What happens if the threshol.wpfvpm9t q)*se u0w9 d potential is not reached ?

  At what membrane potential do voltage-gated sodium channels open?wyv7o-4 5fjcg

  The diagram shows a neurlqmg0lwk9p 1v 9:r6ou;yenq , on.
Which arrow indicates a dendrite?

  How do neonicotinoidml*5afq zm6ea m y*2e( pesticides work?

  The diagram shows an action potenti y mp7q :3mokll3biq8/al.

What is happening at point X?

  Which is the correct definition of saltatory conductio jz+ de,6k c69muc up4kb nz,pa1p0gy)n?

Neuronal cells have special membrane properties that allow their.ff/ w c:sc55gto mn k.f:7hwjvg0, jj axons to propagate action potential from one cell to another. The diagram below shows a portion of an axonal plasma menf j75hmfcg:0wvs:tofck,j 5/ jg.w .mbrane.


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 presynaptic m udhz-;1rp+fr/u6b xhdo 9j/fembrane?
I. Depolarisation of the postsynaptic membrane
II. Depolarisation of the presynaptic membrane
III. The diffusion of calcium ions

  What are the main falf5zm wpp+una( -+ 0nfctors that maintain a neuron’s resting potential?

  What is not a function of the myelin sheath?

Explain how the restinqr5 2r-a fek46evo+;ig1o6 n p+ xonujg potential is maintained in a neuron.

The diagram represents a synaptic cleft between two neurons in a 1e4o b3twq+57msvit:dy ,jrqn insect's nervous vmt314dei,5o +rt7q:wjysb qsystem.



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 n/ bp:)t:kfgj 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 compoundecj 9;ki26ygfuzk slbb(b; . +s that are widely 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 and Clothianidin, and the effect it had on their homing instinct (ability to fly back to thef .b(;6bu2j9g i;kyl c skb+zeir 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 dumuti3*bb/ s: yring an action potential. Which letter represents the segment of the action potential wheny3s /t :u*bbmi 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-myelinated neuro .l9(o;vt9gfr0kf yqk:y gfv (n than inqfo;vt(0gv9r9:. k ygfly( fk a myelinated neuron?

  Which of the following is a/are correct description(s) o4ejl z 9vx /boo7wj06gf the relative speed impulses are conducted ato/z670gj 4bo9v eljwx ?
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 neurons dury (23 *xo: wt knp+r( :dn2clgnlbrvcuoy,7 o6ing a stage of (76u y:(2gl, nldcnor2vxpntr w bo:co+k3*ythe action potential. What process does the diagram depict?

  The image shows neurons that are found ipt9rtzsr tser108d*s3jg v4) n dog brains. What does letter X indicat pg89 04t tssrt*eds)rzjv13re?

  The diagram shows two neuronsww1n:daxasa7+s+3) jy w 7jm r of equal length and diameter. Which neuron will transfer an electrical impas3 wja7 j:aw)w7+ s d1nx+rymulse faster?

  Which triggers the release of neurotransmitters from the ypr go .7xpa9ogy1c 95presynaptic membrane?

  Which mode of transport do neurotransmitters use to travel a7 t1ebf 1xpl:ib fh:e)cross a synapse?

  Which statement explainevf. brxkk xvobp yg)6f h)- z.e576f+s why a nerve impulse is electrical?

1.Explain why a resting pot-fw .ht r63 xrtvg/qr 30+gq pl9o4kzcential 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.