What happens if the threshold pox .c4q,qarhu5 tential is not reached ?

  At what membrane potential do voltage-gated sodium channels opa(buq.0l;0. d4jwzkv uzxel: en?

  The diagram shows a neuro0ho53ush bo(25bdr oin.
Which arrow indicates a dendrite?

  How do neonicotinoid pesticides wor8c 8dbdaafe)n6y 3jhw9/0ve pk?

  The diagram shows an action pota;y 5 xe00hep m3ws-koential.

What is happening at point X?

  Which is the correct definition of sajqzaj vfc 2 dr,89gjyb(k83:2hnby n. ltatory conduction?

Neuronal cells have special membrane properties that allow their axons u+qqgo)j8a :jajd g:m -7t(ua -grx*z to propagate action potential from one cell to7gjd q:xtag-)8 ja* auuzqr-(g:o+m j 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 thwyuh s: (yrg ;i-t/q-ve presynaptic membrane?
I. Depolarisation of the postsynaptic membrane
II. Depolarisation of the presynaptic membrane
III. The diffusion of calcium ions

  What are the main factors08+fwob4gea/emb9 z kr5 xcm - that maintain a neuron’s resting potential?

  What is not a function of the myelin sheath?

Explain how the resting potential is maintained in a net kr0raa:30 *tvvn05 anjx.wiz 6ll6guron.

The diagram represents a synaptic cleft between two neurons in an insect's nervqbkf48zv/(2/:wp idvu;8v d4n qk jvnous systemj/d2ku vn fi488p: k;bvvqw(d nvqz4/.



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 structurewjgkc v+ u0k(n+.iy; w 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 pesticide l3l5-+ijtrf d1yu(g js. However, 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 5+jtlud1 firj( -3g lynon-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 membrht 5;kei0 jj-aane voltage over time during an action potential. Which letter represents the segment of theij0 kj ahe-;5t action potential when voltage-gated sodium channels are open and voltage-gated potassium channels are closed?

  Which two features are more abundant per unit length in a na:ni ;ndrjl4ne2 8mnn3lv2 s8on-myelinated neuron than 3v 4md2nsll n8nrn8;nija 2 :ein a myelinated neuron?

  Which of the following is a/are correct descriptrww7sjsr/6 +yil9zi a*/ d*nwion(s) of the relative speed impulses are condu7/rrwia6 wlz/ w*d9 ysnsi j+*cted 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 neuk, e6.16nht 8lpdpvfrvt ( aw-rons during a stage of the action potential.t.h 8v r6ndp(vpkea6,1ft- wl What process does the diagram depict?

  The image shows neurons that are f;g,f:)qfxera* +h 9whi j5w za:iii 3aound in dog brains. What does letter X indicate?3a,+iq9i; wxf g )ri:iawhfh zj5e:*a

  The diagram shows two2k8 d yg)f;uk+ n/knpc neurons of equal length and diameter. Which neuron will transfer an electrical impulse fasteryk;8pg+nckf/ nku )d2?

  Which triggers the release of neurotransmitters from the presynaptic membrane?iv*:0ly7zug:w1y zyz.7ou8: l zw rxt

  Which mode of transport do neurotransmitters use t -we4dxd1k.s m7+y70s /d6epls mownno travel across a synapse?

  Which statement explains why a nerve impulse ou hbs+l 7a3m:s)m)xf is electrical?

1.Explain why a resting potential is nega jp-m j,jbv:b1tive.
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.