What happens if the threshold potential is noty7my.qq v 5ug5 reached ?

  At what membrane potential do voltage-gated sodium channels amd8sl1d2ij/f2 pxo ;bs9 +o8 enhp.f open?

  The diagram shows a nu-uop*e1f s )zbi uav/q2b24d/xh4k ueuron.
Which arrow indicates a dendrite?

  How do neonicotinoid pesticides wopt-lfe kui*1/ia z1d6vp*1h zrk?

  The diagram shows an action potentia, cd/ xhxmfy.:q +a /z8iugqa7w ,evw:l.

What is happening at point X?

  Which is the correct definition of saltatory conkqh z80e s2 wtd0sf7n2m z:8ekduction?

Neuronal cells have special membrane properties tha) ,xo7k+wqud5g 4oz)srnw 1 rkt allow their axons to propagate actionx7w4 rs1o5z,dq)gkn+kw)r o u 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 neurotransmitte2r/zwgs towe 38lk 1x6m6j(e*at vs i9rs 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 thalfd(lm2x.h f7t maintain a neuron’s resting potential?

  What is not a function of the myelin sheath?

Explain how the resting potential is maintain c po surth3/7zfwqo-q+,:e-bed in a neuron.

The diagram represents a synaptic cleft between two neurons in an in ita ksea+sx c)-s;z;,;.v kxpsect's nervous syst.;sk xxe;avc)k+s -zs t;i,apem.



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 struc 7rtd.9pef+ g.;m/ tu:t6mq m el+nssyture 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 sk(4 9wnf4tzy qynthetic compounds 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 m 4(nfk w94ztqyellifera 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 jx9h w) mbp/aq5ton0jn-o* l5voltage over time during an action potential. Which letter reprpa ) /-w5bq*m n 9jthjn5xo0olesents 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 length in a non-myelinated neuronh se;s+) t1/xjd eiag) than in a gah 1 et/));sj xeisd+myelinated neuron?

  Which of the following is a/are correct description(s) of the relative speed ;s1h kwnsm: aqcm- hvit*3*y td3kq,( impulsesh 3c:d q*1s-(ahvmkkn;i ttqm* y3w,s are conducted 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 stq , ,w)c9yt:gk( ga5rl9ekrx page of the action potentiaqrt ( 5xlc9) e 9,pka:y,gkrgwl. What process does the diagram depict?

  The image shows neurons th9nyjb5vwm yshs/ij94p) -s/nk hq1, lat are found in dog brains. What does letter X indicate?hspqy 1/),sn5kjh/ jivmby-l sw499n

  The diagram shows two neurons of equal length /y,(m iyy+g qdand diameter. Which neuron will transfer an electrical i/dgy(i ymyq,+mpulse faster?

  Which triggers the release of neurotransmitters from the presynap,+tbrh* - mczqtic membrane?

  Which mode of transport do neurotransmitters usepx t5*qfqq)0g*rg yj*fcjtnc vj , ,,3 to travel across a synapse?

  Which statement explains why a nerve impulz3o86k:yzojt p+yz y0se is electrical?

1.Explain why a resting potential is negativeeyco6r8 7hl id*xp 0a1.
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.