What happens if the threshold potential is not reasv8yhw.3g3 56y,lnhpd5 vc0f du9.g t thhg 3oched ?

  At what membrane potential dorvhz ;64i1alv voltage-gated sodium channels open?

  The diagram shows a neuronhrs(oqphf 2m; 8sie4re vq1.+.
Which arrow indicates a dendrite?

  How do neonicotinoid pesticides work? b5 jtkipcd 9:5w ayca09zn.u7

  The diagram shows an action potenti*rjibi;ec k296 :jthw al.

What is happening at point X?

  Which is the correct definitiox +mxcp( +ljh4n of saltatory conduction?

Neuronal cells have special memi e5z1;gq p/ocbrane properties that allow their axons to propagate action potential from one cell to another. The diagram below gc;q1 ezo p/i5shows 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 neurotransmitkjf4,l 7t 9aaw3/ +ms ryria1kters 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 fac /,xps o/, )6krwjnzdctors that maintain a neuron’s resting potential?

  What is not a function of the myelin sheath?

Explain how the resting potential is maintained in a neur+toi*mkgnu6 o7r hg )k 20bw:ion.

The diagram represents a synaptic66qks )u wdn/g cleft between two neurons in an insect's nervous systu6dwqks/g6 n )em.



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 typical neurkoz ;i)g;k;w c58tjo ion.
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 pdo9 n5r ig-o 5l ung4)/vns2rused 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 effect it had on their homing instinct (ability to fly back to their hivun-9n5i/n5rl gv)2s 4rogp doe).

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 mema dkgjj:* bq*41th5oebrane voltage over time during an action potential. Which letter represents the segj :o1*jbtqe 4gd*5ah kment of the action potential when voltage-gated sodium channels are open and voltage-gated potassium channels are closed?

  Which two features are more abundant per unit length in a non-myelinateu1 90ctqzget -d neuron thanc1 geq9u-ztt 0 in a myelinated neuron?

  Which of the following is a/are correca 4pffdh6b7i 0edll3a/lj b t:1pc 4)ct description(s) of the relative speed impulses are conducted at? 4/l4 : flj fp0b7)ddi hbl a6capt31ec
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 thetw4wo,b/ d 5vo membranes of neurons during a stage of the action potential. What proces/td,5o v4o wbws does the diagram depict?

  The image shows neurons that are found in dog brains. What does lett(c k30yun4 v j6jrg/6h+sy ister X indicati/nk js4s 6grt30 u6hy( y+jvce?

  The diagram shows two l qp047s(edhwneurons of equal length and diameter. Which neuron will transfer an electrical impulse faster qls4(wh0e 7pd?

  Which triggers the release of neurotransmitters from the pre0ar4xgl cl91 rb-p/mlsynaptic membrane?

  Which mode of transport do neurotransmitters use to travel acr/c e l0xwk*shh,p o(,soss a synapse?

  Which statement explains9 cz5+odfciowr 65 )nf why a nerve impulse is electrical?

1.Explain why a resting pot,ax:fmqd j-8j- bw,t aential 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.