What happens if the -ktvzm9yr* 2j7 wddj:threshold potential is not reached ?

  At what membrane potential do voltage-gated sodiut bc 0x4fkvzh:qcf -59m channels open?

  The diagram shows a neuron.l. y8ypi:,dr lv7 6xrbpc)wn5
Which arrow indicates a dendrite?

  How do neonicotinoidm8ofy*/vrb6xrp .x9 rwh 7sjj9/6n sx pesticides work?

  The diagram shows an action potn3emv+gee: x-hph* 7bential.

What is happening at point X?

  Which is the correct definijmqm s/d y9) k rhxzp22s3u 8etfrl074tion of saltatory conduction?

Neuronal cells have special membrane propej- gyda6.kl3zrties that allow their axons to propagate action potential from one cell to another. The diagram below shows a portion of an axona 6kz. jlya-g3dl 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 presym b ).x/tjo3dwnaptic 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 neu.igv.*sba /ng 9lumo1ivk2n3 ron’s resting potential?

  What is not a function of the myelin sheath?

Explain how the resting potential is maintained inrpcbp0+ v h/tp /zvv8( a neuron.

The diagram represents a synaptic cgv)6z3*8vybkvln7)vfi / ubqleft between two neurons in an insect's nervous sysiv8l/)k37vv g)vz fqy bu6 *bntem.



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 af- 6je mr xp:iws 6joc/j4jdgcl0y:9y i;d8) d 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 pestic:w:no/e5f95ihjo.-ytxe ti; :is;hpwd(c nvides. 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) s;w/:o .y n w9v(:ei;epf-ixin j5dh tt:hco5were 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 during an x,,q neoqx( 6rg 6x0pvaction potential. Which letter representq,vn6e6 r(0gxq pxo x,s the segment of the action 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-myey,ghy7 -l)yuhlinated neuron than in a )yy ulh yh7g,-myelinated neuron?

  Which of the following is a/are correct description(s) 3vnu nhs3ovtxk+z+ sqv0 53n)of the relative speed impulses are conductesn3nvos +tu0n5k q x3vv3hz +)d 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 neuron84qd5dqv2lu; yqnom ;hfus.9s during a stage of the action potential. What process does the diagram ;.; m 89qy4quu nsf5qlv oh2dddepict?

  The image shows neurons that are found in dog brains. Wh(ug3h0v h))qk m+mslu at does letter X indicateh sg qmk(3lu )hv)+0um?

  The diagram shows two neurons of equal length and diameter. Which neuron wilr.ogz . 74wrjr:;z8zaq mia*n l transfer an electrical impuaz .rr 4:.j8qg;az7on *wz rimlse faster?

  Which triggers the release of neurotransmitters from the presynapticnzrc a 3mwvlk+a(9: ,gu .bh-d membrane?

  Which mode of transport do neurotransmitters use t3tny: (ugfr/oo travel across a synapse?

  Which statement explains why a e(zb+; vektw*g4f jmv)+gz/enerve impulse is electrical?

1.Explain why a restinoy ,llss y l2cj.u--,og 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.