What happens if the threshold potentl oewt 6s 8ub0un13:8ax rssy8ial is not reached ?

  At what membrane potential)*5k:vf gtg mf do voltage-gated sodium channels open?

  The diagram shows a neuron :am2o en)8.;i lblgl.lkux7u.
Which arrow indicates a dendrite?

  How do neonicotinoid pestici)btew*5uv v 8fmt(k(5 n bnml2des work?

  The diagram shows an actio+vs)5,f 6g g-cbqv zo) zed2aon potential.

What is happening at point X?

  Which is the correct definition of saltatory conducti)3ret 5o.bplzon?

Neuronal cells have special membseyxef -1k0bu m4pndar );*q*rane properties that allow their axons to propagate action potential from one cell to another. The diagram below shows a portion of anu4-*f*1 k ybrq) ;emesa pxd0n 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 m gv 1vzbn0h54 mh5q1qpresynaptic 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 potenti jze(z;,8ilaxal?

  What is not a function of the myelin sheath?

Explain how the resting potential is maintained in 6b/r:xj /lsl na neuron.

The diagram represents 8/-kd ,ti*z-sx vtonia synaptic cleft between two neurons in an insect's nervous sysk8ntvt/- sio- zi,*dxtem.



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 s(9*rxzc8ierld(/ 0eoa n 7oaltructure 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 used as fhax: l117s r3d/ +cz8a-2suo wd jr.qcqs+c upesticides. However, there are concerns about their effect ons r2 3+r1slws hq/zaa1 -7ujdu cd8+q xf:.occ 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 voltage over time duregvsegm0 1;jw 0i gl9h;+ur6king an action potential. Which letter represents the segment of the action potential when voltage-gated sodihv;gig ; 0109eumjekl ws6g +rum channels are open and voltage-gated potassium channels are closed?

  Which two features are moz udgde.4) 305uhvh f qv1t1isre abundant per unit length in a non-myelinated neuron than in a myelina4z 3 51 vtuevdg.h s0qh1uf)dited neuron?

  Which of the following is a/are correct description(s) of the relatik b0o cif4 eg*y7mijln*7.e*w+lvaj /ve speed impulses are cj. n/i wef0la+lm7g7b4iye ok c*j*v *onducted 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 ixq1(wdh1i j kyh5qws34hi2:f7ml l ;bn the membranes of neurons during a stage of the act xsk;2:yjqq m5 hwihiw1hl3d14(b l7 fion potential. What process does the diagram depict?

  The image shows neurons that are found ioh xjrwb1(*g2jzhlr4 hc((o8/p ;giy n dog brains. What does letter X indicate? 8jwxrryp hi/bolgg ;(1 (*4 hj2 ozch(

  The diagram shows two neurons of equal length and diamiu- hl9lxd 0d u yeza88,//rtb69p kfceter. Which neuron will transfer an electrical impulc9 zdulhtf9d/lkr yb0/6eau8,i8 p-x se faster?

  Which triggers the releasevx*wy a/f+bo) of neurotransmitters from the presynaptic membrane?

  Which mode of transport doo 7etcus -a(0v neurotransmitters use to travel across a synapse?

  Which statement explains why a nerve impulse is elexxx(55gn3 :b ji eb::d l8nshoctrical?

1.Explain why a resting po*3h fec4nri/p3 jjmleh0 uzrh --;c/stential 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.