What happens if the threshold potti0ukhs0n:5n l t6g5 nential is not reached ?

  At what membrane potential do voltage-gated sodiumga(y. /)brcy5jqd .+o;i t yzo channels open?

  The diagram shows a neur/) .5pf/o/v dcezebuxng 9z1/xl/lavon.
Which arrow indicates a dendrite?

  How do neonicotinoid 8w9t+8eme kkb 8vem +gpesticides work?

  The diagram shows an actions622b e1yyuy u potential.

What is happening at point X?

  Which is the correct definition of saltatoryx p dqz*nv,ma8q42aj: conduction?

Neuronal cells have special membran9 ot s7bcaqw50e properties that allow their axons to propagate action potential from ones7w5 0ot9bca q 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 exocytosis of neurotransmittercp(va7 ,n axy ujs5(h2s 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 factoxbta33r sfddvy* ; (s3rs that maintain a neuron’s resting potential?

  What is not a function of the myelin sheath?

Explain how the resting pohua f.era32i(yo ao*0tential is maintained in a neuron.

The diagram represents a synaptic 9o5 ps+mku k4acleft between two neurons in an insect's nervous sy+ku5 om4a 9pksstem.



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 ty fojc*q5yk)u/ pical 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 synthlpme6 kyhs +dljpa7 69evm7 +0etic 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 effect it had on their homing instinct (ability toy 7+lp+l7e60m9phvedjkm 6 sa 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 a8)bg 32 rnb (bir jb2k389mx9lnbn urin action potential. Which letter represents the segment of the action potential when voltage-gated sodium channels are open and voltage-gated potbr889nb9ik) b3u gi m3(nnx2rbrl 2bjassium channels are closed?

  Which two features are more abundant per unit l; f6qn5 p0w63a-us:lanfcmk yength in a non-myelinated neuron than in a myelinatuq :p0ycnl6m6sf- akw;f an35ed neuron?

  Which of the following is a/are correc.b,i jsvd6gcfh(i njr27w f 2xy7q/w od+tp (6t description(s) of the relative speed impulses arerdi72j(x2/6p yt,iqsbg f.w +6ohdw jn 7cvf( 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 that occurryuu(:.,qwwz *1v, hz5vb*yqd xrvf; s in the membranes of neurons during a stage of the action potential. What process does v*1.bdxuzfz;v*(vyh r,qw,:u rw5 qy the diagram depict?

  The image shows neurons that are found in nalm -l8lu,ow p6f(n gg)9zo ,du)l4b dog brains. What does letter X indicateu()6 8oonf4lbg) g-l,zdaml unp 9wl,?

  The diagram shows two neurons of equal lengdu sxzq(c3s2wz19.3ffn6 mz p 4fzh+sth and diameter. Which neuron will tr 4su21n3fhf3(s+ dqzc z. z pf9zmwxs6ansfer an electrical impulse faster?

  Which triggers the release of neurotransmitters od/i bz+exu/e6 (hzl /:ft*u bfrom the presynaptic membrane?

  Which mode of transport do neurotransmitters use to travel yeux) b6u9 o,z q)cleiv lk*(.across a synapse?

  Which statement explains why a nerl2rve) kcf. :eve impulse is electrical?

1.Explain why a resting potential is nej+im/jtxf 20 9j)0j 9yjo weokgative.
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.