What happens if the threshodk5ngrktl)g 8xj.k f53tg68z ld potential is not reached ?

  At what membrane potential do voltage-gated sodium channels opentv7 x;( zjqyza8 * pt)25zcrwc?

  The diagram shows a neurof v1ex0r/qw1m n.
Which arrow indicates a dendrite?

  How do neonicotinoid7 y:z brb3mwl805+xu9 xvxy eg pesticides work?

  The diagram shows an action potentkj;we.z5oe-m ial.

What is happening at point X?

  Which is the correct 2s)km (a-h v7ss 3zj i5i8rkstdefinition of saltatory conduction?

Neuronal cells have special membrane properties that allow their axons to pr/nexghm /cyk*xt w-(w is/+j-opagate action potential from one cell to anothy*txnc +/ j(x-k hig-/w /smewer. 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 neurotransmitelq5jxk+8 ,ltters 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 mai7e7y8cw +sj8da ri d7ontain a neuron’s resting potential?

  What is not a function of the myelin sheath?

Explain how the resting potentiav;dal0;v gt9 3ju 7sqal is maintained in a neuron.

The diagram represents a synaptic cleft 6jes/ .fh k 5mqme1eo,between two neurons in an insect's nervous smfe sqem. hok/ 65,1jeystem.



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 t3.gcrz:hijg53ugyw3 3p0 0 s9z5ae4 cw wkcxdypical 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 as pesxdxu ; n/j eg8;lzzh/6ticides. However, there are concerns about their effect on honey bees and other p8nd 6x h/g/l;;ezzxju ollinating 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 ov9tw1seze. /u b vd -dxff00jo+er time during an action potential. Which letter represents the segment of the action potenbzfo0j1ex+9-/ tsfd du .w 0vetial when voltage-gated sodium channels are open and voltage-gated potassium channels are closed?

  Which two features are more abundant per unit le:az0+ ,cf3jh3p qgtpbczw x7;v0oj )lngth in a non-myelinated neuron than jcpv qf)opjwga 3 c3 +htx0;0l7:,zzbin a myelinated neuron?

  Which of the following is a/are correct description(s) of the relatxc+ 98kyit1g62v/ w xnsq-z r*azaq)w ive speed impulses areqy-rg9x6v1+aa8inq kwzs)2 c*w tz/ x conducted 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 neuronsid l. ie;uub)pv/wo;7h( s,:pm0lwdk during a stage of the action potential.mwdd(, os7 pk) /0w;b ihillu ;.pvu:e What process does the diagram depict?

  The image shows neurons that are found in dog brains. What does lette0dhwcq sn :):rtas3f0r X indicate? f0w::3sqtha 0cnrs )d

  The diagram shows two neurons of equal lengt9owud7f 2x9ua yoa0/dh and diameter. Which neuron will trans9o do9ayf 0a/wud2xu7 fer an electrical impulse faster?

  Which triggers the rele, bz.3ga0yj6p9o7z*jf fqozlase of neurotransmitters from the presynaptic membrane?

  Which mode of transport do neurotransmitters use to travel across a s8u trebhdux,h,h3: 9b ynapse?

  Which statement explains why a; p;zeto do.:xoh(q*f nerve impulse is electrical?

1.Explain why a resting potential is negat.jdng9bm /j :sive.
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.