What happens if the threshold potentp( )(+ptxxuh oial is not reached ?

  At what membrane potential do voltage-gated sodium channels on4 kcg-xnhp2(cu8 cg+ pen?

  The diagram shows a neurzj m7xov6+.8n 2l1xjh9 ncyg 6fxzkh0on.
Which arrow indicates a dendrite?

  How do neonicotinoid pesticides 8m1v6rin- gj1)a qar8yomm* kwork?

  The diagram shows an actioi kdu1b0y+6 *2czlwj bi3a4td n potential.

What is happening at point X?

  Which is the correct definition of saltatory,qvd rey4g w,) conduction?

Neuronal cells have special membra4hsjq3idd p:d246zog ne properties that allow their axons to propagate action potential from one cell to another. The diagram below shows a portion of an axonal plaszs6 hd4ogqdj :dp432 ima 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 presynapt.6q y0-lsaa:i(ij yohic membrane?
I. Depolarisation of the postsynaptic membrane
II. Depolarisation of the presynaptic membrane
III. The diffusion of calcium ions

  What are the main fap/t+k zo-9empvzld* 1 bcl3e; ctors that maintain a neuron’s resting potential?

  What is not a function of the myelin sheath?

Explain how the resting potential is mai4b4e lg esnfx +q31o(intained in a neuron.

The diagram represents e1dic(qeox4 lf3 b6 90fhhecj dq) 0a/a synaptic cleft between two neurons in an insect's nervous systemce(d)j 6 fe f0ld1/hi0cxeq 9h4qbo3a.



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 typicant92d8m:pu irk, n.pj: + fyrhl 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 coy +-yfvnc;ha 3u4 k3it-t wlpj,l(a3ompounds that are widely used as pesticides. However, there are concerns about their effect on honey bees and ot34lpy- +y w;haf cu3jtal -n3(i,vo tkher 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 jac*ql5+* zkssv4.ql during an action potential. Which letter represents the segment of the action potential when voltage-gated sodium channels are open and voltage-gated potassium channels are clo +s ljz*a.5qvs*k4q lcsed?

  Which two features a bvw7xh6i ca7+f g,x*kvh; kf+re more abundant per unit length in a non-myelinated neuron t*v bac,++kxff 6x;wv gh7i kh7han in a myelinated neuron?

  Which of the following is a/are v( l)+ywo ifgox4:-xzcorrect description(s) of the relative speed impulses are conducted at? wx4 go+lv)xi: yf-o z(
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 op0 8o irrx5z2nf neurons during a stage of the acx8 rr0zp2oni5 tion potential. What process does the diagram depict?

  The image shows neurons that are found in dog brains. What does l1hs17yt gcism 5ye5(rn dqo 49etter X indicate?ry cq7ns(14m ye5h isotg9 51d

  The diagram shows two neurons of equal len bdhtgof-w96ga0h *y 6j6qz -egth and diameter. Which neuron will transfebazy6 t6-qfog-de*wh9 h 6jg 0r an electrical impulse faster?

  Which triggers the release of neurotransmitters from the presynapi kxjit(j069z tic membrane?

  Which mode of transport do neurotransmitters use to travel acrj. u.5l q 1runv365a y*gsdlbnoss a synapse?

  Which statement explainrx25l sgka06:jlu/pk3 d:3caq.lj jes why a nerve impulse is electrical?

1.Explain why a resting potential is negati1qci:u3q e w0ove.
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.