What happens if the threshold potential is not reac2u4 +5fwj e0th lid2ozhed ?

  At what membrane potentvt,.y voi u n88 f07r2uytsh/nial do voltage-gated sodium channels open?

  The diagram shows a ne;ask0q)o6ky zt- nuu*uron.
Which arrow indicates a dendrite?

  How do neonicotinoid pesticides work4k(zaaq x+;u 88ien6apmt.v o ?

  The diagram shows an action pm,,uoppr 3 d97m reo:potential.

What is happening at point X?

  Which is the correct definiti-;eeqobxtvkq1vupz /9lc2 z;*7m m+ron of saltatory conduction?

Neuronal cells have sp:1vnhjx )5g8)iwb ojuecial membrane properties that allow their axons to propagate action potential from one cell to another. The di j5hv1xbjug)wni :o) 8agram 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 neurotransmitters at th/f7*qbsqcqjt5 dkrc5 6:1 das e 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 negc;t 855u m8h ami+flluron’s resting potential?

  What is not a function of the myelin sheath?

Explain how the resting potential is maintained in a no3- 5( x h+vdi aiqtg+z2nrtdp(3v(qr euron.

The diagram represents a synaptic cleft between two neuronskwrri3t ( 8qy2 in an insect's nervous (qrtyk3riw2 8system.



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 structqwode4fa 9,/xure 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 pesticidewxba f;5 (dut6s. 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-5d6w tb;x(u aflethal 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 tcgo so8p utf3 l/s9/s7ime during an action potential. Which letter represents the segment of the action potential when voltage-gated sodium channels 9gt 3lp/ /s s7of8cosuare open and voltage-gated potassium channels are closed?

  Which two features are more abundant per unit lz:.3c3.g ywm; ;muczhs lbz9 rength in a non-myelinated neuron than in a :s;h c9y.mlg bz .mz3urcz3 ;wmyelinated neuron?

  Which of the following is a/are correct description(s) of the relative speed imna u7ne lts)x(h0* vd3pulses are conducted at(3sdltn7h0)xn a* uev?
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 prkj,kxwce. 1.3z cpvf1ocess that occurs in the membranes of neurons during a stage of the action potential. What process docjvcwkpkz.x f .1e31,es the diagram depict?

  The image shows neurons that are found in dog brains. Whang 7:fh9 r)lmnx) b x 9v 3ih6fmmvun-jl;k5o1t does letter X indicat fn;1f k:m) bhrni6gom3)mu 5lx-j9nv79lhxve?

  The diagram shows two neurons of equal length and diameter. :ab. ps.ckye ,Which neuron will transfer an electrical impulse p.ky.:abecs, faster?

  Which triggers the release of neurotransmitters from the presynaptic membrane n98nuh) rfsd7?

  Which mode of transport do neurotransmitters use to travel * j+m;m; cfvjuacross a synapse?

  Which statement explains why a nervl)z3 +a-u mk)opsv+q ge impulse is electrical?

1.Explain why a resting potential+pas esxo+g gn ;8(1vc 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.