What happens if the thresholgtw0 qqntx2 :wzp)g4 9d potential is not reached ?

  At what membrane potential do voltage-gated sodium channels ((k blzpl4 7vzopen?

  The diagram shows a neuron.q 3q-o/*la(jdzw, qh v
Which arrow indicates a dendrite?

  How do neonicotinoid n-hsu 7y80lj dz.bgu;pesticides work?

  The diagram shows an action p,wrk4 j m1fm0krp, ,f6 leiyn7otential.

What is happening at point X?

  Which is the correct definition of salad2g pa / (gx-,jv.tgltatory conduction?

Neuronal cells have special membrane properties tfpd- g3bxs p4r0/ g*cjhat allow their axons to propagate action potential from one cell to another. The diagram below shows a portig 0g c*3f4xr-/ bspjpdon 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 neu 8:e1vjz h1 -tce*8iv gpqd7u0oif4 qmrotransmitters 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 restingx-o23hem1 m o3s tay(j7 a9otv potential?

  What is not a function of the myelin sheath?

Explain how the resting potential is maintainuzoglz +6rz9jzx6ba fy7sh-k0 f70 6eed in a neuron.

The diagram represents a zfj-7icmhk d:of 7j 3x:dc xg+6z.hc/synaptic cleft between two neurons in an insect's nervous systemh zk/dj3 cxzxfjc: 77h if-g:d.m o6c+.



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 neuron igw(2hc)qt2hc0ka5 v .
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. Howvc +xaog)b:v t:: bfn2dwjb7 3ever, 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, an)t:3 v:dwjva f+b 2 gb7ocbn:xd 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 t9 )vdmbvup.1an action potential. Which letter represents the segment of the action potential when voltage-gated sodium channels are open and voltage-gated pota.tud1pv vb)9mssium channels are closed?

  Which two features are more abundant per unit length iv: sij;g wmfb)n2/f8 ;fb ;zuan a non-myelinated neuron than in a myelin;/wfjz;fb:8;2 us )nmaifvg bated neuron?

  Which of the following is a/are correct description(s) of the relative speed+(n/jl veams/ impulses are comna l/j+(s e/vnducted 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 in thep5d)d-2lw+vkc bz7ehby,l2r2gb kg u 9d u /4m membranes of neurons during a stage of the action potential. What pr97)5r4 uke+hl- dczl vbbpbu/wg2yk22ddg,m ocess does the diagram depict?

  The image shows neurons that are;xxn3(ab cfk98 9ooo9fsi )mi found in dog brains. What does letter X indicateo) oi 9fimnxx;foc s9a8(3k b9?

  The diagram shows two neurons of equal length and dianph o;rgl6 7gwlj 1(kl6l;f*vmeter. Which neuron will transfer an electri 7nvr;w(g6jkll1h 6fglpl; o* cal impulse faster?

  Which triggers the release of neurotransmitters from the presynaptic membra 7ih*y -fj(i1vq yfj64ragne(ne?

  Which mode of transport do neurotransmitters use to travelspm2et c4g3l . across a synapse?

  Which statement explains why a nerve imix 2/u vail7v8:dagpxi)9y3x0z;u pppulse is electrical?

1.Explain why a resting 6bnrz n(*h( .tkibhr (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.