What happens if the threshold potential is not reachedu0;o:eb)y(i hb y z 1tz*r4pp(eud3ap ?

  At what membrane potential do voltage-gated sodium channels open? l-fakz.9q7ad cup /4j

  The diagram shows a neuro b7 )l0ypom.lan.
Which arrow indicates a dendrite?

  How do neonicotinoid pesticides worw;u xd* 4gdch8;yrv w2k?

  The diagram shows an action pk9f xe4j;cwk:fzhz78 js p2jt)zi* 7qotential.

What is happening at point X?

  Which is the correct definition of saltato8m p z5zot2yf8ry conduction?

Neuronal cells have special membrane properties that allow their axons to p*)0 krc vj4h)t 8fedytecetf l1)r 15fropagate action potential fromfd)cf*ecrtf110y)h 4jr k ev5l8et)t 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 neurotransmitters7z ie ,q6scd sj(+b8gj 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 factorsbm4*1 7-oz1dx*(s 6jegbnv6xesw wp o that maintain a neuron’s resting potential?

  What is not a function of the myelin sheath?

Explain how the resting potential is maintainbz)oqmey-9 )n3, vy4 sp xcb:ied in a neuron.

The diagram represents a synaptic cleft between two neurons in an inhcm*g s1x+d84 j8h ns)wl11 9z 7mefco hge8hesect's nervous syst+em1ncwdg o 1xs)hlj7zh8es1f 8ec*8mhh94gem.



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 typkq 2uvz qz*roee:7:8o ical 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 pe( jyt-sto*ik (yke4 1hsticides. 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-let*iyosk1y -( ( t4tjhekhal 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 vod0bmgj9 qc+w- ri4bp-ltage over time during an action potential. Which letter represents the segment of the action potential when voltage-gated sodium channels are open and voltage-gated potassiupw 4c+djqi0rm b--9b gm channels are closed?

  Which two features are more abundant ro fux5m.s+7b per unit length in a non-myelinated neuron than in a myelinated u rm7.bo5fx+s neuron?

  Which of the following is a/are correct description(s) of the8hs-l6; t4 cin5okagim8ce/ f relative speed impulsegs/lo4kcah 5; if6 e8cnt8 mi-s are 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 neurons during a starx r7cwg545xafp y q((ge of the action potential. What process does(xf5p(wqa45c7g yxrr the diagram depict?

  The image shows neurons that sjru s,9kf*h, u:up,m are found in dog brains. What does letter X indicate fh*jkmr,u u,s:u 9ps,?

  The diagram shows two neurons of equal length andvg(:+pzw;m+6 cd ybo va*,hpe diameter. Which neuron will transfer an electrical impulse faster? dc ;zh +b a:p gw*pyv,m(e6+ov

  Which triggers the release of neurotransmitters njt w, wy2vp+4from the presynaptic membrane?

  Which mode of transport do neurotransmittu 1 ma jw5b5yxevu+ 9uubb*b:r p.1wq1ers use to travel across a synapse?

  Which statement expl sag25oky 9k5rains why a nerve impulse is electrical?

1.Explain why a resting potent9b24ri3z rjwssr aw 68.1co kiial 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.