What happens if the threshold potd :5 mq 2jr 40/fbutbsewsxs07ential is not reached ?

  At what membrane potential do voltage-gated sodium channeg5c6dhvh2b v*ls open?

  The diagram shows a neuron. .zgghg4x- k z 11.jnwgj*n 8lq
Which arrow indicates a dendrite?

  How do neonicotinoid pesticides 4ujny xuuu7f0zn0d69work?

  The diagram shows an action potential. lsb8m qjv(u3 rsrl4 uh,y95y1

What is happening at point X?

  Which is the correct definition of saltlquysw*1dk- w/e n1l.atory conduction?

Neuronal cells have special membrane properties that allow their axons to 6xqb39wy,rw+ 2foeolp 1 fjm5p7,dvzpropagate action potential from one cell to another. The diagram below shows a portion 32w,worl 9,o6 ypef1m5fq+b dx 7pvzj 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 exocytosu 5-9;fc fvohz- gepyi* 3hp4ftb+pc2is 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 potentiapd6/rqpzmr :w626 d4bbr) dqzl?

  What is not a function of the myelin sheath?

Explain how the resting potential isn yby47k +hda;i3 q82ivont j* maintained in a neuron.

The diagram represents a synaptic cleft between two neurons3vfs(i 4 um6. zqb1kp ogi.pc3 in an insect's nervous system. 3z1bui4sg3v.6( kq pcif pm.o



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 6w s bokd4 :j c.zdtptv,q az58,*a4cdneuron.
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 used as w j+tzhq-5 ,jdpesticides. However, there are concerns about their effect on hone z-hq+5wjd j,ty 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 m1;x+u3 h-+ yrpjgzbqj embrane voltage over time during an action potential. Which letter represents the segment of the action potential when3bug+z-;j yhqrj 1p+ x 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-myeq9z)k5puzk+ i n+mp :elinated neuron than in a myelinated neurouzpkz i9+:+nm p q)5ekn?

  Which of the following is a/are corre,8ftb+dyfbf0i::uhp 3jb yz) ct description(s) of the relative speed impulseht)b0jfzdu+8b i,p:f fb: y3y 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 neuronsr,mf6 r8s ,frmy-aum( during a stage of thf r8m- (srur6,,yamf me action potential. What process does the diagram depict?

  The image shows neurons that are dw( *hvs zsc+,found in dog brains. What does letter X indicateswzhc sv(* d+,?

  The diagram shows two neurons of equal length and diamete0c*mj0xc*gzh peuf ;9r. Which neuron will transfer an electrical impulcguze0f *h p;0xm9jc *se faster?

  Which triggers the releam* ,abt6f vh4p ,qnx(qjm8is7t 6 r7jvse of neurotransmitters from the presynaptic membrane?

  Which mode of transport do neurotransmitters use to travel a u9 *amxddt*4e:sr :kocross a synapse?

  Which statement explains wn/twlkh8s,v4-) o , gfqmx1-8 oieopthy a nerve impulse is electrical?

1.Explain why a reste )2 .sqre:a 8 ds/viw)ull*s/ ppvm0;qyohb; ing potential 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.