What happens if the threshold potentmr eb*e.+ q,b ss knyp*og:z+0ial is not reached ?

  At what membrane potential do voltage-gated sodium channels opanl qxfg7+ 6 9jwpk /+pzai90wen?

  The diagram shows a 7afplwdn 9( i:neuron.
Which arrow indicates a dendrite?

  How do neonicotinoid pesticides work8pd;:f oi.u7 cll 8i4 f3iqrkw/vq.yp?

  The diagram shows an action pothmomfvnp( z6n .ziimm-- xa)2i+ao2;ential.

What is happening at point X?

  Which is the correct dtotsfw(9, us 5efinition of saltatory conduction?

Neuronal cells have special membrane prop)vmjr:tkc 14 xerties that allow their axons to propagate action potential from one cell to another. The diagram below shows a pcm:v )jtrk1x4 ortion 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 neurotrans (-3by1pa w5 hsfr7zcxzlw5d6mitters 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 restin ujwd1w;2fxnge6;:b a g potential?

  What is not a function of the myelin sheath?

Explain how the resting potential is maintained ta9zxn31npt .r8or(q+j 4cc vin a neuron.

The diagram represents a synaptic clefe 30 pck;7tqa(1gb6 hzyex2cft between two neurons in an insect's nervog607cy1tax ezcf2h 3;bpkqe( us 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 structurh2y da0jjxd7b1f5 2 coe 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 synthetic co3 cv.yq ltl5k)mpounds 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 doses of two neonicotinoids, Imidacloprid )qyl 5cv3kl.t 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 showsoa7bml mck1jaj5,p567 9a4zmowen:kc 9gk .c membrane voltage over time during an action potential. Which letter represents the segment of the cpb mgke9km4cwa9c:6o77ojl5,jn a kz a5.m1 action potential when voltage-gated sodium channels are open and voltage-gated potassium channels are closed?

  Which two features are more abundant j6- qn 1kcz).me)py lhper unit length in a non-myelinated neuron than in a myelinl e. n)-mqy1h6zj)ckpated neuron?

  Which of the following is a/are correct description(s) of the relative speed 8d tove. 5x5 3oh5nsu/gu5fhmimpulses are conduu eo8sgo5h555thmxd/.3 v functed 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 tha( . zttb 0v8k:frtc:slt occurs in the membranes of neurons during a stage of the action potential. What process does th k0t: csvbtrtl: f(8z.e diagram depict?

  The image shows neurons mu-fw4 s/7 7ujai9 vehthat are found in dog brains. What does letter X indicate?4j fmeas7 iw-7u/ 9huv

  The diagram shows two neurons of equal length and dnj/o5i,auyk (iameter. Which neuron will transfer an electrical i jok yna/ui5,(mpulse faster?

  Which triggers the release of neurotransmitters from the presynaptic membrane?6am0nb v-b65e*oyw+8qy amec

  Which mode of transpor:up urhd5ds fc3a7 tz 7;o5z ji2dq+.gt do neurotransmitters use to travel across a synapse?

  Which statement explains why a nerve impulsew qixdho1b+t4bj; ixp 6me,08/d7 mcv is electrical?

1.Explain why a resting pot3w)rjauq)6 diential 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.