Syllabus Edition

First teaching 2023

First exams 2025

|

Neural Signalling (HL IB Biology)

Exam Questions

3 hours35 questions
1
Sme Calculator
1 mark

Between which structures do sensory neurones transmit electrical impulses?

  • From effectors to the central nervous system (CNS).

  • From effectors to receptors.

  • From receptors to effectors.

  • From receptors to the central nervous system (CNS).

Did this page help you?

2
Sme Calculator
1 mark

Where would myelin be found?BvBrUXey_e-2

    Did this page help you?

    3
    Sme Calculator
    1 mark

    Which event directly results in the production of an action potential?

    • Diffusion of neurotransmitter across the synaptic cleft.

    • Fusion of vesicles with the presynaptic membrane.

    • Membrane potential reaches the resting potential.

    • Membrane potential reaches the threshold potential.

    Did this page help you?

    4
    Sme Calculator
    1 mark

    Identify where depolarisation is occurring.

    WwYY3DDn_e-4

      Did this page help you?

      5
      Sme Calculator
      1 mark

      Neurotransmitters leave the presynaptic neurone and enter the synaptic cleft. After this, they travel across the cleft to a receptor on the postsynaptic neurone membrane.

      Identify the processes that are required for this to occur.

        Neurotransmitters enter synaptic cleft Neurotransmitters travel across cleft
      A. Endocytosis Diffusion
      B. Endocytosis Active transport
      C. Exocytosis Diffusion
      D. Exocytosis Active transport

        Did this page help you?

        1
        Sme Calculator
        1 mark

        The following graph shows an action potential in a mouse neurone after stimulation with a pulse of current.~1zH4BNF_1

        What is the threshold potential needed to open voltage gated sodium channels in this neurone?

        • -70mV

        •  -50mV

        • -30mV

        • +50mV

        Did this page help you?

        2
        Sme Calculator
        1 mark

        The opening of axon membrane voltage gated potassium channels are responsible for which part of the action potential?

        • Repolarisation of the membrane.

        • Depolarisation of the membrane.

        • Hyperpolarisation of the membrane.

        • Signalling vesicular release of neurotransmitters.

        Did this page help you?

        3
        Sme Calculator
        1 mark

        It is thought that conditions such as schizophrenia are caused by an overabundance of the neurotransmitters serotonin and dopamine in some regions of the brain.

        Given this is the case, which drug mode of action could work in treating symptoms of schizophrenia?

        • Increased permeability of the presynaptic neurone to calcium.

        • Increased reuptake of serotonin and dopamine by pre synaptic neurones.

        • Release of acetylcholinesterase into the presynaptic cleft.

        • Blockage of serotonin and dopamine receptors in postsynaptic neurones.

        Did this page help you?

        4
        Sme Calculator
        1 mark

        Which of the following statements about myelinated nerve fibres are correct?

        1. Nodes of Ranvier facilitate saltatory conduction. 
        2. Schwann cells are responsible for forming the myelin sheath.
        3. The myelin sheath acts as an electrical conductor allowing electrical impulses to conduct at a more rapid rate.
        • II only

        • I and II only

        • II and III only

        • I, II, and III

        Did this page help you?

        5
        Sme Calculator
        1 mark

        The diagram below shows the change in membrane potential during an action potential.

        aYIW_ZrM_2

        Which of the following best describes the events indicated by the label X?

         

          Sodium channels Potassium channels Membrane potential
        A open closed decreasing
        B closed open increasing
        C closed open decreasing
        D open closed increasing

          Did this page help you?

          6
          Sme Calculator
          1 mark

          The diagram below shows a sensory neurone connected to its associated receptor cells.

          zVkh1w6k_3

           Which best describes the function of the structure labelled A?

          • Contains most cellular structures

          • Acts as an electrical insulator

          • Transmit impulses to the spinal cord

          • Transmit and recieve impulses to other neurones

          Did this page help you?

          7
          Sme Calculator
          1 mark

          The diagram below shows a sodium-potassium pump within the axon membrane of a neurone.

          nDcY0Z0__4

          What is the role of active transport in the transmission of nerve impulses by neurones?

          • Establishes the resting potential needed for impulse transmission by pumping sodium ions out of the axon and potassium ions into the axon.

          • Depolarisation of the axon by moving sodium ions across the membrane into neurone.

          • Establishes the resting potential needed for impulse transmission by moving sodium ions into the axon and potassium ions out of the axon.

          • Initiates the action potential needed for the transmission of an impulse by pumping calcium ions into the axon.

          Did this page help you?

