hyperpolarization

C) Repolarization

D) Permanent arrest

Answer

Correct Answer: A

The rapid influx of $Na^{+}$ reverses the polarity at the site (inside becomes positive), a process called depolarization, which creates the action potential ($+30$ to $+40\text{ mV}$).

Question 10

10. During an emergency, which part of the brain stem controls the vital centers for respiration and cardiovascular reflexes?

A) Midbrain

B) Pons

C) Medulla Oblongata

D) Cerebrum

Answer

Correct Answer: C

The Medulla Oblongata contains centers which control respiration, cardiovascular reflexes, and gastric secretions. It is the connection point between the brain and the spinal cord.

Accepted Answer

Correct Answer: A

The $Na^{+}/K^{+}$ ATPase pump operates by transporting: $$\text{3 Na}^{+} (out) + \text{2 K}^{+} (in) + \text{ATP} \rightarrow \text{ADP} + \text{P}_i$$ This electrogenic process contributes to the negative resting potential.

Grade 11 : Biology - Neural (Set 3) | Concept of Maths