What happens if the threshold potentik1kd vg20fcrf+q5 n.(su z8byal is not reached ?

  At what membrane potential do voltage-gated sodium c u v,graz(76q o 89rwb/y6jqdmhannels open?

  The diagram shows a neur zcmf-b(d0 ym6on.
Which arrow indicates a dendrite?

  How do neonicotinoid pesticides agtj +4 n0w6iswifp8b:s r -0ework?

  The diagram shows an action potenti cy3hj z4s. s1ht1/ s:zen,sijal.

What is happening at point X?

  Which is the correct definition of x .)r-gv qye8*zsvz6 qsaltatory conduction?

Neuronal cells have special membrane properties that allow t w;gdlm1s,19 sg,gl(c -ou zxzm/qw sryjc/05heir axons to propagate action potential from one cell to another. The diagram below shows a1 wm,/,cj osdu0y9glsl w;zz/qrxs5(1m- cgg 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 neurotransmitteri:9cr:+ d 6mv(zkqpndnv6oe6brwl m ;((on/ws 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 neuroc(5aw17l5zk sa 1 qli8frcqmq g)x.0hn’s resting potential?

  What is not a function of the myelin sheath?

Explain how the resting potential is maintainecgmw) gpa 0(.fd in a neuron.

The diagram represents a synaptic cleft between two neurons in 3;zpjkb52 m3m4 j3nwfep(s duan insect's nervousp 5m( 3fu3zjes;2j 4mdnbpw3 k 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 struct t0eq ptl0+641ijus cjure 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 compounds tha zlf9 9mpn 4: ihp8wblm92drw9t 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 mellifer9 f92zw rlpl:4p89b9wd minmh a 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 over time during an action p,t.(-cgww9 dox1 -bt yd o1izw 8s8,vdczfxq*otential. Which letter represents th 9dg-,cf8v1t*y8. xidodcw(wzw- z1, to bsqx e 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 lengk mav1bl,d+8yth in a non-myelinated neuron than in a myelinated neurd,abl +81mk vyon?

  Which of the followinga)3 3eu6 pwppc is a/are correct description(s) of the relative speed impulaup pcwp)e336 ses 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 neurony5fbz9 chb.*-mwg4ruwitrja1h / f8,s during a stage of the a mr.uw fr,-4i fw85h*bbt /jcgz h1y9action potential. What process does the diagram depict?

  The image shows neurons that are found in dog b i,(k )5wprq9w ectcw(rains. What does letter X indicate?)(t9c5rcw(e wi wkpq,

  The diagram shows two neurons of equajt lf 6)lan(rls:ejzb* s 0f2vui)-9i l length and diameter. Which neuron will transfer an elect:tvbii lf)j)l-ufrs * 0nlj e6s2(9zarical impulse faster?

  Which triggers the release of neurotransmitters from the presynapti)mlq 9ets 6o( vnequ+lgj92 o)fnu23sc membrane?

  Which mode of transport do neurotransmitters use to travel2 u)zt h-siv:t across a synapse?

  Which statement expla,* an- ,eo f7u 77 ktueeh;mnm/sdb*vains why a nerve impulse is electrical?

1.Explain why a resting potential fa;9 h(q4fxwnzt 9/yg 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.