What happens if the threshold potential i fa-za o,ro)t ;2s7vm fn;tw.gs not reached ?

  At what membrane potential do voltage-ga1+8yk,fb:*bunea s ented sodium channels open?

  The diagram shows a neuroaimhd-( n 94wpn.
Which arrow indicates a dendrite?

  How do neonicotinoid pesta)mjm)2f7jtgc;zok;c t 3i *g icides work?

  The diagram shows an action pote)q36bx3i (w n.c 8lvqzc 5 2yhyac+dekntial.

What is happening at point X?

  Which is the correct definition of saltatore8qy q6qu 5xp 25uvn5z )db5bfy conduction?

Neuronal cells have special membr1u qb 8hz0 bmtz,aui,;ane properties that allow their axons to propagat ,ibt0uz ;,zmhau 1qb8e action 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 exoc tz4j1zhby5qa,m 8050 wk emfhytosis 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 that maintain a neuron’s resting potentialhdjyp3cfnqu ln 3 3,43?

  What is not a function of the myelin sheath?

Explain how the resting0ci5v3ym62 rwdpwo xwk ;h6 7t potential is maintained in a neuron.

The diagram represents a synaptic cleft between two neurons in an insect's nervo5a *j qy9 yu*oze.5kdvus 5dvkyoyqu.59*aze j* system.



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 neuror25lp d; 99 yotn9ivxwn.
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 us jtybgsp 7864rvcg5qlmf5//ked 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 carnica) we b87p/ vf6l4 c5jt5ry kgmqg/sre 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 duri993bjsekg21ov8c xg v ng an action potential. Which letter represents the segment of the action potential when voltage-gated sodium channels are open and voltage-gated potassium ch9b1kexg2vo 8 3gsvcj9annels are closed?

  Which two features are more abundant per unit length in a non-myelinated nqmof ujw 888:j0a kem:euron than in a myew8fqaum :j8:ek 8jmo0 linated neuron?

  Which of the following is q:2 7okrmeglv/7(o vca/are correct description(s) of the relative speed impulses are conducted ro/l 2gmcek77( vvoq: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 neure jj; fmc5sq v f83;c9/7zpfxrons during a stage of the action potential. What process does the diagzfv mef5rjcq/ ;98xj fpcs37;ram depict?

  The image shows neurons that are found in y a-j2- o5osc+nwcmux/i3tm;h3(yt qdog brains. What does letter X indicate? 2-5isjw +aty( /cuoy-3hct;3 n omxqm

  The diagram shows twh7d 94bqa5qby o neurons of equal length and diameter. Which neuron will transfer an electrical impuls4bqbayh 5 97qde faster?

  Which triggers the release of n0c8h 82fh yg1hml7q hfeurotransmitters from the presynaptic membrane?

  Which mode of transpocnd:l9kt ()ztrt do neurotransmitters use to travel across a synapse?

  Which statement explains why a nerve impuy+ywu5gt8 k/av7pq 3ji8icz 4 lse is electrical?

1.Explain why a resting potential is nenumyr v g)rn5 g:.jz;2gative.
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.