What happens if the threshold potenvltl4 ve7nzy8*sbj2- tial is not reached ?

  At what membrane potentiaor r9e6b,s 0)iqrj7qol do voltage-gated sodium channels open?

  The diagram shows a neudb7 xr1 rz+i 11 yhq+plkd36lcron.
Which arrow indicates a dendrite?

  How do neonicotinoid pesoql;)cc; nuvgv. 7evr*bp+m na)( -l mticides work?

  The diagram shows an actijzwg bt tdom,-3:5cc,on potential.

What is happening at point X?

  Which is the correct definitiozn4w7kt)hfg i ;jtc9j* k5g1in of saltatory conduction?

Neuronal cells have special membrane properties that allow thei913u+inn4oloy (( o,ggickzi tbo;4p r axons to propagate anzoi on3l(cg1,ii9+uo( bgpo 44;kty ction potential 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 presynaptic membraoqytq7 dj:z b/; ,uk6yne?
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 (g*t4tzx1lpdh8*4-qjlmhe e potential?

  What is not a function of the myelin sheath?

Explain how the resting potentc7;odk15 ai k:r xc7dfial is maintained in a neuron.

The diagram represents a synaptic cleft between two neurons in an inwb2 (nz nhz;ezxa*;pi8jovm8 lp7t8; sect's nervous sysph8pb 8vo;;;mnl(xz*nzij7 e t z w2a8tem.



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 :k9p0bw 8 ;ndyhzo)- wo8j apya 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 compounds that are widely usei/s wt;k0eyk;t 60 hand as pesticides. However, there are concerns about their effect on honey bee0 ;skn yett0/i; a6kwhs 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, u5og4hf ;xg z9md 48q5k rka0 vcda;xcu-b/x time during an action potential. Which letter represents the segment of the action potential when voltage-gated sodium channels 40d u;v9 kx k/aug8 c;gz5a5cqbdfxxomr4,h- are open and voltage-gated potassium channels are closed?

  Which two features are more cwv ddkh+97nrj/bx dy qev)t l8b3122abundant per unit length in a non-myelinated neuron tbdh vqjr)+e38c t /dxnk9vbdy2l127 whan in a myelinated neuron?

  Which of the following is a/are correct descriptiosb9( g6fotq4 en(s) of the relative speed impulses are conducted at? e qo(64sfgb 9t
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 vnbc;m2xee 5ro l-,y8 occurs in the membranes of neurons during a stage of the action potential.bo xmly,5n; -revec82 What process does the diagram depict?

  The image shows neurons that are found in dog brains. What does letter 0;nkfot)c gy,g +k 01wifzt7zX indicate? +)zfgt0n ;ock g,wtf0zk7i 1y

  The diagram shows two neurons of equal length and diameter. Which neuron 71rvz,wlqi 10)++19dux e h s rbdtzkzwill transfer az9zd,lq+u)x ir+11s7 0bd 1 ehtv zrwkn electrical impulse faster?

  Which triggers the release of neurotransmitters from thnna knb-6n(e2 e presynaptic membrane?

  Which mode of transport do neurotransmitters use to travel across a synapsn sz8 +xx(vqrl4i35vdcmk /*j7 8 tkcje?

  Which statement explaine:sgbln3 ur) p*b7j3m3kp qm8 s why a nerve impulse is electrical?

1.Explain why a restins9 z,h5a f0v8vkx* awac4 oemgxk(c72g potential 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.