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Page 1

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1. The pancreas contains endocrine tissue. The figure below shows an
electronmicrograph of a section of pancreatic endocrine tissue.

nucleus rough endoplasmic reticulum cell membrane beta cell secretory vesicle




alpha cell secretory vesicle mitochondrian x 30000


(a) Name the endocrine tissue shown in the figure.

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[1]




(b) Name the…

Page 2

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(c) During vigorous exercise, the blood glucose concentration falls.

Describe the changes that take place to make sure that the blood glucose
concentration does not fall to a dangerous level.

In your answer, you should use appropriate technical terms, spelled correctly.

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Page 3

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2. (a) Fig. 1 is a diagram of a neurone.

A B C D




direction
of impulse indicates
long distance

Fig. 1

Name the structures A and B.

A ......................................................................................................................

B ......................................................................................................................
[2]




JFS School 3

Page 4

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Fig. 2 shows a recording of the potential difference across the membrane of an axon as
an action potential is transmitted.

+40
+30
+20
+10
0
membrane ­10 X Y
potential / ­20
mV ­30
­40
­50
­60
­70
­80
­90
0 1 2 3 4 5
time / ms…

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The table below shows how the speed of conduction of an action potential varies with
the diameter of myelinated and non-myelinated axons in different organisms.

organism type of axon axon diameter / µm speed of conduction
/ ms-1
crab non-myelinated 30 5
squid non-myelinated 500 25
cat myelinated 20 100…

Page 6

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3. Fig.1 represents some of the changes that occur across the membrane of the axon.
Three protein complexes are shown to be present in the membrane:

· sodium channels

· potassium channels

· sodium-potassium pumps.

outside cell K+ K+
+ + + + + +
1
resting potential
­ ­…

Page 7

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Fig.2 shows the change of membrane potential associated with an action potential.


+40


membrane
potential / mV A
B

C
­65



0 1 2
time / milliseconds

Fig.2

(a) (i) State which of the three diagrams of the axon membrane in Fig. 1 match up
to the phases labelled in…

Page 8

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(ii) With reference to Fig. 1, explain the changes in membrane potential in
Fig. 2.

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[5]
[Total 6 marks]




4. In this question, one mark is available for the quality of spelling, punctuation and…

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Explain how action potentials are transmitted along a nonmyelinated neurone and
describe which parts of this process are different in myelinated neurones.

No credit will be given for reference to events at the synapse.

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Page 10

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5. Hummingbirds are very small. Typically their mass is between 3 and 5 g. They are able
to hover at a fixed point in the air by beating their wings very rapidly. The rufous
hummingbird, Selasphorus rufus, is a migratory species. It breeds in Canada and
Alaska in the summer,…

Comments

Ibzay101010

Do you happen to have any of the answers for these?

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