          8
          Sme Calculator
          1 mark

          Which line of the table represents a neurone at its resting potential?

            Concentration of ions inside neurone Cell surface membrane permeability to Na⁺ Level of activity of Na⁺/K⁺ pump
          Sodium (Na⁺) Potassium (K⁺)
          A high low high active
          B high low low inactive
          C low high high inactive
          D low high low active

           

            Did this page help you?

            9
            Sme Calculator
            1 mark

            Membrane channel proteins are essential for the normal functioning of nerves.

            Which process in nerves does not require a membrane protein?

            • Active transport of sodium.

            • Depolarisation during an action potential.

            • Binding of neurotransmitters.

            • Diffusion of neurotransmitters.

            Did this page help you?

            10
            Sme Calculator
            1 mark

            The use of pesticides is a cause of controversy due to its impact on pollinators such as bees.

            What effect do these pesticides have on the nervous system of insects?

            • They prevent acetylcholinesterase from breaking down acetylcholine.

            • They inhibit depolarisation in the presynaptic neurone which increases the level of acetylcholine.

            • They block synaptic transmission by binding with postsynaptic acetylcholine receptors.

            • They produce an inhibitor that promotes the binding of acetylcholine.

            Did this page help you?

            1
            Sme Calculator
            1 mark

            Neonicotinoids are synthetic compounds similar to nicotine that are commonly found in pesticides. Neonicotinoids are considered to be especially suitable as pesticides because they're not toxic to humans and other mammals.

            Which statements I - IV are the reasons for this?

            I. A larger proportion of synapses in insects are cholinergic compared to mammals.

            II. Neonicotinoids are more effective at preventing acetylcholinesterase from breaking down acetylcholine in insects compared to mammals.

            III. Acetylcholinesterase in insects cannot break down neonicotinoids.

            IV. Neonicotinoids bind more strongly to acetylcholine receptors in insects.

            • I and IV

            • I, II and IV

            • II and III

            • II only

            Did this page help you?

            2
            Sme Calculator
            1 mark

            The diagram below shows the left to right transmission of an action potential in a myelinated axon by saltatory conduction.qeahNoHs_h-2

            Which of the following rows correctly identifies I - IV?

              I II III IV
            A. Node at resting potential Node at action potential Node at refractory period Node becoming depolarised
            B. Node at refractory period Node at action potential Node becoming depolarised Node at resting potential
            C. Node at action potential Node at refractory period Node becoming depolarised Node at resting potential
            D. Node at refractory period Node becoming depolarised Node at action potential Node at resting potential

              Did this page help you?

              3
              Sme Calculator
              1 mark

              The oscilloscope trace shown below was taken using a digital oscilloscope. It shows an action potential in a hippocampal pyramidal neurone of a potoroo (a small marsupial species) that occurred when the neurone was stimulated with a current pulse.Nl4mPzfI_h-3

              How many action potentials could be stimulated in this neurone every second?

              • 6

              • 60

              • 12

              • 7

              Did this page help you?

              4
              Sme Calculator
              1 mark

              A research group of geneticists found a fruit fly mutant that shakes vigorously when anaesthetized with ether. Their studies showed that the shaker mutant has K+ channels that do not function properly. An action potential of a normal fruit fly and a shaker mutant is shown below.

              FLaRvWOD_h-4

              Which of the following statements (I - IV) could be possible explanations for the differences between the action potentials?

              I. The faulty K+ channels don't open for as long so there is slower diffusion of K+ ions.

              II. The faulty K+ channels may be opening early, preventing maximum depolarisation.

              III. The faulty K+ channels cause K+ ions to diffuse back into the axon more slowly, resulting in slower repolarisation.

              IV. In wild-type drosophila, the functioning K+ channels allow for a faster rate of depolarisation.

              • I only

              • II and III

              • I, II and IV

              • I and II

              Did this page help you?

              5
              Sme Calculator
              1 mark

              Study the diagram below.X3IhGrSh_h-5

              Which of the following table rows correctly identifies I - VI?

                I II III IV V VI
              A. Acetylcholine Acetyl-cholinesterase Cholinergic receptor Choline Acetyl group Acetyl-CoA
              B. Acetyl-cholinesterase Acetyl-CoA Acetylcholine Cholinergic receptor Choline Acetyl group
              C. Acetylcholine Cholinergic receptor Acetyl-cholinesterase Acetyl group Choline Acetyl-CoA
              D. Acetylcholine Cholinergic receptor Acetyl-CoA Choline Acetyl group Acetyl-cholinesterase

                Did this page help you?