What happens if the thresk w95hau/osv5x ix,o2hold potential is not reached ?

  At what membrane potential do voltage-gated sodium lsuhw- yql.44 2lvp4pl :2k gvchannels open?

  The diagram shows a neuron. kmcnjm 3p1i,/
Which arrow indicates a dendrite?

  How do neonicotinoid pestiyux6ij f yi),)*af(lzcides work?

  The diagram shows an actvsa , f64fzd9m* cemro/p oy:)ion potential.

What is happening at point X?

  Which is the correct definition of saltat;n.8ql ed8kh g0bt )0,ceo msgory conduction?

Neuronal cells have special membrane properties that allow their axons to phmw4 wqae 1 (qmr15.sjropagate action potential from one cell to another. The diagr e (mwq1sha4wmr.51 jqam 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 neurotransy/ kmd,-au0x+w t48gh cr7mq5db ana:mitters 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 maintaib mc2ryj;*os,x ,vak 9n a neuron’s resting potential?

  What is not a function of the myelin sheath?

Explain how the resting potential is maintained in i,*nuo5 h- (clj 2 fglbwc:4wia neuron.

The diagram represents a synaptic cleft bpk8jys f*+ ep0etween two neurons in an insect's nervous systemj+e y p0ks*8pf.



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 ts +pdfl0sht9h x)i/,qypical 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 tu5n xe2 19ok ttes87aas 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 doses of two neonicotinoids, Imidacloprid and Clothianidin, and the effect it had19s 7ttxteou8e n25ak 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 potentia;rgac0aszg9y i: imoc *-*6 crl. Which letter represents the segment of g 9o*yar zr acis0*;6-cg:icmthe action potential when voltage-gated sodium channels are open and voltage-gated potassium channels are closed?

  Which two features are( (7ynihbibwa(3 3dldhjzr /4 more abundant per unit length in a non-myelinated neuron thah z437(i bbahw (y nlrid/(3djn in a myelinated neuron?

  Which of the following is a(qud1w f8)3wujn; hkj(,hkfi n. 9vrs/are correct description(s) of the relative speed impulses are conducted at? 3,v;w81ihrf.kdsfuj 9q( uwh)n kj n (
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 x/s+ 7 *ind6g. a5mkaohg 2rflduring a stage of the action potential. What process does the diagramn+*/l5g. 7i2k6 aomahfgrsx d depict?

  The image shows neurons that are found in dog brains. What dpefa f*k:tvt/*i5 v if2)td0noes letter X indicate?na 52e:vp*fiid0) ttfv/*fk t

  The diagram shows two neurons of equal length uowylz68, j3 wand diameter. Which neuron will transfer an elecu , l3y8wjoz6wtrical impulse faster?

  Which triggers the release of neurotransmitters from the pre smnr -z*1nsqkc96pq/ )acp ;hsynaptic membrane?

  Which mode of transport do nr l0zq*h43c;o 2 oxfvceurotransmitters use to travel across a synapse?

  Which statement explains whyrg70s x zs;gqr(rv0w,a 3d j 3:gtjhp: a nerve impulse is electrical?

1.Explain why a resting potential is nejy cg9 (1yx4*bh6eru jgative.
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.