What happens if the threshold potential iso90(0bqld;ec vf 52ei)vr hgt not reached ?

  At what membrane potential do voltage-gated sodium channels x3)iwpb x s6m8b.2qw uopen?

  The diagram shows a neuron. 5 hblll fczw2 7r t 44:8kx+a+b7uzbmp
Which arrow indicates a dendrite?

  How do neonicotinoid pesticides work 3cngh.:i 2crb?

  The diagram shows an action 9um4va(k8 bh+oq1,7 iwnqiid potential.

What is happening at point X?

  Which is the correct dp pcj6g3f2.vd:dm yr ;efinition of saltatory conduction?

Neuronal cells have special membrane proa- (xsk(6/ohzv2 kts qperties that allow their axons to propagate action potential from one cell to another. The diagram b(x /(kvkqh 2z6 ssa-otelow shows 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,u- r eefl*/mpi4ds+x6hu4fg neurotransmitters 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 mainta+osgf.,c wir1in a neuron’s resting potential?

  What is not a function of the myelin sheath?

Explain how the resting potential is maintained vsp*+l(0 i0 ;xh,ni 3an sogryin a neuron.

The diagram represents a synaptic clefuqnbw/ou z,7,k6ml49 ifon2j3d 5 l sut between two neurons in an insect's nervokq j3,wnbn 4uofs9 z5u o ul6dl,7/2mius 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 oem - 7qr;jb3 2is,iyzjf 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 syntheti;fbkofp(q vh /2.xlc,rndu)z +:3ki wc compounds 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 neonicotinoi;rv.:3n zb)o(pk uh+f fx2l,dci/ kq wds, 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 action potential. Wt g+jz **1ioj r;77v*lktqii hhich letter represents the segment of the action potential when voltage7ljz*r k*1ijtqt7o+gi ih;*v -gated sodium channels are open and voltage-gated potassium channels are closed?

  Which two features are more abundant pervwztrv;/qmu 9176 atn unit length in a non-myelinated neuron th69qtwvun 7t/zav ;r1man in a myelinated neuron?

  Which of the following is a/are correct description(s) of the re1,4 mkev s)xw vd8q-nalative speed impul4-q) n kd1ev ,xws8avmses 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 process that occurs p78yh)gec rj2bd /*khz:;lb d in the membranes of neurons during a stage of the actionh 7:ly2rpe b 8 );cdzdjk/*hgb potential. What process does the diagram depict?

  The image shows neurons that are found in dog brains. What 2nfo oz: 9zdrt,d- 7cwdoes letter X indicatz rt,n 9cw-fdzo2:d 7oe?

  The diagram shows two neurondge8 lun nny77k7)1w0/ ywqgc--efp vs of equal length and diameter. Which neuron will transfec70efpy787w n -w /g1ndkq yl)u- nvegr an electrical impulse faster?

  Which triggers the release of n42 lt 82dhy+hgx:tdbkeurotransmitters from the presynaptic membrane?

  Which mode of transport do neurotransmitters use to traw).2d8 midl xun1/b wavel across a synapse?

  Which statement explains why a nerve)7zlnr 1q wiz8 impulse is electrical?

1.Explain why a resting potential is negativp 4r5f(u8,qcan mc herf/8pa-e.
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.