What happens if the threshold potential is not rewpc lh-m-s u8+ached ?

  At what membrane potential do voltage-gated sodium3ki 7 vj ksb7/v 0lvwuio8:u.o channels open?

  The diagram shows a ;8j;kle w9kl9c apjsqu 5t.tte;,6m uneuron.
Which arrow indicates a dendrite?

  How do neonicotinoid pesticides work?1 qt l cozt zmp06(8urdlin19c:5ins1

  The diagram shows anv*x fw65 q 0sm7+mr;reeyhfkmsan *4. action potential.

What is happening at point X?

  Which is the correct defi5 o *b.w30 a ckk4lj(xnojeu:bnition of saltatory conduction?

Neuronal cells have special membrane properties that allosalo4rcaabu 7d+ d/581 q5 oxew their axons to propagate action potlc7ed4x5a or+o5da81au/sb q ential 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 neurotransmih3fcxfj (oeq 5c5;x2vtters 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 ri(ptphy/.x io7g yj/+esting potential?

  What is not a function of the myelin sheath?

Explain how the resting potential is maintained in a neur0hsgy,p )7 pzjso/;vv on.

The diagram represents a synaptic cleft between two neurons in an insectmuf* d i6t7p-p's nervous dp *u-pmi76tf 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 structure of a typic p6kat5/df4ta ew63.ujx 8foo al 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 synthy wnbl8o6f6+v,s e*qdogw(*w etic compounds that are widely used as pesticides. However, there are concerns about their effect on honey bees a 6 +y(vow8lq*sdn6,*wewfbgond 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 33jiq t7 4d8yucy(wkx ox5nj6time during an action potential. Which lette5o3xk7 y3u 6j (t cynqwi48jdxr represents the segment of the action potential when voltage-gated sodium channels are open and voltage-gated potassium channels are closed?

  Which two features are more abundant per,a tc iq1pyngm/dyfd zvo+ gb2t v5r;6)h+p46 unit length in a non-myelinated neuron than in a myelinated ne it25 +hmng6b qa4);d6 dv1+pp/vog rfcty z,yuron?

  Which of the followi 49hry e:j9 asyog+ylc::oki-ng is a/are correct description(s) of the relative speed impulses are99 agli -: :sycy:+keo4royj h 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 occui1 :wlncqn u8+lq1xwroa3-e q.(x v8hrs in the membranes of neurons during a stage of the action potential. What process q1 lu 8ni :q1+ a.oxenv3chl-8rq(x wwdoes the diagram depict?

  The image shows neurons that are found in dog brains. What does letter X inob-m1ieu5p9 8 vo 04ni g9mst z;ajx,tdicate? - ju9tvxioom95z 0mn1e4g ti ;s,8abp

  The diagram shows two neurons :f6h eip lie fj+3y)b9of equal length and diameter. Which neuron will transfer an electrical impulse fl6fyhj3ip be9):i+ e faster?

  Which triggers the remdl9qz. a -w o55kby1elease of neurotransmitters from the presynaptic membrane?

  Which mode of transport do neurotransmitters use to tracxc 0mr7n 2s0cvel across a synapse?

  Which statement explains why a nerve4 rqb4l/ ry4grul;j2c impulse is electrical?

1.Explain why a resting potemwsf3b;z+z zhz*.w 3 u(3e xbgntial 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.