What happens if the td 2+mwnmpf-9ecb/d5p hreshold potential is not reached ?

  At what membrane pot ssv6xi.vc 8*lential do voltage-gated sodium channels open?

  The diagram shows a neuroncth0h*h zq,9ud f( ;xk tgu ))/qqx0wc.
Which arrow indicates a dendrite?

  How do neonicotinoid pestifyf pq((83 cbccides work?

  The diagram shows an e25t1ja65x* ciqd(l vekwg/j action potential.

What is happening at point X?

  Which is the correct definition of saltatkoy7r xivm2 kwr(:( x0ory conduction?

Neuronal cells have specia lltdagz0 uhbp/4// n-l membrane properties that allow their axons to propagate action potential fr0d-gl/ 4ztuh/lpanb /om 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 exocyv.x wq8 p+iai:c1x( kvtosis of neurotransmitters 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 maint9g3.cwuz46p0h snsrctc vo;4ain a neuron’s resting potential?

  What is not a function of the myelin sheath?

Explain how the resting potential isz0ercc/tyy j2mi9sz)p dgg(x -0 s42, hy4bsv maintained in a neuron.

The diagram represents a synaptic cleft between two neurons in an ins yveu8 l,0gg.tect's nervous system. 8g,yvlu.e 0tg



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 struct 7,-* .cknhnw facgtr+ure 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 synthet-e)nf xs(qq n0ic compounds 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 and Clothianidin, and the effectn)0f-xe n (sqq 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 membray /, gra;3pegs*de8am,);+zk wi m-a(u dvhcfne voltage over time during an action potential. Which letter represents the segment of the action potential when voltage-gated sodium channels areykue em, -d;fw;va3*g 8zhi(m) dcra s,pag/+ open and voltage-gated potassium channels are closed?

  Which two features are 8 c c 9gwfb,y80 aa,slo4p1exxmore abundant per unit length in a non-myelinated neuron than in a myelinx0ca89 ac bl84fw,syex1, p ogated neuron?

  Which of the following is a/are correct description(s) of the relative sp;mds:w3 zi,bt8uj-r8 f tpco. eed impulses are condus3 : ipj88owb-dz . r,ftctu;mcted 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 thatl7.w)0+tk x1kp 4a bqmglj) my occurs in the membranes of neurons during a stage of the action potential. What process doxqa0mmg lk4bt j71p wy. )+kl)es the diagram depict?

  The image shows neurons that are fou zr0.3n ihv/awnd in dog brains. What does letter X indicate? vi rz .nwah0/3

  The diagram shows two neurons of equal length and diameter. Which n7jquj e2oe9 fjp3i6k v7-epi nugo71+fs.ji1euron will transfer an electrical impulsj1q76eejj-7j+23 7uv pu fpeo sfni1.i ogki9e faster?

  Which triggers the relek0hrrec7: /,b 7ypqeoase of neurotransmitters from the presynaptic membrane?

  Which mode of transport do neurotransmitters o6j8( be qx(g mqlhk(6use to travel across a synapse?

  Which statement explailh*u6bd b7oml6x w8f0 j6:ifins why a nerve impulse is electrical?

1.Explain why a resting potential is negativx 8 *k *bd)zx2vo;fmsve.
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.