What happens if the threshold po:w8c m.onic g:blf q00tential is not reached ?

  At what membrane potential do voltage-gated sodium channels oseif e-- qjsx wy)),o9xx t-/zpen?

  The diagram shows a neuronz.-mys3zl m 9w.
Which arrow indicates a dendrite?

  How do neonicotinoid pesticides w1l7lo/rs c *ywiiz,m: ork?

  The diagram shows an act96fyese 1hnv ,ion potential.

What is happening at point X?

  Which is the correct definition of saltatory conductiongjudk+dy 0 :dsned/) 2?

Neuronal cells have special membrane prz3+q ebu ,el4woperties that allow their axons to propagate action potential from one cell to another. The diagram below shows a portion of anqzbulwee 43+, 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 neuryb13s *1vncuaotransmitters 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 resting cvt6.fi nc:7in z6vpa m8zz(7potential?

  What is not a function of the myelin sheath?

Explain how the resting potential is maintained x2xchu0jc* b8,rjks,5q;ce q in a neuron.

The diagram represents a synaptic cleft between two neurons 5k4osw l9ktg3in an insect's nervous systs3kl5t k4wo9 gem.



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 typid: xxggzy ; (z-ae(vh1cal 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 synto6miz:, jg -wjhetic compounds that are widely used as pesticides. However, there are concerns about their effect on honey bees and other pollinating insects. ij m,6gw-o: jzThe 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 ,k o+fc+j )74acmxit vm+va/7cjy.ujover time during an action potential. Which letter represents the segment of the action potential when voltage-gated sodium channels are openv akjamoj ijuxc7.7 yv/fmt+c+4c+), and voltage-gated potassium channels are closed?

  Which two features are more abundant per unit lengj:jen ng;1 ib3ga6(:tg*vlagth in a non-myelinated neuron than in a myelinated l:a g ggnjbeit*61:v; n gja(3neuron?

  Which of the following is a/are c nn+5k7clh mw:orrect description(s) of the relative speed impulses are cln7h+5w:k nmconducted 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 during 4cr e 9-sskvh81dkdnm t *8h,ia stage of t v*hn8sr8ckh4 e k,dd-9ti 1mshe action potential. What process does the diagram depict?

  The image shows neurons that are found in dog braip,ei6m dwjs 19*iul :dm+g(n lns. What does letter X indicate?w1 +dm9*,nmle6l:id(j sugi p

  The diagram shows two neurons of equal length and diameter. Which neuron wx hm7 1+vc(exz.jmf *cn+hd3jeh17 moill transfer an electricalmcm(xo * j+x 3h.vnd7e1 jecm h7+f1hz impulse faster?

  Which triggers the release of neurotransmitters from the presynaptic membrane? 4,cvnfo ek(t;

  Which mode of transport do neurotransmitters use to tc -nef x.si.h4ravel across a synapse?

  Which statement explains why a nerve impulse is electd6a 34ko+; +i 7l1a sbzescshgrical?

1.Explain why a resting potential is negat kc3o ,x,wx0fhive.
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.