What happens if the threshold potential is not reach* g-m novce.1 c.qnv;,7s/icjyqv0khvr bw27 ed ?

  At what membrane potential do voltage-gated sodiu/uvocr/ i +owz+*6tb xm channels open?

  The diagram shows a neur1f p ca*xzs9 uzr/q29jon.
Which arrow indicates a dendrite?

  How do neonicotinoid pesticides workt ;lzzc1e,ma1x xa9;n dx -l(iwhgpq -n81op6?

  The diagram shows an action potentiau; 7j ow6pa4vrxo trbteo3 7,9l.

What is happening at point X?

  Which is the correct definition of saltatory + 6llhc3 tj1anconduction?

Neuronal cells have special membrane propertieq*n* :iod ysa l2.jsdi y wulgfz/*(;*s that allow their axons to propagate actzyola**jqs; (il* ddigwfu/n.s* y 2: ion 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 mem-9nsja ty/kd5 t+m zhh-ys1 okr0 d34ybrane?
I. Depolarisation of the postsynaptic membrane
II. Depolarisation of the presynaptic membrane
III. The diffusion of calcium ions

  What are the main factors that mai)ic 0jgdhl;j-g bs*a 6x5f wyv8+zq x-ntain a neuron’s resting potential?

  What is not a function of the myelin sheath?

Explain how the resting potential is main.v+ hel6e, iubc*2 ugatained in a neuron.

The diagram represents a synapte8whm)bounjb6-gh4izn , j /0ic cleft between two neurons in an insect's nervous system.8ih )wb n,jgozub/4 0nme-j6 h



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 sw iz 5 6q+-r hx1;fs+i5bhpsqptructure 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 compounds that are widely used as pesticides. Howp6iplvwj.bld/; 7k iuiea.0*/ v8 zlyever, 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 hzlj; yp6pd a* 7/i.8kv0bii.vlewl/uad 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:9um) m aid2wk over time during an action potential. Which letter represents the segment of the action potential when voltage-gated sodium channelsdm 9 mua2k)iw: are open and voltage-gated potassium channels are closed?

  Which two features are more abundant perm vl8t2lr9c.evc (w-p unit length in a non-myelinated neuron than inewv89r.c(-vlc t m 2lp a myelinated neuron?

  Which of the following is a/are correct description(s) of the relattpgns ha6 k +se(jtbh. 8):ag3 ssf3q9ive speed impulses are 3t:kshta(6fsn9.gs + ph3jqg8 s e)baconducted 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 neurons duptda/ w ki.39dring a stage of the action potential. What process does the diagra. wt39iakp/ddm depict?

  The image shows neurons that are found in dog bra9jnzri .rz(3 zins. What does letter X indicaten .3zzz rr9(ji?

  The diagram shows two neurons of equal length and diameter. Whmwva-. 0oombr/ 76 vcdich neuron will transfer an eledbvvm/o c0-wam7r .o6 ctrical impulse faster?

  Which triggers the release of neurotransmitters*xsd9r34hwgxptz l. sd)4k + p from the presynaptic membrane?

  Which mode of transport do neurotransmitters use to travel across a synapse?fbvce/ )o )n+a

  Which statement explains why a nerve impulse is eleck6mt0 o xv4kus+u6el,trical?

1.Explain why a resting potential is negativew zz:851; sfysz5ra2*h bvd*bzko6q w.
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.