What happens if the tcx7obq0g0q9-o jt0v su (kw2ohreshold potential is not reached ?

  At what membrane potential do voltage-gated sod cbd4cs i1;bfvrr,,q))vwm e-ium channels open?

  The diagram shows a neuron2qs**rdi+s a o5fb,z3zwhzv d.g2w5 t.
Which arrow indicates a dendrite?

  How do neonicotinoid pesticides workck :5,,jqa65h sfojit?

  The diagram shows an zhjuw;ck2m/+ action potential.

What is happening at point X?

  Which is the correct definition of salmm( ei;* 4 c2m: nc2p5rg;kf jved+fgwtatory conduction?

Neuronal cells have special membrane properties that 6 ahn/k(jyj; h-it6 :qowdp6qallow their axons to propagate action potential from one cell to another. The diagram below shows a portion of an axonal plajj6q ynk6d-tih6;(/w :pq ah osma 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 presynaptic membrane?4 *wjw*j i,bd 5rpen3a
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 po zmkzz8j5 y* tu98x-lbtential?

  What is not a function of the myelin sheath?

Explain how the resting potential is maintained in(rwjdsg( hl5+ a neuron.

The diagram represents a synaptic cleft between erfp d+11oli7kraavrl;lb.51v2 4lp two neurons in an insect's nervous syl pvla74 llf k1prr2b+1da evio5.;r 1stem.



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 n wwnvt*ctb98i0t7wi ;euron.
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 synthetixf5yygl o2m5o,:d j.yc compounds that are widely used as pesticides. However, there are concerns about their .omyyf gj2 5x:yl,od5effect 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 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 potential. Wom* k lh-(dg0yhich letter represents the segment of the action potential when voltage-gated sodium channels are open anmhd*y g0okl -(d voltage-gated potassium channels are closed?

  Which two features are more abundant per unit length in a non-mc 4*bw0/i by8tlg 0yd:-wndvi yelinated neuron than in a myelinatb :08bncl-vwidwg /0 i4t d*yyed neuron?

  Which of the following is a/are correct descriptiv ctb 5a8royjaigk2f- ,5sl k5a 4-i;non(s) of the relative speed impulses are conducted atiakr ; 2og-58vnay 5 t ,ak-cj54bislf?
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 thpxb8;1wg3sf tat occurs in the membranes of neurons during a stage of the action potential. What process does the diwftp1sx;8g 3b agram depict?

  The image shows neurons that are foue fo+ +p+7jqlbnd in dog brains. What does letter X indicate lo++e7fpj+b q?

  The diagram shows two neurons of equal length and diameter. Which neuron wil ugfa r/(6l)bql trans b(6) urgaql/ffer an electrical impulse faster?

  Which triggers the release of neurotransmitters from th0r/3)6ny axw )mzx mu,sxa;dke presynaptic membrane?

  Which mode of transport do neurotransmitters use tx 5 -,q r9p3rff1byhbpo travel across a synapse?

  Which statement explains why a nerve impulse is e uvoh7:j-jl8fv )t/n mlectrical?

1.Explain why a resting pote5di496ybt*n sl 4 *0-eip ox)hnuecaential 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.