What happens if the threshold potenti961lff3 2uf mxj,ztehal is not reached ?

  At what membrane potential do vo i jjk ) +kn4,*j:0tgorgs)txwltage-gated sodium channels open?

  The diagram shows a mte b-ieyo1 67fsp7p(,v sibv5s; /dnneuron.
Which arrow indicates a dendrite?

  How do neonicotinoid pesticides wor; 6b,a6my amx 5qpgzi7k?

  The diagram shows an action potent8 9p5hr30na,bd cdtxu8ax zk 6ial.

What is happening at point X?

  Which is the correct definition of saltatorymivxl :s6)yq ( conduction?

Neuronal cells have special membrane proper 7qvwpz((yu ma ov68c j2qq/;hties that allow their axons to propagate action potential from one cm 8(( o hjvavy/;qquwpczq762 ell 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 1e4, nl rztu a-,bcr0sof 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 as*h c7xfim:9 3kotv/,fztqu + u jxw;/ neuron’s resting potential?

  What is not a function of the myelin sheath?

Explain how the resting potential is mi*zs4-2d(jop8 kso;, *cwcefpua /oraintained in a neuron.

The diagram represents a synapticz5 v kcaw-10tc cleft between two neurons in an insect's nervous c5tcw - 0z1vaksystem.



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 neuroov b* syx3su)we; fnv.vzl1((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 t12* r9h0zk n qwec(urqhat are widely used as pesticides. However, there are concerns abrcz(hquk9 1 e0* q2nrwout 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 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 vo ybwvk.51ma(cp3s(f m ltage over time during an action potential. Which letter represents the segment of the action potential when voltage-gated sodium channels are open and voltage-gatek1(wafpv c mb(ym 35.sd potassium channels are closed?

  Which two features are more abundant per unit length in a nobe n* ,gfu5d5b9 9tbann-myelinated neuron than inun 5a5tge9*bdb, 9 nbf a myelinated neuron?

  Which of the followiniw f;*jw0f 9m5ho6m kyg is a/are correct description(s) of the relative speed impulses are o jfh;m wwfm059k*y6i conducted 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 proce4v mmyl o-w rt0wp3:b9m3i 1abss that occurs in the membranes of neurons during a stag avim tbwwlp9m:301r4b moy -3e of the action potential. What process does the diagram depict?

  The image shows neurons that are found in dog 6qzjq54: cezp 9lruoe3ry) i3brains. What does letter X indicatejezr lczuyie349o5qp3:r)6 q?

  The diagram shows two n o(5+ppgp4nb,zbil 9l eurons of equal length and diameter. Which neuron will transfer an electrical impuli,lb4g5bz(lpo p n9p+se faster?

  Which triggers the release of neurothn+tv ozci 2zy2t98 d9axrj4 0q-px5u ransmitters from the presynaptic membrane?

  Which mode of transport do neurotransmitters use to vql /bk,8ykk vf5h8 9(ukb /hvtravel across a synapse?

  Which statement explains wou:c(7 k 8nl8aaf5qmv hy a nerve impulse is electrical?

1.Explain why a resting poiw* 321n3q7a qah 4jbiw/vlj ctential 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.