What happens if the threz pi nvv;u(zdsq(g-w9;c3k 0b shold potential is not reached ?

  At what membrane potential do voltage-gated sodium chaxvgd-d9hw; vgnkbc)1lq:e +(ivv16mg 7 rif5 nnels open?

  The diagram shows a neuron. f/2d5 lr tyda+*rpv*s
Which arrow indicates a dendrite?

  How do neonicotinoid pesticides wod q31oy 3zfs1xb h,)uzrk?

  The diagram shows an act( rb-co1*d liiion potential.

What is happening at point X?

  Which is the correct definition of saltatory conl1hdu+4t.g 0x okjb1eduction?

Neuronal cells have special :u77ru(n8sp l g6bvr s)ou3a+d as+ uamembrane properties that allow their axons to propagate action potential from one cell to another. The diagp us3uu)s:(+8 ba +rasard76vl ogn7uram 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 neuro4z)quk6q1 .9 evzj*zo:lodfu vx/2eb transmitters 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 resting potentiai38t3ok2yw3i k+j la9ksfqv-l?

  What is not a function of the myelin sheath?

Explain how the resting potential is maintained in ah g3b,ewwtvj b)2-fi9 neuron.

The diagram represents a synaptic cleft between two neurons in an insect'4iii h :jc;(k.ig5;jc3no dqj s nervou.di4 q jig;i3h;c( 5jkcji on:s system.



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 structus ca24 +rawif+re 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 syntsc)e, hyjh9*ohetic compounds that are widely used as pesticides. 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 carnica) were treated with non-lethal*ho,hy)j se9 c 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 m/vh0rhp6g yvz8rno 3;embrane voltage over time during an action potential. Which letter represents the segment of the action potential when vh pzrvh n;yr 8v0go6/3oltage-gated sodium channels are open and voltage-gated potassium channels are closed?

  Which two features are more abundant per unit i:*twy) /-fcau w zw+itsyo03length in a non-myelinated neuron than in /w- w )i 0si*t ta:zyu3of+cywa myelinated neuron?

  Which of the following is a/are correct description(s) of the relat axxld+u*gspf l9t11/c*ffyu 0o q;t5ive speed impulses are conducty/*c1al ;5f0uxgf+t9 *ot ds1uxflqped 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 neurons d- p8ydn5gj1p2vo3l q dv7o /xguring a stage of the action potential. What process does the diagramjpg -d87l2/dnx qooygv31v5 p depict?

  The image shows neurons that are found in dog brains. What does lettersi. h+(4,3 ozkdfrt1d 8x mknz X indicate? or(1 4ntk3kxs8im,dd h.z+ fz

  The diagram shows two neur54ca, vdwa8)/ baj hw:kujm 6lmw 7o*sons of equal length and diameter. Which neuron will transfer an el lj hbs74a kv8d)wcmwa*m6a/: ujo5w,ectrical impulse faster?

  Which triggers the release of neurotransmitters from the presynaptic membemxo*te7 1cqk-* + pz2xmp8u yrane?

  Which mode of transport do neurotransmitters use to travej ru4h e joofmd-v koo38+f;3-l across a synapse?

  Which statement explains why a nerve impulse is1gzckh 1oe *z,h/7qb g electrical?

1.Explain why a resting potene5i bm0 9,os. z;5xv oihkhd5jxt.l :vtial 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.