What happens if the threshold potential is not re;v5)wvzpg2w : d.yanznf p:84j q7rdvached ?

  At what membrane potential do voll3*4sng4-,ft nj bff htage-gated sodium channels open?

  The diagram shows a l e9ke*gjv idp.0+cg; neuron.
Which arrow indicates a dendrite?

  How do neonicotinoid pesticid baqqg:o.,s 3ves work?

  The diagram shows an act hfn xp a:ac:wu: 7:cz:)l9shzion potential.

What is happening at point X?

  Which is the correct definjni ao l.w;n(7ition of saltatory conduction?

Neuronal cells have special membrane properties that allow thei+zxx5bzvh086nw yr.xcp kf 31r axons to propagate action potential from one cell to another. The diagr0h65rcyvn x1z p+.fb x83xkwzam 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 p.rey7o vnhj(fk y:2z4 resynaptic 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 maintam,; w s*s;u nzf ikzp4 ge:a68;.fmtqtin a neuron’s resting potential?

  What is not a function of the myelin sheath?

Explain how the resting potential is maintained in a neuron(5v ,wd)kzz rb9r5myn.

The diagram represents a synaptic cleft between two neurons inlyx 6d5n(ebrd/a)c*x 7xvz2e an insect's nervous sy dxya e7*l6z)n 5vr bxd/(x2cestem.



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 zb (-u4)yiwvc 0sm6gj m(sv6astructure 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 compounds that are widely usedbeht 3(ks tm08s nj/v* as pesticides. However, there are concerns about their effect on honey bees and other pollinating insects. The table below shows the results from a study where honey bees (Apis metb3(/8jns0 hvks met *llifera 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 voltage ka d2pjln 7:3jover time during an action potential. Which letter represents the segment of the action potential when voltage-gated sodium channels are open and voltage-gated n 3d2:kjlpj 7apotassium channels are closed?

  Which two features are more abundant per ubr)lcx l6tajnuvrvl9 u 4 8o fk).h8,cm .pe56nit length in a non-myelinated neuron than in a myelinatedoh) 5k8 j n cuvlbf6a6ul.r)r4et9mpcxv,l8 . neuron?

  Which of the following is a/are correct des zq )ah1ifqh8.o+,fq*rf jar9cription(s) of the relative speed impulse1 rq ha+.f*o9zafr)hi,f8 jqqs 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 occurs in the membranes of nm5j l wl 84f*wdufc3:rkk,lg,eurons during a stage of the action potentiarf3 kml l:gl u,kj,*5wcdfw84l. What process does the diagram depict?

  The image shows neurons that x/qxjlff5 j *,( ,xlbbare found in dog brains. What does letter X indicate?(/j lx qf*bfj b5,xl,x

  The diagram shows two neurons of equal length and diameter. Which neuron b-g 6f53yj ib, 5rmttaxmd t2-will transfer an electrical impulse faster?d-2mfa5rgtbytx j5mi,6 -3 t b

  Which triggers the release of neu7u;6cy3m :l u a*8zeg5h9ef.hclc mn crotransmitters from the presynaptic membrane?

  Which mode of transport do neurotransmitters ug w;cn.c-6;y2ehoau h se to travel across a synapse?

  Which statement explains why a nerve impulse iscl x77b u lct9w/w:nl+ electrical?

1.Explain why a resting potential is negat 9xoju 6.l)uybive.
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.