What happens if the th3q zb p59(o5,zjqymg b+fsh f zw48tl dh;t2e3reshold potential is not reached ?

  At what membrane potential do voltage-gatedmsji a,5k fhu2;4k sn4 sodium channels open?

  The diagram shows a c/ (krrd7ir; +p)ocw qneuron.
Which arrow indicates a dendrite?

  How do neonicotinoid pesticides workw s4qj6c9la 8oz+mc4g?

  The diagram shows an action potential. 1w3kk8;6lm-v m giica

What is happening at point X?

  Which is the correct definition of saltatory condj zonso9z7 ds uz4*z *jj7f1;zuction?

Neuronal cells have special membrane prop :ygun6y4 )y :y0ir3e9 hatyzoerties that allow their axons to propagate action potential from one cell to another. The diagram b:)4yt heia g0yyu6y: o9znyr3elow 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 memb6 t0xiln /r(gcrane?
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 n qeg v5rk7 ibw0zf2:l8lf dqltk )7t-/euron’s resting potential?

  What is not a function of the myelin sheath?

Explain how the resting potential is maintained in a neuron*3d igb7s0x /+ mpqlna pq9w408zkvdn.

The diagram represents a synaptic cleft between two aq 7kcb2,n rc tb3k-f(otdv-5 neurons in an insect's nervou-7k(n 2tc ,b5f3- bqc oktvdras 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 neurvr gu r,9iu mv71o:ex+on.
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. Howdk9izpvj (b1- s/jjz 5ever, there are concerns about their effect on honey bees and other pollinating insects. The table below shows the resul-/5bj zd1jz p9kisv( jts 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 action potential. Wh j ; e9fcrv7jv94bmu/h :cr1qbich letter represents the h:qv; e9vr jm7cjb4 b1f9 u/rcsegment 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 aqba z6 8b u79c2lkjtu0 non-myelinated neuron than in a myelinated neuronu ku9bjcq2z6a80 l bt7?

  Which of the following is a/are correct description(s) of the re2e+kjn*vd5xe r d0p o.lative speed impulses are condu*e nrkeo5.0jd+2v x dpcted 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 occursbha ex30hh.1 .g4h/v./h l pkdlf ,pnx in the membranes of neurons during a stage of the action potential. What process does the diagram dea.hhgpl/ /p1x3dhv x0,n. h. l4hb ekfpict?

  The image shows neurons that are fo 5b3mn*a dz/xb v++uddund in dog brains. What does letter X indicate? /*anu3+bmvdxd d z+b5

  The diagram shows two neurons of eqa6j 8-fozgexq y7a0 we1f )6mgual length and diameter. Which neuron will transfer an electrical impulse faster?fmw6azq feg 8ej7x1ga -)0y6 o

  Which triggers the release o 51f)/ h7mnfmqgcxfqs(fpuo0yk,5 5h f neurotransmitters from the presynaptic membrane?

  Which mode of transport do ne abcyw8f7lm9 :urotransmitters use to travel across a synapse?

  Which statement explains why a nerve imphg 5+ k8noc;yfulse is electrical?

1.Explain why a resting potential is ) mf* umyxp2pa :xu7jhn79s. anegative.
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.