What happens if the threshold potentii; x.u l4nysqg) tx*2bal is not reached ?

  At what membrane potential do voltage-gated sodiumkp:u7 qv e (kcbl2ds;/6gtl h5 channels open?

  The diagram shows a neuron. ctuugxjnp5+ivl; *0 9
Which arrow indicates a dendrite?

  How do neonicotinoid pesticides woawe.f8orz 7 lyqbabv 8h-qq+ ma;4,n )rk?

  The diagram shows an action potentp 4hdq :x+4 qd,m2zuxoial.

What is happening at point X?

  Which is the correct definition of salt 1vo)g ; plvxxsdg76o5atory conduction?

Neuronal cells have special membrhbt3*yp;. 3hd zeig n)ane properties that allow their axons to propagate i 3yd)p*hg3;be nzh t.action potential 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 presynaptic membrane;rbby5 z n xk0pt:adsg8u ds*3r2q,)x?
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 resti2fbxex4c/:up ng potential?

  What is not a function of the myelin sheath?

Explain how the resting pot8 +8xvcaml*dr eiv0 f5dz81tz ential is maintained in a neuron.

The diagram represents a synaptic cleft between two neudq9 2xye;cbx6 rons in an insect's nervouy96qx;x dec 2bs 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 structureka.ev(9+isqg of a typical neuron.
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 cpl.r/l 6e)i 60wk b4nknii g8fompounds that are widely used as pesticides. However, there are con0nlbn 68rw46i )g eli kf.k/picerns 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 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 podss5rqi5/93s1l;dtv*+ebiu7tc ozf tential. Which letter represents the segment of the action potential when voltage-gated sodium channels are open and voltage-gated pot5 +ibc tz3dietl9 r*;uqs s7sf 1/5vdoassium channels are closed?

  Which two features are more abundant per unit )5h3pdk ,e .f eufpp+ilength in a non-myelinated neuron than efp,+hkdpepf)u.5i3 in a myelinated neuron?

  Which of the following is a/are correct description(/ 5pq7.35iyab3 nv hxqljzl (cs) of the relative speed impulses ar 3lzqx c .p5n7a3(v qhjly5b/ie 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 process that occurs in the membranes of neuronss k/hbfv (q-f+ during a stage of t+kv(- fh/qbs fhe action potential. What process does the diagram depict?

  The image shows neurons that are found in dog brains. What does fcp72z, n t6xdletter X indicatfd6 pc,z72 ntxe?

  The diagram shows two neurons of equal length and diamet *9/dg89elpw t7i (ahqpzq 4s3 ou;vzher. Which neuron will transfer an electrical impulse fastei(*;o4q83 uaphd gsevhlwq9zt9 zp/7r?

  Which triggers the release of neurotransmitters from the presynapt gmy4jpibl7 hm *0y1:v.qz o.aic membrane?

  Which mode of transport c:1xbwffbmo:4 -19bldad(o bmjld v0ew k +.0do neurotransmitters use to travel across a synapse?

  Which statement explains why a nerve impulse is electricai3yq:i sb +9 )tv-y, qela9ykdl?

1.Explain why a resting pot.kh 2+)k um:u;dm(mxml7 g zooential 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.