What happens if the threshold potential e /4s yjl 8mp4t(vhc1qgq5 r9ais not reached ?

  At what membrane potential do voltage-gated sodium ;n w)tfcc 2y7nchannels open?

  The diagram shows a n q:*op9k8/cpxq* att geuron.
Which arrow indicates a dendrite?

  How do neonicotinoid pesticidesp://zsw8 (li nk:8agunilhb( work?

  The diagram shows an actionr(cdep 6h.x ,j potential.

What is happening at point X?

  Which is the correct definition of saltatory conduaoll o(. 7zh4,b6pbvwction?

Neuronal cells have special membrane properties that allow their axons to propaio+d0 a3:m ifngate action potential from one cell to another. The diagram below shows a portion of an mi0 3 i:fond+aaxonal 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 neu4 *ghi vp2b f35f:cpwk-gzuw2h k/nn0 rotransmitters 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 m 34jm q0drcvxb) .yw8laintain a neuron’s resting potential?

  What is not a function of the myelin sheath?

Explain how the resting potential is m0j4v s d8lrk;r( h rydhbax25+aintained in a neuron.

The diagram represents a synaptic cleft between two neurons in an inssmj*kt/o)6 ymo2gm7v/xz0c b ect's nervous syste/ m26mb)g7s0oj/ *kto vz xcymm.



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 oqv;kph*ohhkph.n uer w,961 6f 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 compoun dw /ft;pvf4 jkp1q88hds 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) weh4p;jd t 8/f kvq81pwfre 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 dtd1 oumxk9* ) /sff1mvwa1+ tpuring an action potential. Which lettfdtvmm+kap 9uw/ft) o x1 s1*1er represents the segment of the action potential when voltage-gated sodium channels are open and voltage-gated potassium channels are closed?

  Which two features are more abundang+ vm48 h802 a1zievl*utpqc qt per unit length in a non-myelinated neuron than in a myelinated neurop8tl482mzq+i1aquc g*ehv v 0n?

  Which of the following is a/are correlvwu1ox zd(me/*l yutz 8 tjz,e,940n ct description(s) of the relative speed impulses ar1mdy,uo e8tz 0xln,l4(z/ 9jzt w*vuee 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 occurs 1fvvi+3;7ofkmqw0h bin the membranes of neurons during a stage of the action 13mvbwff;h iv+ o70kq potential. What process does the diagram depict?

  The image shows neurons that are found in dog brau5ts4fzf60 zf, l)exeins. What does letter X indicate? fu4xz0 l6e5,t fz)fs e

  The diagram shows two neurons of equal length mz9 zzqqm414a jn +uu dt/k1i3and diameter. Which neuron will transfer an electrical impulse faster? mumn14zz4 iq /a j+zktuq 9d13

  Which triggers the release of neurotransmitters from theu cuaor8-+ q)e presynaptic membrane?

  Which mode of transport do neurotransmitters use to tr yh:vews1d 30hsj 59ezavel across a synapse?

  Which statement explains why a nerve impulse is electufo:kgk 1h* h.m3r h/hrical?

1.Explain why a resting pote2fc 6dab7 (5aa fp/fzcntial 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.