What happens if the threshold potential zvh kaezxuvs skn01 ao9 )6mej4;;4y5 is not reached ?

  At what membrane potential do fa70fu95xehm u4sz zq7w)t0y 5 )erk cvoltage-gated sodium channels open?

  The diagram shows a neuron. i*f 5gyrou :/f1+ucwd4 .f;t zy(zu j wk4bbe,
Which arrow indicates a dendrite?

  How do neonicotinoid pesticideszwx -5yq5 ipr( work?

  The diagram shows an action potejhqh*rd9y;1n i9vg6 9jbxgt+ ntial.

What is happening at point X?

  Which is the correct k(h bun /h(5figpft i6gfhz9l;7wz, (definition of saltatory conduction?

Neuronal cells have special membrane properties that allow their axon*dmafk)p:n5b-7s ash s to propagate action potential from one cell to another. The diagram below shds h7m-a:*5a )p nbkfsows 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 ne3r4 c j)a30/e db0aplf h0soetd32hpsurotransmitters at the presynaptic 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 neuron’s resting potential?0bgmao)7+ i2flh pv7a

  What is not a function of the myelin sheath?

Explain how the resting pote /8bl+1+atkrxggmu 7f ntial is maintained in a neuron.

The diagram represen0;jmfwd b;7e mab d7+)8kc 6izcyf(w lts a synaptic cleft between two neurons in an insect's nervous systemdlci 7mek8fmbyz bjdwfa;;c67 +)(w 0 .



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 structure of a typical neuron.zu.drf)o3ro+
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(nttr6vzdq. l: y(qj7 used 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 mellifera carnica) were treated with non-lethal doses of two neonicotinoids, Imidacloprid anqy6 jd(n7l.ttv :z r(qd 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 kt24g4q vu 1di c.gmx8ksp: :61htmtmover time during an action potential. Which letter represents the segment of the actitvct :uq.4x4m :d1ki1km 6gm8 gh2spt on potential when voltage-gated sodium channels are open and voltage-gated potassium channels are closed?

  Which two features are more abundant per unit length in a non-mbe+y kb 09o-;5m,bmn hs alim5v2fy-yyelinated neuron than in a eam9 5mfby ,bshil+ybmno ;-y0-2k5vmyelinated neuron?

  Which of the following is a/are co c37 rduqu.8;;y imxzp.nv bl,rrect description(s) of the relative speed impulses are conducted ac3lr8xypvn; . ui 7;muq,z bd.t?
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 occ7bc.jv,*v dfcrh xprd- dxq+ bu8z*-by.* /hxurs in the membranes of neurons during a stage of the action po *-**qb cr.y8.zvjhx x rvb+,-hdbd7cxd u/fptential. What process does the diagram depict?

  The image shows neurons that are found in dog brains. What does letter X i(p 6ljhnzu;b7n4k;m0e hffu8ndicate?ble; 0hf;zj 8mu67nuf n4pk( h

  The diagram shows two neurons of equal length and diameter. W06lo.ia -l15 higg0hy;mnusw hich neuron will transfer an eloa0u-mii glh; gn5 wsy.6 lh01ectrical impulse faster?

  Which triggers the releas4q*v klb9.iew 8fcr /58xe hpde of neurotransmitters from the presynaptic membrane?

  Which mode of transport do neurotransmitters use to travelf;cn5surgls7x;, 9ie across a synapse?

  Which statement explains why a nervcxl+r,00kr vom2 -vdje impulse is electrical?

1.Explain why a resting potential is whkhz/fj0vh5a xbwez: ciu 1d: ne1ks4;a 362negative.
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.