What happens if the threshold potential i3bnqex 3v/kz ;s not reached ?

  At what membrane potentims dmg997bp.x al do voltage-gated sodium channels open?

  The diagram shows a neuro.i nxh+w : jdi:pj49l/k7 rxmzn.
Which arrow indicates a dendrite?

  How do neonicotinoid pesticidvh 5oi um 9 umgl*lp30:lbn9q2es work?

  The diagram shows an actio hjbybp/* pu1oq m-zh d605haym.u7hz+9k6 gun potential.

What is happening at point X?

  Which is the correct definition of saltatory condzc/80 nfq(jxcki d7z3i85xh drjq9p0uction?

Neuronal cells have special membrane properties that allow thei:xk4: ehm1j bir axons to propagate action potential from one cell to another. The diagram bel hb: kiem:x1j4ow 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 presynapfdp6 ww htb2z w z,8d*3x* cm9jhm.g7otic 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 neuron’s 2rm p8( *qh.ntb.c9eqbd,a /nk u hee/resting potential?

  What is not a function of the myelin sheath?

Explain how the resting potential is maintained in a ne6j t);k2ljj/qp y+b cuuron.

The diagram represents a synaptic cleft between two neurons in an inse2 e11 ex4uzgntct's nervous systn14 2z etgxe1uem.



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 neuron.qrmn; r7 jx)v*im :pdzvg353u4.bj bq
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 pesticides. 83disv s vw+50 tu /m(m-zrii:b cdw;7 vicwf2However, 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-lethal doses of two neonicotinoids, Imidacloprid and Clothianidin, and the effect it had om7dvbw3 fwwdcc5s i ;m/i8vs2z 0iv -t:(+irun 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 overr3m:o 7z p(z38dxocf7hs;s6n odip c( time during an action potential. Which letter represents the segment of the action potential dpd fnxz383:7chs orp( s6 7mc;i(oozwhen voltage-gated sodium channels are open and voltage-gated potassium channels are closed?

  Which two features ar4ase.tl e y54g6jgx 0khr; 2hve more abundant per unit length in a non-myelinated neuron than in a myelinateeht s2j6 ge 4y;.h agvl05kxr4d neuron?

  Which of the following is a/are correct description(s) of the relwopdxu l6+ fug 1+(m0cative speed impuulu+x pdg 6wc+m0(f1o lses 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 occurs in the membranes of nuug w + 60vc10shkc8uweurons during a stage of the 0k8 u +wcg uhvuw0c1s6action potential. What process does the diagram depict?

  The image shows neurons that are found in dog brains. What does letter X etczi q t.( l0j3-hwm:indicattcl.( -3e hjmwq:i tz0e?

  The diagram shows two neurons of equal length and diameter. Which neuron w8c1o3s --va7jjy kqv gill transfejoq31-y -cav8kgsv 7jr an electrical impulse faster?

  Which triggers the release of neurotransmitters from the presynaptic membrankg(08 cf ek5 ia.5blkb5 aqfo0zsy/p1 e?

  Which mode of transport do neurotraeh yi9+g34ua/p fvil( wy w5(lnsmitters use to travel across a synapse?

  Which statement explains why a . u drug7a3,tnsjleh; m.5a;w nerve impulse is electrical?

1.Explain why a resting potential is apb0,l-zen8rj6qg1 xhuq; 0vg /ln r7negative.
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.