What happens if the threshold potential is not reachui1-aw((sy (u b) sawled ?

  At what membrane potential do voltage-gated sodidb7x 31klsn +-t //l/auvrdkrum channels open?

  The diagram shows a ne01 d2epxw8 evjyp) qy2uron.
Which arrow indicates a dendrite?

  How do neonicotinoid mw mp3aa x/vo6b1i-avy;5j f) pesticides work?

  The diagram shows an action p x(:5*vk;*4ivm c y6kktyoxsbotential.

What is happening at point X?

  Which is the correct definition of s w 2d:ifuz.rl(49afwd altatory conduction?

Neuronal cells have special membrane propertiesxrs/ gdj6(mf z.zcs*/*zuf/jhq+0 ij that allow their axons to propagate action potentuqj j /ji s/0dfzz+ fhx.*/* m(rsgc6zial 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 w.ntin m9-eayp64v (oq/ vnx,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 maintain a neur, .mp)hy +ncqwon’s resting potential?

  What is not a function of the myelin sheath?

Explain how the resting potential is maintained in a q5e x:s x9(xkgneuron.

The diagram represents a syna 4+6-y ppsunynk s,l*bptic cleft between two neurons in an insect's nervous sysl k *ppuns4ybn6sy-+ ,tem.



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 the1scesbb*qi z3kv )97 d structure 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 synthetich.h*wmmgn+m ( compounds that are widely used as pesticides. However, there are concerns about their effect on nhm.*( mg +hwmhoney 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 duri:u)(e pfh2h n4yg x)3 wj8lrekng an action potential. Which letter repre3 hn2lkyh g(p)r4 e8x)fuw:j esents the segment of the action potential when voltage-gated sodium channels are open and voltage-gated potassium channels are closed?

  Which two features area s/o w0gnixh ohj-sh+(k* 2q0 more abundant per unit length in a non-myelinated neuron than in a myelinated nekhashn2*hs / +0qjxo-iogw 0(uron?

  Which of the following is a/are correct desciyel8hy7s rwoe.zb;)w gjl+6n .d0*q ription(s) of the relative speed impulses +lg*i0b8ozy sr wqj.n.eedylh67 ; w)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 u 2cods3q7ouv6 m )a4qoccurs in the membranes of neurons during a stage of the actid3su7ca qo2v6q ) 4uomon potential. What process does the diagram depict?

  The image shows neurons that are found in dog brains. What qqy93h 0 ycv(va j:ii+fy7k4vdoes letter X indicate? kvhaq y+qfc (7i:iy3 94y0 jvv

  The diagram shows two neurons of equal length and diameter. Which neuron w.8mxc dfso5t, ill transfer an electrical impulc8oxdf,s 5t.mse faster?

  Which triggers the release of neurotransmiw3yqx ;3/ o:m,w-wrpc83gn4wl)rr heh w4rx ptters from the presynaptic membrane?

  Which mode of transport do neurotransmitters 2:vgf4q veh/g use to travel across a synapse?

  Which statement explains why a nerve impulses u /-+ r(kk*:p ynxmhe obv-dnf9e3k/ is electrical?

1.Explain why a resting potentdg86 orh6wi651 dg8skqv wb e8ial 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.