What happens if the threshold pom7qxh zd6n ba5 su)(wvid8n.-*tx 7udtential is not reached ?

  At what membrane potential do s cjx(v/a8tl */7nqauvoltage-gated sodium channels open?

  The diagram shows a neuron. * unh-z*bdc.m2yyq 0q
Which arrow indicates a dendrite?

  How do neonicotinoid pesticides w*zud; 2ez ; cb6ane3b7vk3nbzork?

  The diagram shows anzu3 lvr4/(/yp zo.lu 7kv;x ku action potential.

What is happening at point X?

  Which is the correct definition of 7b5l qs8x2 siyh3nse/ saltatory conduction?

Neuronal cells have special membrane properties that allow their m;e51xe w+a: tl mcho,5m e)viaxons to propagate action potentaehxmw;,15e) m etm:o l5vi+c ial 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 neurotransmittrpwg 2j.9 ,tok8 i;lwhers 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 neuronim3ij6sfjms94 c375zmg 3r nus 0lct) ’s resting potential?

  What is not a function of the myelin sheath?

Explain how the resting potential is maintaix,liy. c tb9r9ned in a neuron.

The diagram represents a synaptic cleft between two neurons in an insect's rqvoid +o4w n5nse1)y p zs014nervous szdne)q14yoi1 s+ wr5psn4 o0vystem.



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 ofz vr22ga3sz:9a uc8 2uh6rrhg 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 pestigac lutgmuvz 9;x/36 +cides. 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 car z; 6 lmauu+xgc3vtg/9nica) 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 metip-6 l( : nuxx:jlrc;mbrane voltage over time during an action potential. Which letter represents the segment of the action potential when voltage-gated sodium channels are open and voltage-gated potassium channels are clos i :tnxcl;6ljrpxu-: (ed?

  Which two features are more abundant per uwv3zf,-w erubljj: 8z-i fdu71;kq2 pnit length in a non-myelinated neuron than in a myeli-wpb7rf j ezqku,i1- l;28v 3jzud :fwnated neuron?

  Which of the following is a/are correct description(s) of th ra9y ich cr29t/1)0jrzte m6xe relative speed impulses rc96)ttr9ij0hr e m 1az/y2cxare 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 in2rr xu1 y, +zr0su zw0k48bz rl5lzhssy*bh+5 the membranes of neurons during a stage of the action potential. What procxwzr+ us, y 5 r401 0h+zzlyzbl*rhssb5u8r2kess does the diagram depict?

  The image shows neurons that are found in do8+ hu kl6rs .*oapf/f:uha2f ug brains. What does letter X indicatefufsh fa6 ul .8*hkuoa:/ +p2r?

  The diagram shows two neurons of equal 3dx f5/snp)q r,t kn)tc9skm8length and diameter. Which neuron will transcnmq tpd kxr,)fn8tsk/s95 3)fer an electrical impulse faster?

  Which triggers the release of neurotransmitters from the presynapwtwlrd/m9 )h* tic membrane?

  Which mode of transport do neurotra4lw u6lr)xkm7 nsmitters use to travel across a synapse?

  Which statement explains9 kym za1r 8)(vipoo3m why a nerve impulse is electrical?

1.Explain why a restinaet 5 h ivbj9tuyf/uz.9.s 2.wg 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.