What happens if the threshold potential is not reached 7 co zxua-yn4j:3v5id ?

  At what membrane potential do voltagulgcu+ 1k:i1y e-gated sodium channels open?

  The diagram shows a pj7:p2e rpv;ecys3 ,x :bp / k3fju7utneuron.
Which arrow indicates a dendrite?

  How do neonicotinoid pesticide sd,q, 4hm9csds work?

  The diagram shows an action potentialjly hw4 /ytb5;.

What is happening at point X?

  Which is the correct definition of salta.) tihs;asp*f tory conduction?

Neuronal cells have special membrane properties oyxlcyrqr5uz7p.0z) bkl4x s5()i 9 ythat allow their axons to propagate action potential from one cell to another. The diagram below shows a xr s 57 krz9yi04yup y(o .5)cbqllz)xportion 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 neurotransmitters at q6ht;n dty9g ah30:cj8soq s/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 maintain a neuron’s resti8-acn+l g nku0kg*;thc r)5ckng potential?

  What is not a function of the myelin sheath?

Explain how the resting potential is maintained in a neuronl8zvwi-o, c24 fne.dw.

The diagram represents a synaptic cleft between two n gr qs92yn0m21dqdgo0 eurons in an insect's nervous system. 002ysod q qgm1d9ngr2



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 typh45gu -t3vcb9oq ;lzjical 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 ar e3,aa*;)jar f ehnz xg)d1r1ce widely used as pesticides. However, there are concerns about their effect on honey bees n1 reja,x zr )gd *fa;3)hea1cand 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 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 potential. Whinqn8 .4 wv a.1c*fje2-gqj wzich letter represents the segment of the action potential when voltage-gated sodium channels are open and volta ..ncwzqi4jv8g qjea nf* -12wge-gated potassium channels are closed?

  Which two features are more abundant per unit lengthqu**nqu6 mn-f rka(n ; in a non-myelinated neuron than in uuk * qa*n;nqrmnf-6(a myelinated neuron?

  Which of the following is a/are correct description(s) of the 9zp hk:qlz) *yt i0oj8relative speed impuzk*09qzjpyh :o i8t)llses are 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 o+v g9agtgp l:kvw jr6 j9jw;5-ccurs in the membranes of neurons during a stage of the action potential. What propvj k tgrjg;- 9gjvl6+w9wa:5cess does the diagram depict?

  The image shows neurons that are found in dog brains. w msxo (:b25b)os 7mdhi50tsl What does letter X indicate? 5bi)7bs0o:wd5o x(ssm lm ht2

  The diagram shows two ic-od *t6rs5jlj5jd1 neurons of equal length and diameter. Which neuron will transfer an eldtj5orclj1 i6dsj- *5ectrical impulse faster?

  Which triggers the releas+ay x.q mi:+f::a wjnte of neurotransmitters from the presynaptic membrane?

  Which mode of transport do neurotransmpci8z v-3qo4bx )w* xa 9m2ombitters use to travel across a synapse?

  Which statement explains why a nerve impulse io7i sgd. /3odxs electrical?

1.Explain why a resting potential ishl w t,y5/p3ztpg d(7u 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.