What happens if the threshold potential is not reached ?lszu*tk ga ym: ,*fq574lgkt )

  At what membrane potential do voltage-g05o dbh:nvygi nn740n ated sodium channels open?

  The diagram shows a neuro)tkhxu3m u31m z/8vd on.
Which arrow indicates a dendrite?

  How do neonicotinoid p5cxhy5yw9 l;x;pqc8x+i x(s o *zk +miesticides work?

  The diagram shows anf*0dow-vx rya)w(:v qfbt9x * action potential.

What is happening at point X?

  Which is the correctb 03skb2) qwtc definition of saltatory conduction?

Neuronal cells have special membrane properties that allowmoyq ):u2 uxv8 their axons to propagate action potential from one cell to anoq:mv8xyu 2o )uther. The diagram below 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 neurotransmitters at the presynaptic membra gmo3u2-i)yd jne?
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’s resting poten yyh9ah *:vj0 ev0xd(ktial?

  What is not a function of the myelin sheath?

Explain how the resting4uiodytux85 o q +4s7f potential is maintained in a neuron.

The diagram represents a synapti)4h .;nanrvmkc cleft between two neurons in an insect's nervous4khm )n;ar.vn 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 of a typical neudhf63f19bjdsop3 c3u ron.
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 use 3psmhe 3xfwe 6blw+:4e(xrc 5d as pesticides. However, there are concerns about their effect on honey bees and other pollinatwew xer4f6:+3( 35pslb cmxehing 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 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 actionf0cmq 3hy5 4h;mpl b4a sh2;yo potential. Which letter represents the se5;hlyqcba o0p4fmmh32 ;ys 4hgment 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+:p7 w aiqo3mu4 hab,j unit length in a non-myelinated neuron than in amb 4q7+j,wah3pa oi:u myelinated neuron?

  Which of the following is yc/b q+j459kr llg5owa/are correct description(s) of the relative speed impulses are conducted ll9ko+g/5qcyb 54jr wat?
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 i g rr;gtz8 6qll7nrdlz o*1kkp/ g7-w8 q9hoq+n the membranes of neurons during a stage of the action potential. What process does the diagqpdln 7wh;g8q1ro 8okz l*r9gqkrl7 /6tzg+ -ram depict?

  The image shows neurons that are q-m jo4uzmx clp-6.q/found in dog brains. What does letter X indicatzlj- q/qxp o .c6um-4me?

  The diagram shows two neurons of equal length a23c) vt*kh3 ir(njc oand diameter. Which neuron will transfer an electrical impuj )2ktn3 3acvch(r*io lse faster?

  Which triggers the release of neurotransmitters from the 8uq1 ;)retzlbsyr5rto :+ea/ presynaptic membrane?

  Which mode of transport do neurotransmitters use to trav(++em yi gi2w2 tocvpay4- +tnel across a synapse?

  Which statement explains why a nerve impulse is ey izl8w6k4 9n+kzpag;lectrical?

1.Explain why a resting potential is nega4pxnuk d:uer 83av88s (yo4rctive.
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.