What happens if the threshold potential iu 034t fw2o ;idz4..s aa8 ltukcvxz(zs not reached ?

  At what membrane pottyjkzt; 8h 6u)ential do voltage-gated sodium channels open?

  The diagram shows a neuron.y8 8:r(bmgp(bxvi 3c* bxj de.
Which arrow indicates a dendrite?

  How do neonicotinoid pesticide;u; ao (krfh+ls work?

  The diagram shows an action potential. 4s0;tx wnio1rv: bnbq2+ m(wt

What is happening at point X?

  Which is the correct jogzjc0*j-6xk)t m) qaez0 7kdefinition of saltatory conduction?

Neuronal cells have special membrane properties that allyb/57y( d,8m fy fdqc/d sl1jyow their axons to propagate acts(/ cyjfy,dby 5qf17d/ dylm8ion 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 ;oqc 3psu q8)fat 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 potentialjueh3oxq m)qv,v8nz0 sz, d+41nnen7?

  What is not a function of the myelin sheath?

Explain how the resting potential is maintained inh 5:lcngbjz;qra6i+fpi 11o + a neuron.

The diagram represents a synaptic cleft between twod*0;yik4t j /lkv irr, neurons in an insect's nervous yvt r,0kd/4;klj*ir isystem.



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 str2l hw3/g 2dwl,y0cnwc ucture 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 comb .rjw).jtjc3z h,0nzpounds that are widely used as pesticides. 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 carnzjr,)tz 3j0bcj..h wn ica) 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 during an action pky87o ye cupt0eg(-d2otential. Which letter repr8ygoe kp u(c02-t 7dyeesents 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 unit nr(pp96k7 v ualength in a non-myelinated neuron than in v7p6nkap(r9 u a myelinated neuron?

  Which of the following is a/are correct description(s) of the relative2nt mf8fuo*. d speed impulses are condu 8tm*of.n f2ducted 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 a sta/pqh1)q5 .s ronbhnl0 ge of the action potential. What process does the diagram )sqo rqh/ .0pn51lhnb depict?

  The image shows neurons that are found in dog brains. What doesp5v -ov:g c:gsbt9z7c 9ctvk2 letter X indicate?7gt- p z5vk9:btv2vc sc:o9g c

  The diagram shows two neurons of equal length and diameter. Which neuros dkh9u(to1b 0 y ynv18yg;(kmi4p .xpn will transfer an electrical impulse fasm891 o.y1tngx 40vbhkpy( yd ki(sup;ter?

  Which triggers the release of neurotransmitters from th(xiu:/ oc7w, sla3 uwo k2*ckse presynaptic membrane?

  Which mode of transport dgn.:q ,o ttn*no neurotransmitters use to travel across a synapse?

  Which statement explains fk, 0*gvxb,xqwhy a nerve impulse is electrical?

1.Explain why a resting pot+q tt6fbx ujdz mb;k6,h1 n;9jential 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.