What happens if the thresholdo6aw:5ey pf lw2y.:xv potential is not reached ?

  At what membrane potentiacp+3*4r le+y18bhnaf j,a nk,rs nr. il do voltage-gated sodium channels open?

  The diagram shows a ;l vee ruchne+od0gd3 - o/n).neuron.
Which arrow indicates a dendrite?

  How do neonicotinoid p/ qsvk on// 1qsf/x:ess nrn:,esticides work?

  The diagram shows an i-c3 3av,9ysl7 zu vdaaction potential.

What is happening at point X?

  Which is the correct definition of saltatory condm*xjub(c5g pop1 ,dx2b nyl0+uction?

Neuronal cells have special membrane properties that allo 3nma;hu2uwf* zj+1+m/hjofi hea .3yw their axons to propagate action potential from one cell to another. The diagram below shows a .au 32*if h+h umejym+f a1zo;h/3nj wportion 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 neurotransmitt offrf+;jw a k0+hmcgc0y5 1,bers 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 maintain a i pw2;,wc q8pz8(lsbac2j,i tneuron’s resting potential?

  What is not a function of the myelin sheath?

Explain how the resting potentiawd gy,wy /g u+i6( nh+-+b k-mpjd8xlx6o0yxfl is maintained in a neuron.

The diagram represents a synaptic cleftjvstvyd2u,b u36 9jz)i-9zk5 cfe ou2 k:hy0 u between two neurons in an insect's nervous sysuj5c 6ik vuf)2 t9z0 z:huo9ju d v3s2y,ek-bytem.



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 a n. hbul,61y eetypical 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 pesticidel2j)m/6n1 s1l+u ii) wvgkuje s. 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 +2)m g1/u j) 1kuwelinijl6 svtreated 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 voltage8uh :pflq 7n-uak+7v x over time during an action potential. Which letter represents the segk ulx 87n+7ahq- fp:uvment 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-myelinated neurong;5og dq uif4b( 5vppzr;y)f: than in a myelinaq u5 bd :f;zr);p54p vg(gfiyoted neuron?

  Which of the following is a/are correct description(s) of the relatlqixlr; x:h/sq-kjf 5pm8j) b;b )4jt ive speed impulses are l m;jsj4x)qtqi8bkrf5p)h j;x/- l :bconducted 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 -b gtf4j ap52k/zkcs:in the membranes of neurons during a stage of the action potential. What process does the diagram depika 5jgfz tb k/p:cs4-2ct?

  The image shows neurons that are found in1zd)8 x2vb r; dcz*ibk dog brains. What does letter X indicat;kzvx12* rdbzbd )c i8e?

  The diagram shows two neurons of equal length and diameter. W344 q+2 tdwytctj d;w9 uzan7vhich neuron will transfer an electrical impulse fa7d9wttywj zu a d4v4+3c; tnq2ster?

  Which triggers the release of neurotransmitters from the presynaptic membranenz(t f,4n1d gnfvnp ,(?

  Which mode of transport do neurotransmitters use to ) fbye1,tq /rstravel across a synapse?

  Which statement explains why a nerve impur1l2d bfwul,8 lse is electrical?

1.Explain why a rest7bitx r(cfd6 5ing 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.