What happens if the thresh4mmkgx b/6fevv nk)4 f+p-nsz4xdr0 5old potential is not reached ?

  At what membrane potential do voltage-gated sodium channels openu2gaod d-o+wqe+g35w 6 ) wxcx?

  The diagram shows a neuron. 8 k7:n k lfmj aoibr/959jwgp,
Which arrow indicates a dendrite?

  How do neonicotinoid pesticid5f-tc0*o8m zwkcpc y;es work?

  The diagram shows an act8sz:6vjj5/w exi)bption potential.

What is happening at point X?

  Which is the correct definition of saltatory con-yr: i* ii3(f2-el;ezxut1jeyyr l 9 hduction?

Neuronal cells have special membrane properties that allow their axons to propq. (en df*eo rq * :qa3bcctj8oq7zb5:agate action potential from one cell to another. Tqcq:nj:ce ozebr5q7bo*3 af d(tq*.8he 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.v wrd to((g -x-pyd(gydw,- xlduj., 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 facto9s tguj(a7oguo;wsoae 1(e;2vl c5d 0rs 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 neuro5* *ujsc7.l 2khxdbvo n.

The diagram represents a synaptic k+yj jq7ngto *d;3sk7w t*ln9cleft between two neurons in an insect's nervou7k *s w7;t9kjg y+ *3qjtolndns 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 thegu dn d+,z4;zh structure 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 synxf gh t:md,(g3thetic compounds that are widely used as pesticides. However, there are concerns about their effect on honey bees and other ,m fdgx3: ht(gpollinating 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 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 membrahht y1ofx : nn;16sl9xne voltage over time during an action potential. Which letter represents t; y soh9 l1h6:nnfxx1the segment of the action potential when voltage-gated sodium channels are open and voltage-gated potassium channels are closed?

  Which two features ak2- rdzbg . j. 1qnd*,geef0kex/ci ai(k7bq8re more abundant per unit length in a non-myelinated neuron than in a myelinated neudbj0ezir1 -xeq /bnk 7(gq g2k. ,8ef.kacdi*ron?

  Which of the following is a)lopbv28ax k9uz6g00 eu3 cr,oebf x7/are correct description(s) of the relative speed impulses ar c ao )u eg2xl7bkorp036,8bx0evuf9ze 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 thatvgceen7oq2256gg 3 4 c (fwsqv occurs in the membranes of neurons during a stage of the action potential. What process does the diagra7nqvc ows 3 4gv(2fqecg6e25gm depict?

  The image shows neurons that are found in dog brains. What does letter X indism ck 4xv 580n/3obagmflw2f;cat; nk/ fmwf52xs 3bvm8a0 4logce?

  The diagram shows two neurons of equal length and diameter. Whichvphz q/m x5k)ahb6r3 84rmi (b neuron will transfer an electrical impulse faste abr3/xh)mki4 6qh8rbv5m (zpr?

  Which triggers the release6fqgqb/a)g(8c6:cp*agcwr x of neurotransmitters from the presynaptic membrane?

  Which mode of transport do neurotransa,hy s0 (w11sp(xs8v3f6qrza7h s noymitters use to travel across a synapse?

  Which statement explains w+pgvzfvbj ) ) p8reb lf8w1:(ihy a nerve impulse is electrical?

1.Explain why a resting potential is w/rc)cj5k-u znegative.
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.