What happens if the threshold 8b7p uc;l.tu ypotential is not reached ?

  At what membrane potential do voltage-gated sodium channelsqs t zxpe:0v/. open?

  The diagram shows a neuron.yui+g),cs u(f
Which arrow indicates a dendrite?

  How do neonicotinoid pn;pjx8 5l,a caesticides work?

  The diagram shows an action potential.6y;3 yustm (dach6 (+.jebwna

What is happening at point X?

  Which is the correct definition of saltatory conductionj:vn;t+r k9ogljw n 3/?

Neuronal cells have special membrane properties that ,5fmd q95uf ig zt7yo5et+hy2allow their axons to propagate action potential from one cell to anotheuhi,mg z5+ytdeq52f579 o ytfr. 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 exocko014p 5x ,*tt7 ykau 9gffybsytosis of 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 maintain a neuron’s resting potentialqqf.il, x (,7yuojvd 90h9oxo?

  What is not a function of the myelin sheath?

Explain how the resting potential is m(z kxw9.in i5xl(lu(b;- q/t7sue kkpaintained in a neuron.

The diagram represents a synapbabd(ull 3+w;tic cleft between two neurons in an insect's nervous system;(3+ba bdull w.



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 neurow6pf(wdo fg -,r/ px1b0 h+xu eaj,ahrt 2w0n-n.
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 pesticide5i.p-uw ep m0ntw2gn65u 9ccws. However, there are concerns about their effect on honey bees and other pollinating insects. The tabp0-e ui9w5w2unwc tc np6g5.mle 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 acmrd*q (s*n3 *qm wq1yation potential. Which letter represents the segment of the action potential when voltagwr a mqdq(3y*mq*n 1s*e-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 ne r(g4pru7x 3gnuron than in a myelinated neurorp4nxu3(7gr gn?

  Which of the following is awa d6zasa 9 (83l-ngum/are correct description(s) of the relative speed impulses are conw8am zga39l(sda6 nu -ducted 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 ine fbp*:8g8d( u8 sol-omdai6. 8xvvrh the membranes of neurons during a stage of the action potential. What process does the diagram depict?d6fplvmb8 8*rgd a-v8se.u o:h(x i o8

  The image shows neurons that are found in dog brains. What does w bz :7tjgw;w/letter X indicate?wwbj/t7;zwg :

  The diagram shows twp5x8bm9 5kttb4d) j5zsc h dn(o neurons of equal length and diameter. Which neuron will transfer an electrical impulse faster? d9jp 5 5 ztc4x8 nsd5b)bkt(hm

  Which triggers the release of neurotransmitters from the presynaptic 9j 9odyw 5d0pemembrane?

  Which mode of transport do neurotransmitters us4w/r3iwlw a9qf b 7pb0e to travel across a synapse?

  Which statement explains why a nerve impulse d gb0 nq2vs:u2s su:7yis electrical?

1.Explain why a resting potentialkdcub+,/ q f s9y,o/oj 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.