What happens if the threshold potential is4 nv/w+- hlg1l2x ykrshl2d:h not reached ?

  At what membrane potential do voltage-gated sodium channels opeiz pbw:2g27.1wn mo l,wq4a i od8s(kkn?

  The diagram shows a ne/vtbj b 4o8 ng+krmr)4uron.
Which arrow indicates a dendrite?

  How do neonicotinoid jb:j u3-unf9 v7 c (iu0lw1ipqpesticides work?

  The diagram shows an z3shdfuozj5+ (.w c gn0y +z:faction potential.

What is happening at point X?

  Which is the correct definition of saltagslpd y9t9 pm2q.z;i .tory conduction?

Neuronal cells have special membrane propertiesu/ wx+n 1ezt95wp 8oej that allow their axons to propagate action potential from one cell to another. The diagram belozuxwt/w eo819pe5n +j w 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 neurotransmitters at the pr63m6xtmp 13:4koftvhp a7xe.hbrap7esynaptic 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 neurew x jztk:fz0vq9 :7*bon’s resting potential?

  What is not a function of the myelin sheath?

Explain how the resting potential is maintain s09kdfn7 rv9fed in a neuron.

The diagram represents a synaptic cle .nvbd7pgjfv5x l5gvz1u1d 9* ft between two neurons in an insect's nervous sfbz1gx udnvg 1jld55.v p *7v9ystem.



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 structue5eb :jgbn18nm 7opp7w- nw.cre 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 compou/d h/p;u9ycpjjge(;s8ax sdts+w3v7 ;qa a5inds 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 hone/a 975 g itq; sj;addpu3;8scsy(he+xwj v /apy 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 shows9+1f9v eg3)9fmh c kwuy 2zzdq membrane voltage over time during an action potential. Which letter represents the segment of the action potqu)dkywf g +c293zzv1e fm99hential when voltage-gated sodium channels are open and voltage-gated potassium channels are closed?

  Which two features are more abundant perp5qvck: p;r 97 e8enfh unit length in a non-myelinated neuron than i7n 5eh9qvc; e:ppfrk8 n a myelinated neuron?

  Which of the following id7yk)dz7/v rlm9t /mm.y jz8w55aou as a/are correct description(s) of the relative speed impulses are conducted at?m/w5zzu58mdtyr 9 olm d a.jyk 7)av/7
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:thcw1 o0g*q w: )tyys stage of the action pc) *:tqhywws1ot:0g yotential. What process does the diagram depict?

  The image shows neurons that are found in dog brains. What does t5bf,46 t5xkfrazo;xu 4dc o 1letter X indicate? f5 k1f4z,tuxxtoo4ra ; 5d6bc

  The diagram shows two neurons of equal length and diameterapftj.x. a5t/2s1)7el xg jgi . Which neuron will transfer an ele x2 )5exaitagg lj1tj/.7s.fpctrical impulse faster?

  Which triggers the release of neurotransmitters; gd8jwsc6h0,,vxrv7e os (di from the presynaptic membrane?

  Which mode of transport do neurotransmitters use to travel across a synapse?b t+7yeemwq)ndh18 r.

  Which statement explains why a nerve im3yr7 u0gj w q*drsrn14pulse is electrical?

1.Explain why a restin k*dkq3 3wfurch;ks79 g 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.