What happens if the threshold potential is ny;6c r iel*.9mo6 csxn f:k;bkot reached ?

  At what membrane potential do voltag gf(,i lr,xh f,5fuo7le-gated sodium channels open?

  The diagram shows a neurox.aczflsh / ewe3:07gkqur vgv*.//m n.
Which arrow indicates a dendrite?

  How do neonicotinoid pest6k08 c6aq 2hopjfgi z)icides work?

  The diagram shows an action poth5/c ad*41 t5bqwd*rty3e 5xlt)ffx lential.

What is happening at point X?

  Which is the correct definition of saltatory conductio/e p1oa4vo1rjn?

Neuronal cells have special membrane properties that allow thei,j+ze 2g/ 4 v a9 sks1afd4p3xu9azftqr axons to propagate action potential from one cell to another. The dia3p,aa4gt sqfx21j9v4/ fs+aezkdu9 z gram below shows a portion of an axonal plasma membrane.


1.(1)State the role of a sodium-potassium pump in axon.
(2)Describe the action of the sodium-potassium pump.
2.Distinguish between simple diffusion, facilitated diffusion and active transport.
3.Compare and contrast sodium-potassium pumps and potassium channels.

  What causes the exocytosis of neurotransmitters at the pht g8 rs1t5ve40qg .fnresynaptic membrane?
I. Depolarisation of the postsynaptic membrane
II. Depolarisation of the presynaptic membrane
III. The diffusion of calcium ions

  What are the main factors that maintain a/kuddrk k w8y.35:ju emot 34n neuron’s resting potential?

  What is not a function of the myelin sheath?

Explain how the resting potential is maintained in3ohlawu ft2(q6 6x;mio8 6v8 ogxy* sn a neuron.

The diagram represents a synaptic cleft between two neurons in a3 b*zzmo9 ljonx-u r29n insect's nervous systemoou -z 2 j9bzlnm39*xr.



Gardeners use pesticides that contain neonicotinoids to kill pests. Label with the letter X where neonicotinoids would bind.
1.(1)Explain how neonicotinoids work on insects.
(2)Suggest what the effect would be on synaptic transmission in cholinergic synapses if gardeners used (3)pesticides that were broken down by acetylcholinesterase.
2.Explain why neonicotinoid containing pesticides are less toxic to mammals than insects

1.Draw and label the structyi1lt4q-t z3, nkb i5yure of a typical neuron.
2.Explain why myelination is essential for the rapid transmission of impulses.
3,Explain the importance of positive ions in the generation and propagation of an action potential.

Neonicotinoids are synthetic compoundsq4 3yq2enx)qd/0rnri that are widely used as pesticides. However, there are concerns about their efe irn3q)rx/yq2dn04q fect on honey bees and other pollinating insects. The table below shows the results from a study where honey bees (Apis mellifera carnica) were treated with non-lethal doses of two neonicotinoids, Imidacloprid and Clothianidin, and the effect it had on their homing instinct (ability to fly back to their hive).

1.Describe the mode of action of pesticides containing neonicotinoids on cholinergic synapses in insects.
2.Using the data, outline the effect of the neonicotinoids on honey bees.
3.Calculate the percentage increase between the control and those treated with 0.6 μM of Imidacloprid which did not arrive back at their hive.
4.State what the dependent variable is in this study.
5.(1)Based on the data, predict the effect that exposing honey bees to neonicotinoids will have on the fitness of the honey bee colony.
(2)Explain your answer to part (i).
6.The researchers concluded that neonicotinoids should not be used as pesticides due to their unintended effects on honey bees. Evaluate whether this data supports their conclusion.

  The graph below shows membrane voltcg.juz;5 7uuzage over time during an action potential. Which letter represents the segment of the action potential when voltage-gated sodium channels are open and voltagj zu 7z.5uu;cge-gated potassium channels are closed?

  Which two features are more abundant per unit length in a non-myelinated neuron ot1ft qbbq q4.j. o*6bthan in a myeljo *.btt6o qb4 qf1b.qinated neuron?

  Which of the following is a/are correct description(s) of the relativ 1/3(hqcijy cne speed impulse3 j(1inq /hyccs are conducted at?
I. As the diameter of axons increases, the speed at which impulses are conducted increases.
II. There is a negative correlation between animal size and the speed at which impulses are conducted.
III. Saltatory conduction in myelinated neurons is slower than the speed at which impulses are conducted in non-myelinated neurons.

  The diagram shows a process that n3ezr;p/j9.q b f. grg/nzxv9 occurs in the membranes of neurons during a stage of the action potential. What process does theren9pnz3b fqg.xg;/jz9 v/ r . diagram depict?

  The image shows neurons that are found in dog brains. What does letter X i;3 ap 95(gupy*8 hl leoybp,iindicate? l8 ia(eyi9p;pgu l3ybh*,p5o

  The diagram shows two neurons of equal length and diameter. Which neuron will ihk4r4xe; d t.transfer an electrical impuk.e r44xiht; dlse faster?

  Which triggers the release of neurotransmitters from the presynaptic t8n5pzs.xrv+ membrane?

  Which mode of transport do neurotrangpa-bbvmc :-s )6ah/o o)k /r:ibvw 3bsmitters use to travel across a synapse?

  Which statement explains why a nerve .ob- u25hs vpe(6l raejuct 04impulse is electrical?

1.Explain why a resti9f.9xy ok)8mirc)bpsza g,,5v jy2rzng potential is negative.
2.Explain how the structure of a neuron is adapted to its function.
3.Describe the events that occur to propagate an action potential within a neuron and between two neurons.