What happens if the threshold potential is not reached +s70ybwo,jnsb7 p 6eh ?

  At what membrane potential do voltage-gated s ,hdq,70h81 e4dtsy1 pau xqthodium channels open?

  The diagram shows a neura;w0.ptc fa u :b4lq1aon.
Which arrow indicates a dendrite?

  How do neonicotinoid pesticides p+ucmzs j4i;* 7hhfj*work?

  The diagram shows an action hlrbh/; ( og*)isfj)w--mwlv potential.

What is happening at point X?

  Which is the correct definition of sa*+5 gecd1wd:mt nzi( rltatory conduction?

Neuronal cells have special membrane properties that allow their axons to propag)uxi1it7 suy5r (9jo wate action po 9i)wt1uy xsju 7i5r(otential from one cell to another. 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 pr2y6e 1isaxqiy 4c n+0+jba )qqesynaptic 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 neuron’ss kd24hu/g p(u,)tiks;dh c fh6f* lm9 resting potential?

  What is not a function of the myelin sheath?

Explain how the resting ygy 1a..*m1vpzxsi8 z potential is maintained in a neuron.

The diagram represents a synaptic cleft between two neurons in an in ,8fwd(*k jhe0qqqig9sect's nervoiewqq kg,0j8f(9d *hqus 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 neur v f,h9orwsi0vx*n ;f4 be* da,n9lko2on.
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. Hobrmcdp:w * 30awever, 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 ibm* d3 wpa0cr:nstinct (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 duringrimaei4iy83 0 an action potential. Which letter represents the segment of the action 4ii3i0 r ayme8potential when voltage-gated sodium channels are open and voltage-gated potassium channels are closed?

  Which two features are more abundant per unit length in a5e8muoamgx / + non-myelinated neuron than in a myelina+5 u/o eamxg8mted neuron?

  Which of the following is a/are correct description(s) oaejd mf8u6kru0 ze2*lp, i( tf,m59ubf the relative speed impulses are conducted ail8b5,a 6te j(2m9p *kdefuuzm ur0f,t?
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 during a stadipx tboul,r*l9:w+5l2 a (ccge of the action potential. What process does tb c,olp(9ulca+r2xwid *t:5lhe diagram depict?

  The image shows neurons p/r*pv(z: xsqthat are found in dog brains. What does letter X indicatvp/s pr(*z: xqe?

  The diagram shows two neurons of equal length and diameter. Which neuron will trcj7 *ezk7 5ry9wh+ys yansfer any9w5k+rjey7 *7zs chy electrical impulse faster?

  Which triggers the release of neurotransmitters from thehp p8ah4ly7 u0xldob:ia:5 + i presynaptic membrane?

  Which mode of transport do neurotransmitters use to travel across a synapsrr,bfgum)b1xg c( 5z16l.ic me?

  Which statement explains why a nerve impulse is electr(3nlf3 d0 p44oisij g;k ccle 9;(ndxgical?

1.Explain why a resting potential is *fc 4*d,spov +zkm c3go4c3zg 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.