What happens if the beo-vjv ;,( qiai1m7sthreshold potential is not reached ?

  At what membrane potential do voltage-gated-x+us qiqhv *0y: +b2 ul is-h-:axs nf8z0mok sodium channels open?

  The diagram shows a 43qmu qy;(wjuneuron.
Which arrow indicates a dendrite?

  How do neonicotinoid p1p89.bltlf y9 cvw5 v/j zmez8g8gah1 esticides work?

  The diagram shows an act.6 vr pi)y,isjion potential.

What is happening at point X?

  Which is the correct definition of sal;nfcz4nalxs )wz,5 3u tatory conduction?

Neuronal cells have special membrj d* mwu-es*3-)8 qmb ixa/ubwane properties that allow their axons to propagate action potential from one cell to another. The diagram below shows a portion of-i8bxa 3eww ums-/u)jbm q*d * 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 exocytosisbi3otdot d /6+ 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 maintaib)4nc u(nt)a.uf( anqn a neuron’s resting potential?

  What is not a function of the myelin sheath?

Explain how the restadl,xip:vd6 /ing potential is maintained in a neuron.

The diagram represents a synaptic cleft between two6fm (uo:qf,qdqd5.h r neurons in an insect's nervous systedq hmfr6:, qu.q fo5(dm.



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 e -;*jh2xb/pmm1 sfri 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 that are widely used as peoldo2,b wzw 4e4hv g)9sticides. 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) were treated with non-lethal doses of two neonicotinoids, Imidacloprid and Clothianidin, and the effect it had e,wh o)l4o g24wvz9dbon 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 dur-,r gro2)px s-vs;wu:x fls.ua6.vgwing an action potential. Which letter represents the segment of the action polpxr,wsusv-;fsgr)v2a6 u. . oxg:w -tential when voltage-gated sodium channels are open and voltage-gated potassium channels are closed?

  Which two features are more abundant per unv()cq/mj w 4mrit length in a non-myelinated neuron than in a myelinated ne()mrw/mjc vq 4uron?

  Which of the following is a/are correct description(s) of th/s.b c pnv*/ggjx;uq 02 8p 94tbhgyule relative speed imp*bt./84ycp0 hvqs9 ux jbgg;glu2/p n ulses 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 duri9x)nfms4sl i9ng a stage of the action potential. What processf 49s)xn9l smi does the diagram depict?

  The image shows neurons that are found in dog brains. What does letter X indicahvfmf.rc(** . y i4+d-c dna.zemiua 5te? * mun-ff.r (cd di4hecam.iz. +vay*5

  The diagram shows two neurons of equal length a00skq6 galms0nd diameter. Which neuron will transfer an electrical impul akl gmsq60s00se faster?

  Which triggers the release of neurotransmitters from the presynaptic memwu*)h)yjj(g) dn s9wmbrane?

  Which mode of transport do neurotransmitters use to b4e4yy/ytr +y -zadfq 8c/ ,hjtravel across a synapse?

  Which statement explains why a nerve impulse is electrica9h rkrs)(u r:kkzd1axf8,g)gl?

1.Explain why a restiu qax(,x6;ily+5g-e g gr jh.tng 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.