What happens if the threshold potential st ba/l43z. ihis not reached ?

  At what membrane potential do voltage-gatxi - 9intl50da:n hqhd-0-xxfed sodium channels open?

  The diagram shows a n.3cwn;plv4lx euron.
Which arrow indicates a dendrite?

  How do neonicotinoid pu lyxcyx80hoj5a,3t :esticides work?

  The diagram shows an action ponzrn; ba*ds4+ tential.

What is happening at point X?

  Which is the correct definition of saltq 5derpmujs5sn(27f) atory conduction?

Neuronal cells have spe k-gd1q:momc. cial membrane properties that allow their axons to propagate action potential from one cell to another. The diagram below shows a portion of an axonal plasma mem -mgmo: dqkc.1brane.


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 pres+truor mg6z 5g8o;k4n u0b /ciynaptic 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’smr n-z ra05+mt resting potential?

  What is not a function of the myelin sheath?

Explain how the resting potential is maintaine3sfn a w5geo )jh(fp 9zkdm-91d in a neuron.

The diagram represents a synaptic . q2g1irx cv(zy)d+fh4eu. tolt4sjb. vg4 3pcleft between two neurons in an insect's nervof.jl4 (vy h4e4) xc.3qrb d1 tt2zgvs.p ogui+us system.



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)pqbg* g,xg se/* ;)3lmj avep 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 pesticides.lrdbxcy b084h t4517dum q/xa 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 a81ra0xm 4dx d4 uycblh5 b7tq/nd 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 act63es pvz6-mju+p r3gz55xpafion potential. Which letter represents the segment of the action potential when voltage-gated sodium channels are op-e jfz5+3ppmx6pu3ga5r zs v6en and voltage-gated potassium channels are closed?

  Which two features are wopt ;mue c6 o-cf290nykd 8:hmore abundant per unit length in a non-myelinated neuron than i o6ke 2dcp8;0mnyc o-uf h:t9wn a myelinated neuron?

  Which of the following is a/are utk giw-t/35u8qvvy3q- zhy3x (xcm: correct description(s) of the relative speed impulsesx5wiqxc v:3um ykh (-z3/ yv3u8qt-tg 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 kk 8 1p5daopwek0.3o sprocess that occurs in the membranes of neurons during a stage of the action potential. What process dp 5es ak.81k 0dwp3okooes the diagram depict?

  The image shows neurons that are found .j:;h+( sil- rboamkh in dog brains. What does letter X indicate k a:. ihjo(+lmh-s;rb?

  The diagram shows two neurons of eqj o4 x1:us bv):zezwj6ual length and diameter. Which neuron will transfer an electrical impulse fae4:jxswo)b61uv jz : zster?

  Which triggers the release of neurotransmitters from the w.0h3jt(vmkfn cl fgj s*) c2(presynaptic membrane?

  Which mode of transport do neurotransmittn 7. ca(rksxgdtqss* i9s-e2.ers use to travel across a synapse?

  Which statement explains why a nerve impulse is el83wy xu::kqgv, d9zo oectrical?

1.Explain why a resting potential is negativerg9j7*3i l6f w /yqskj.
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.