What happens if the threshold potential is not reac.yaxp f80 rgxs,.l d7lx gtwnz5-t o99hed ?

  At what membrane potential do voltam de zi)3qe; nl,.wi.rge-gated sodium channels open?

  The diagram shows a ne)u t9 o6roo6apuron.
Which arrow indicates a dendrite?

  How do neonicotinoid pesticides n .hc;f 6j5o2hr 2m kom-zr;hlwork?

  The diagram shows an action pot5ic etld7(r f ,sgvf7*ential.

What is happening at point X?

  Which is the correct definition of saltatmx- 42iq kls4qory conduction?

Neuronal cells have special membrane properties that allow their axonsxjv k/n-)tkng 5d7w esx+:*fd to propagate action potentivx/j7-nk)sx gnd+e* d fk5:wtal 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 pres(k.zk.jxxd :o7 +ah cgynaptic 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 : wso07. yy:fy:oitzqresting potential?

  What is not a function of the myelin sheath?

Explain how the resting potential itllh/ti -o6- is maintained in a neuron.

The diagram represents a synaptic cleft between two neurons in an insect's nerv;tyc-u9 tq s83v1 cxeuous yevst-19cqx38uut ; csystem.



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 ssv)l p:tof u2z :,v)attructure 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 synthetic co eaphl:p )7frdzqf ,.2mpounds that are widely used as pesticides. However, there are concerns about their effect on honey bfdql) 7ha e2fzrp ,:.pees 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. W01tbea w..;ftx e 8i)- te.gucl *drkxhich letter represecg.e*a uld.fk1. 0t ttexrwe i;)- 8xbnts the segment of the action potential when voltage-gated sodium channels are open and voltage-gated potassium channels are closed?

  Which two features are/ a;bw b(qyv*ai :6noxq 32asa more abundant per unit length in a non-myelinated neuron than in a myelinatay2aaaq xo:qb ;w6b(s/*vni 3ed neuron?

  Which of the following is a/are correct descr e n8(lmkcvv6 s16fx)liption(s) of the relative speed impulses are conducted anx )(ef vkl61s8m6clvt?
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 i9j3 ::0x 7xtuo cvds 6ylkf9sdn the membranes of neurons during a stage of the action potential. What process does the dia0of vxtu:9d7s 93s:k xj6lydc gram depict?

  The image shows neurons that are found in dog brains. What does wn 24iw gj ,8ofk6k3o*:tezec letter X indicatee4 *k8oi t,:32 zekwjowfg6c n?

  The diagram shows two nem (4 g4ajmx.gfpk3xw9ww57ko8p bja9urons of equal length and diameter. Which neuron will transfer an electrical i(w o k98.x mg7 wgp 5a93baw4fk4xmpjjmpulse faster?

  Which triggers the release of neurotransmitter ;4 yeqjz-0x7, wgcfc-/deyaes from the presynaptic membrane?

  Which mode of transport do neurotransmitters use to trave-7+ v+yklo quvl across a synapse?

  Which statement explains why a nervnoy c/yzc *4 93.kwjg:ibu8 bre impulse is electrical?

1.Explain why a resting potenti6 uxq4x(n.gvth /:qqa05rzt xm* 9huial 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.