What happens if the thres mjrw-avgy iwumk6hs0:d/67 : hold potential is not reached ?

  At what membrane potential do voltage-gated sodiu8l tv7uvaqro6) pi-j 5rsn:kt l/+b5rm channels open?

  The diagram shows a ned e*mtl/3 gny0 dgx7+duron.
Which arrow indicates a dendrite?

  How do neonicotinoid pes:8 fiky3(cxy6 5 fsthjticides work?

  The diagram shows an actiur lt07:h l on205v8 qczhi4w/ js.gvpon potential.

What is happening at point X?

  Which is the correct definitionj-p.*5 meimr,)ryrj1nh9 m oz of saltatory conduction?

Neuronal cells have special membrane properties that allow their axons tok yfgaa3b 4yxm.9q1ol 4lxk;6 propagate action poteloy4g 6yqf;9lkm3xa b14.a kx ntial from one cell to another. The diagram 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 the presynaptic membrane? ef1wydi3x 6f(t u:v2e
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 p +rb (4z6k5 jht2ymvwqotential?

  What is not a function of the myelin sheath?

Explain how the restin: ys8 /b1 go;-xlwzz9yj/g eedg potential is maintained in a neuron.

The diagram represents h*x2ox )3liw*7mtrqc a synaptic cleft between two neurons in an insect's nervous so7 2tlicqmh*xw 3xr)*ystem.



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 nevxw4+. b4+cnh i-p wheuron.
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 pes3 )+aph5v iw;sygjh +oticides. However, there are concerns about their effec5hwaj++;p o hvg iy)3st 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 potenp9s e4rn(epo 6tial. Which letter represents the segment of the action potential when 49s (epop 6renvoltage-gated sodium channels are open and voltage-gated potassium channels are closed?

  Which two features are more x7-,us r4icrwllgnf-56mfm -pp0i g+abundant per unit length in a non-myelinated neuron than in a myelinated neuron?-0 rugi 56p gn- cix7l-+lwf,r 4mpmsf

  Which of the following is a/are correct description(sobgdw1. woj. 8) of the relative speed impulses are conducted .gjowo8w1 b.dat?
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)6e6yp/ lauqxli u -m) occurs in the membranes of neurons during a stage of the action potential. Wh 6ay6/ilupxl um)q -)eat process does the diagram depict?

  The image shows neurons that are found in dog brains. What 8sey6wvp(p2mnyzjo6t8(.f pt( g5ah does letter X indicate?p6ap fy8 zyw8et ng m(5p j2hos(.6t(v

  The diagram shows two neurons of equal length and diameter. qoqiso6; 9g4q Which neuron will tra9isgqq q6o4o; nsfer an electrical impulse faster?

  Which triggers the release of neurotran)euos17 : 3bs sblim(msmitters from the presynaptic membrane?

  Which mode of transport do neurotransmitter82 xx p4i9sj t8kinjaq9gxu5+s use to travel across a synapse?

  Which statement explains why a nerve impuls v;tiddmm:y(t hclyz-+;2lx2 e is electrical?

1.Explain why a resting potentiazjqqa ajmq u+, fcrlm)4l8+:/l 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.