What happens if the threshold potential is not reachey m*om a08q7jed ?

  At what membrane potential do voltage-gated sodium channels open?s+dsr9j fphh2 *fdrlf:k 2;r:

  The diagram shows a neuro7eo,f3c(d4s ,rbacrqrhj : -d n.
Which arrow indicates a dendrite?

  How do neonicotinoid pesticides wc5-nff u qntj1ui.ror9e7 0 .l (b;xaeork?

  The diagram shows an action pltei9ww 4utl xt6pyj p+n;r.j .7d -(kotential.

What is happening at point X?

  Which is the correct definition of saltatory conduction?h6txa /o x7uux+7zg2wr.4 mgjm-cg:v

Neuronal cells have special membrf*k4l( ngv(1 )pf7lhcp+zgqqj0iqq + ane properties that allow their axons to propagate action potential from one cell to anotherpq+gz+)gq*qq4lpf(7lcf 0( i1kh j nv. 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 neuro.u1y*n q 4 daarn1ac4hj(9hortransmitters 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 mainti3,67 qoi5 xarl, nqqs8m 2i+i* fyi4sqvobe.ain a neuron’s resting potential?

  What is not a function of the myelin sheath?

Explain how the resting potential is maintained in a jgpgd:6ht ssf3+qme40)*cf9g hiqp0 neuron.

The diagram represents a synapticqnc o-jk3ao3fp1ox0bz -pq- 7 cleft between two neurons in an insect's nervousq13o nfb a-k-popjcx03z -7 oq 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 the ezl6zd8qk e+4j a 61czstructure 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 that are widely used as pesticides;n 58ym 0ekljs. 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 iymje0l5nks8 ;nstinct (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 p-qqiw mk5l7b. otential. Which letter represents the segment of the action potential when voltage-gated sodiumikw q5b7l -.qm channels are open and voltage-gated potassium channels are closed?

  Which two features are more abundant per unit length in a non-m1:.;,wqgit ipohb b 0zyelinated neuron than in a myeliwg,z;i :q 0bt1obp ih.nated neuron?

  Which of the following is a/are correct description(s) of the relative spkpiw k:rx9qyzdso2 )/2yd. 3i g .key-eed impulses are conducted at?w)kx9ky3pory 2. s/:yz2ie gqdi dk-.
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 the membranes of neuronay4.gn)u uey csvj *(2s during a stage of the (auvy2g )u4ejcn.s y*action potential. What process does the diagram depict?

  The image shows neurons r6*)4uh ujzdithat are found in dog brains. What does letter X indicatedhu* 4ir6j)z u?

  The diagram shows two neurons of equal length and diameter. Whichuytk4 3hjxbq67 8 jxo3t+, rkjw55iqd neuron will transfer ajqh wq5xd+7urti8j3kob,36yj4tkx 5 n electrical impulse faster?

  Which triggers the release of neurotransmitters from the pn qh;+dak9r d ge+2ng.v2u1rb resynaptic membrane?

  Which mode of transport do at4j -ziz mg)*neurotransmitters use to travel across a synapse?

  Which statement explains why a nerve impulse is elect;9 w7,u 5* gmmlop4wni ucnh ikdv85z1rical?

1.Explain why a resting potential isujdvj5 ldno yst/9y3( p-5+ sb 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.