What happens if the thres x4)at)lv5 /wot2jrwu hold potential is not reached ?

  At what membrane potentidm3fo3 3y4oa hhsc.mq t u;-1val do voltage-gated sodium channels open?

  The diagram shows a neuron1ros izc oti1 ,4y6lm9.
Which arrow indicates a dendrite?

  How do neonicotinoid pes+0xfijyu b:(8o;ull j*hjcb2ticides work?

  The diagram shows an actionb( vdp(ml e0a; potential.

What is happening at point X?

  Which is the correctui:(s5a jjpm72wi-a .x a6zej definition of saltatory conduction?

Neuronal cells have special membrane properties that allow their axons to propagtrdyu9h9o0j3 j q2wp7ate action potential from one cell to another. The diagram below shows a portion of an 0 3d9tu jyrj9w p7h2oqaxonal 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 neurotran2 mr.j9n q)+xg xia ,l;.hiy(sx luvy8smitters 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 neuron’s re da:fzjr-d7 a0po u.2isting potential?

  What is not a function of the myelin sheath?

Explain how the resting potential isyf;it wgkn/4uv 3 (or) maintained in a neuron.

The diagram represents a synaptic cleft between two neurons cll(8mz 9mo;l 1:o s5phll9wvin an insect's nervous systec;wls oplll 91h59 l:z8mo(vmm.



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 net g2hga x77,wzq+a73mraf*cl uron.
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. Howe(iznwe3z+ j +nver, there are concerns abz zn(+je 3wi+nout 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 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 anh/+s:ao1vb qov3 kwdpz 1wy-2+i.kfy jzk6l 8 action potential. Which letter represents the segment of the action potential when voltage-gated sodium channels are open andby.ay 6z8j11sk3/whv :f-wdqvol zok+ i2k+p voltage-gated potassium channels are closed?

  Which two features are more a(y x*lwd.7ph yu7zkb/bundant per unit length in a non-myelinated neuron than in*.yuw(xzk h 7dbp/l7y a myelinated neuron?

  Which of the following is a/are correct description(s) of-)zizcsdbo kwr(u- vz;n (,8i the relative speed impulses are conducv zzwu ic(d-);i-nskzrbo( 8, ted 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 procesxeio0n+ yktd4z*w9v1skk nyw 3)+ y2o s that occurs in the membranes of neurons during a stage ofsx t0* k+ 9odz y1)wien2+w 3ov4kknyy the action potential. What process does the diagram depict?

  The image shows neurons that are found in dog brains. Whavxe ++r0xj;qoiyvq /,t does letter X indicatr 0ovqexq/+ x;,+vyij e?

  The diagram shows two neurons of equal length and diameterstsxd ic k5z /il-f6)vicz6t /.w 0rlv*pp*i4. Which neuron will transfer an electrical impu4) icv6irt0*/ p-z6 fclxwt dipv.k*sl/ si5zlse faster?

  Which triggers the release of neurotrans 5gxtc1(wm/b)tci d5pmitters from the presynaptic membrane?

  Which mode of transportz 4q ;o q8q(vtg+gygt157k3 kubfwsj7 do neurotransmitters use to travel across a synapse?

  Which statement explains why a nerve impulsnruj7iqbb;qv8, .j 0 me is electrical?

1.Explain why a resting potential is a(gy. q *9suy/+g-zwsz sj 3znnegative.
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.