Level 1 — RecognitionNervous System

Nervous System

⏱ 20 minutes30 marksprintable — key stays hidden on paper

Level 1: Recognition Test

Time Limit: 20 minutes Total Marks: 30

Section A — Multiple Choice (1 mark each)

Choose the single best answer.

Q1. The part of a neuron that receives incoming signals from other neurons is the:

(a) axon
(b) dendrite
(c) soma
(d) synaptic knob

Q2. A neuron that carries impulses from the central nervous system toward a muscle is a:

(a) sensory neuron
(b) interneuron
(c) motor neuron
(d) receptor neuron

Q3. The resting membrane potential of a typical neuron is approximately:

(a) $+30\ \text{mV}$
(b) $0\ \text{mV}$
(c) $-70\ \text{mV}$
(d) $-90\ \text{mV}$

Q4. During the depolarisation phase of an action potential, the ion that rushes INTO the neuron is:

(a) $K^+$
(b) $Na^+$
(c) $Cl^-$
(d) $Ca^{2+}$

Q5. The insulating myelin sheath in the peripheral nervous system is produced by:

(a) astrocytes
(b) microglia
(c) Schwann cells
(d) oligodendrocytes

Q6. Saltatory conduction refers to the action potential:

(a) travelling continuously along the whole membrane
(b) "jumping" between the nodes of Ranvier
(c) moving backward along the axon
(d) crossing the synaptic cleft

Q7. At a chemical synapse, the neurotransmitter is released from the presynaptic terminal into the:

(a) axon hillock
(b) node of Ranvier
(c) synaptic cleft
(d) soma

Q8. Which structures make up the central nervous system (CNS)?

(a) brain and spinal cord
(b) cranial and spinal nerves
(c) sensory receptors and ganglia
(d) sympathetic and parasympathetic nerves

Q9. The brain region responsible for coordinating balance and fine motor movement is the:

(a) cerebrum
(b) cerebellum
(c) medulla oblongata
(d) hypothalamus

Q10. In a simple reflex arc, the correct order of components is:

(a) receptor → motor neuron → interneuron → sensory neuron → effector
(b) effector → sensory neuron → interneuron → motor neuron → receptor
(c) receptor → sensory neuron → interneuron → motor neuron → effector
(d) receptor → interneuron → sensory neuron → motor neuron → effector

Q11. The division of the nervous system under voluntary control of skeletal muscle is the:

(a) autonomic system
(b) somatic system
(c) sympathetic system
(d) enteric system

Q12. Activation of the sympathetic division typically causes:

(a) increased heart rate and pupil dilation
(b) decreased heart rate and increased digestion
(c) pupil constriction and salivation
(d) bladder emptying and slowed breathing

Q13. Light-sensitive photoreceptors of the eye are found in the:

(a) cornea
(b) lens
(c) retina
(d) iris

Section B — Matching (1 mark each)

Q14–Q18. Match each structure/term (left) to its function (right). Write the letter next to the number.

#	Term		Function
14	Axon	A	Detects sound / balance in the inner ear
15	Sodium–potassium pump	B	Conducts the impulse away from the soma
16	Interneuron	C	Maintains ion gradients across the membrane
17	Cochlea	D	Connects sensory and motor neurons within the CNS
18	Hypothalamus	E	Regulates body temperature, hunger, and homeostasis

(5 marks total)

Section C — True/False WITH Justification (2 marks each)

State True or False (1 mark) and give a one-sentence justification (1 mark).

Q19. "The action potential is a graded signal that can be large or small depending on stimulus strength."

Q20. "Myelination speeds up impulse conduction along an axon."

Q21. "The parasympathetic division prepares the body for 'fight or flight'."

Q22. "Neurotransmitters cross the synaptic cleft by active transport using ATP."

Answer keyMark scheme & solutions

Section A (1 mark each)

Q1 — (b) dendrite. Dendrites are branched projections specialised to receive signals; the axon transmits them. ✔ 1 mark

Q2 — (c) motor neuron. Motor (efferent) neurons carry impulses from the CNS to effectors (muscles/glands). ✔ 1 mark

Q3 — (c) $-70\ \text{mV}$ . The inside is negative relative to outside at rest due to ion distribution and membrane permeability. ✔ 1 mark

Q4 — (b) $Na^+$ . Voltage-gated $Na^+$ channels open, and $Na^+$ flows in down its gradient causing depolarisation. ✔ 1 mark

Q5 — (c) Schwann cells. In the PNS Schwann cells form myelin; oligodendrocytes do this in the CNS. ✔ 1 mark

Q6 — (b) "jumping" between the nodes of Ranvier. The impulse regenerates only at unmyelinated nodes, speeding conduction. ✔ 1 mark

Q7 — (c) synaptic cleft. Vesicles release neurotransmitter into the gap between pre- and postsynaptic membranes. ✔ 1 mark

Q8 — (a) brain and spinal cord. The CNS = brain + spinal cord; nerves/ganglia are the PNS. ✔ 1 mark

Q9 — (b) cerebellum. The cerebellum coordinates balance, posture, and fine movement. ✔ 1 mark

Q10 — (c) receptor → sensory neuron → interneuron → motor neuron → effector. This is the standard reflex-arc pathway. ✔ 1 mark

Q11 — (b) somatic system. The somatic nervous system controls voluntary skeletal muscle movement. ✔ 1 mark

Q12 — (a) increased heart rate and pupil dilation. Sympathetic = "fight or flight" responses. ✔ 1 mark

Q13 — (c) retina. Rods and cones (photoreceptors) line the retina. ✔ 1 mark

Section B — Matching (1 mark each)

#	Answer	Reason
14	B	Axon conducts impulse away from the soma
15	C	Na⁺/K⁺ pump maintains the ion gradients
16	D	Interneurons link sensory and motor neurons in CNS
17	A	Cochlea detects sound in the inner ear
18	E	Hypothalamus regulates homeostasis

(5 marks)

Section C — True/False + Justification (2 marks each)

Q19 — False (1). Justification (1): The action potential is all-or-none; once threshold is reached its amplitude is fixed and does not vary with stimulus strength (stimulus intensity is coded by frequency). ✔

Q20 — True (1). Justification (1): Myelin insulates the axon and forces the impulse to jump between nodes of Ranvier (saltatory conduction), greatly increasing conduction speed. ✔

Q21 — False (1). Justification (1): The sympathetic division mediates fight-or-flight; the parasympathetic promotes "rest and digest." ✔

Q22 — False (1). Justification (1): Neurotransmitters cross the cleft by diffusion down a concentration gradient, not by active transport. ✔

Total: 13 (A) + 5 (B) + 8 (C) = 30 marks

[
  {"claim":"Resting potential -70 mV is negative (inside relative to outside)","code":"resting_mV = -70\nresult = (resting_mV < 0)"},
  {"claim":"Section A has 13 one-mark questions totalling 13 marks","code":"sectionA = 13*1\nresult = (sectionA == 13)"},
  {"claim":"Full paper totals 30 marks","code":"total = 13*1 + 5*1 + 4*2\nresult = (total == 30)"},
  {"claim":"Section C: 4 questions x 2 marks = 8 marks","code":"result = (4*2 == 8)"}
]