What happens if the threshold potential is not reactp;s+xp cw)n1ov(z7 3sf4yh jhed ?

  At what membrane potential0v waclgrvd;/+77 )umq o0b yx do voltage-gated sodium channels open?

  The diagram shows a neip4 z5;p dy8)eo8aair 2 twiu6uron.
Which arrow indicates a dendrite?

  How do neonicotinoid pesticides work? r5wfdk3lomg;hm2y edg 2o:4-

  The diagram shows an acvme*4jzj*6w i tion potential.

What is happening at point X?

  Which is the correct definition of sda-ht6:-)2 e )2e f sqkjfcjooag +nur-owk*6altatory conduction?

Neuronal cells have special membrane properties that allow their axons : fr/; bue5kvo,z.b zfto propagate action potential from one cell to another. The diag/evr;bozzf.5 k,ub f: ram 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 j:rp lngub wvj /+-mv6 qkf;4(9cn hb/of neurotransmitters 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 thaits;r u:3o ld.t maintain a neuron’s resting potential?

  What is not a function of the myelin sheath?

Explain how the restinyjmu.9wbpdw9 m4 8 za4g potential is maintained in a neuron.

The diagram represents a synaptic cleft between two neurons in an insectczl kx 88f:d6a's nervous systezkcx :6l88afdm.



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 typical neuron. d,ggfcr80 h5zb8n -wv
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 compoug )1sj9kk 9ofqzej l8y375a zpnds that are widely used as pesticides. However, there agp)f1yaq 9je8okjsz95kl3z7re 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 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 ove3xc 76u bgs52 e3qyvcyr time during an action potential. Which letter represents the segment of the action potential when voltage-gated sodium channels are open and voltage-gated potassium channeuys63ec5y7b g3cv2xq ls are closed?

  Which two features are more gv5/r8w rwmu6 abundant per unit length in a non-myelinated neuron thr6w85 gr mvu/wan in a myelinated neuron?

  Which of the following is a/are correct description(s) *h hpeg rs3h,x u5nubm+6,l h/of the relative speed impulses are conducted at?*/b6 urpe, 5+hmx ,h lsghuhn3
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 theu 32i.gk bdx2m3r uzcaohr-2. unz ,*j membranes of neurons during a stage of the action potential. What przdan2b.oc*.h3, ruxm22jrkg u u3-z i ocess does the diagram depict?

  The image shows neurons that are found in dog v 3c (4xjtop 74qeo,fqbrains. What does letter X indicatq tjve(fq3 4 ,p7xoc4oe?

  The diagram shows two neully x5o17 azsp+)cfgdzbcws )w72 t;; rons of equal length and diameter. Which neuron will transfer an electrical impulse fal;2w d c )zb5awg szlc)yfstpo7;+x17ster?

  Which triggers the release of neurotran93jl.f 2qn diismitters from the presynaptic membrane?

  Which mode of transport do neurotransmitter39 yz ilw+ qe7f94 kpb1( vl)lcjrphr)s use to travel across a synapse?

  Which statement explains why a nerve impulse is elec5zhr +hwy) r i++npm;hp 1*pegtrical?

1.Explain why a resting potential is neqq87jc 7vpvf2yn l a+9gative.
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.