What happens if the threshold potential is not rea:fsl )is3sn;9bive3d ;f)d r;b q bl*gched ?

  At what membrane potential do voltaqobc67 (j xue :zjc+b,ge-gated sodium channels open?

  The diagram shows a np 2 n*sjx* +,z)9wyh wzgg2mybeuron.
Which arrow indicates a dendrite?

  How do neonicotinoidpw.b6c4 t i g10gtd*td pesticides work?

  The diagram shows an actyt9p- f1cr2mnq:(.sx et*sul ion potential.

What is happening at point X?

  Which is the correct definition of sz su6 vbz9crv z5..smd2y9;eealtatory conduction?

Neuronal cells have special membrane properties that allow their axons to propag+qd4qdnod:o-2 8wwlp ate action potential from one cell to another. The diagram below shows a portion of anl dpwqdqodwo2 +48-: n 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 membrane?6i3az a.eccv3b27: n78muqf6 xwgl dg 5djps2
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 r fiymy l7(rih27 mbi/9esting potential?

  What is not a function of the myelin sheath?

Explain how the resting potential is maintained in a neurosi5(uy 8dn)vd dkmkl0c4 2h*in.

The diagram represents a synaptic cleft between two :; b il 24ef5sx3lilhmneurons in an insect's nervous s 3lh 2el;ifbi:ml45 xsystem.



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 structu unka .:3ze7wm8gbh0v re 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 compounds tha;;d nl6k:)dn ujby *wq9un5o ht are widely used as pesticides. However, there are concerns about their effect on honey bees and other pollinating insects. Tjdd:5uql b;h6*y kn)ou9n;wnhe 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 time during an action potentialil.kl v1m5v.x k jt j90:u,xpg. Which letter represents the segment of the action potential when voltage-gated sodium channels are open and voltage-gated pot .m5k 1 u9kjxv l,xi0p:g.lvjtassium channels are closed?

  Which two features are more abundant per unit lae1h79d 7smmf c82qki ength in a non-myelinated neuron i8cqeams7k719h d 2m fthan in a myelinated neuron?

  Which of the following is a/are correct descrizqn folkkop -. 8*n-1aption(s) of the relative speed impulsespf ona-nzqo1l k-.8*k 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 processw 08aagm cxs:e5.ihd /s8g d7b that occurs in the membranes of neurons during a stage of the action potential. What processs58e/g: xg.sb08c iddaaw 7h m does the diagram depict?

  The image shows neuruo /nn mnuebyg;0 +31sons that are found in dog brains. What does letter X indicate? o 30bnn gu yms1+n/eu;

  The diagram shows two ne ieb,6d nv6ct-urons of equal length and diameter. Which neuron will transfer an electrical im 6den v6ti-cb,pulse faster?

  Which triggers the release of neurotransmitters from the presynaptic mebqqt/uj p+:3wj1 /t-ooumgu)mbrane?

  Which mode of transport do neurodyl(:ywi k/b 9transmitters use to travel across a synapse?

  Which statement explains why a nerve impulse t s-,7gnxan a:*: ynvais electrical?

1.Explain why a resting potential r gy:/ohy 5 (ydnb9hd,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.