Essential Biology 6.5 Nerves, Hormones, Homeostasis
Student Name:
1. Define the following:
Central nervous system
Peripheral nervous system
Neuron
Synapse
Neurotransmitter
Resting potential
Action potential
Due Date:
Candidate Number:
The brain and spinal cord.
2. State the name and function of each of the labeled structures of this motor neuron.
A = Dendrite
Function:
B=
Function:
C=
Function:
D=
Function:
E=
Function: speeds up propagation of action potential and saves energy
F=
Function:
Ms. Fargo
Stephen Taylor
Bandung International School
Essential Biology 6.5 Nerves, Hormones, Homeostasis
Due Date:
Candidate Number:
Student Name:
3. This diagram shows a simple reflex arc.
Identify the structures labeled A-D and state the actions 1-3.
A
B
C
D
1
2
3
4. Resting potential is the electrical potential across the membrane of a neuron that is not
conducting an impulse. It is used to repolarize (reset) a neuron in between impulses.
a. List two ions used in neurons.
b. Define electrical potential
c. State the specific method of membrane transport used to maintain resting potential
d. Explain how a resting potential is maintained, including why it is negative.
 Sodium ions are pumped out of the neuron
 By




Ms. Fargo
Stephen Taylor
Bandung International School
Essential Biology 6.5 Nerves, Hormones, Homeostasis
Due Date:
Candidate Number:
Student Name:
5. Action potential (AP) is the depolarization and repolarization of the neuron to conduct an
electrical impulse.
a. Use the following cues to explain how an AP is transmitted along the neuron.
Resting potential
Is maintained through...
Depolarisation
Is trigged by…
Which causes
Voltage-gated Na+ channels
“all or nothing response”
K+ channels
Refractory period
b. Explain the significance of the labeled features of this graph, showing an action potential.
1
2
3
4
5
c. Outline how a one-way direction of nerve impulse is maintained.
d. Compare resting potential and action potentials.
Also known as…
Internal potential is… (positive/ negative)
Sodium ions are…
Potassium ions are…
Membrane proteins used
(voltage-gated sodium channels or sodium potassium pump?)
Ms. Fargo
Stephen Taylor
Bandung International School
Resting potential
Action potential
-polarisation
- polarisation
Essential Biology 6.5 Nerves, Hormones, Homeostasis
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6. A synapse is a junction between neurons. This is a small gap between the terminal end of the
pre-synaptic neuron and the dendritic end of the post-synaptic neuron. The electrical signal of
the action potential is converted to a chemical signal, which passes across the synapse and
stimulates an action potential in the post-synaptic neuron. Whew.
a. Label these features of the synapse.
A
B
C
D
E
F
G
H
b. Explain the process of synaptic transmission, referring to all of the labeled structures above.
 AP reaches terminal end of pre-synaptic neuron
 This causes voltage-gated Ca2+ channels to open






c. Explain the need for high numbers of mitochondria in the pre-synaptic neuron.
d. Predict the effect of a drug which acts as a competitive inhibitor of a neurotransmitter.
Ms. Fargo
Stephen Taylor
Bandung International School
Essential Biology 6.5 Nerves, Hormones, Homeostasis
Student Name:
Due Date:
Candidate Number:
7. Define the following.
Endocrine system
Hormone
Gland
Target cell
Homeostasis
Negative feedback
8. State the function of the following hormones
Insulin
Glucagon
Adrenalin
Testosterone
FSH
LH
Oestrogen
Progesterone
HCG
Oxytocin
9. List five internal conditions in the human body maintained through homeostasis.
10. Explain how homeostasis is based on a system of negative feedback control.
Ms. Fargo
Stephen Taylor
Bandung International School
Essential Biology 6.5 Nerves, Hormones, Homeostasis
Student Name:
Due Date:
Candidate Number:
11. Complete the flow chart below to show how the hypothalamus controls body temperature
through hormones. What are the body’s responses?
12. Blood glucose levels are maintained by hormones produced in the pancreas.
Complete the table to show glucoregulation.
High Blood Sugar
Pancreatic cells used
Low Blood Sugar
Beta cells
…which secrete…
… carried in blood to….
&
… causing conversion of..
… to …
Overall effect:
Ms. Fargo
Stephen Taylor
Glucose removed from blood
Bandung International School
Glucose released into blood
Essential Biology 6.5 Nerves, Hormones, Homeostasis
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13. Diabetes mellitus is a disease in which regulation of blood glucose is difficult.
Distinguish between type I and type II diabetes.
Type I
Type II
Cause
Effect
Risk factors
Treatment
14. Explain how we can tell from this table that the patient is diabetic.
15. Distinguish between nerves and hormones.
Nerves
Route
Direct from coordinator to effector
Hormones
Through:
From:
To:
Signal type
Chemical
Time to take action
longer
Duration of effects
16. Identify the part of the brain are nerve impulses converted to hormonal signals.
Ms. Fargo
Stephen Taylor
Bandung International School
Essential Biology 6.5 Nerves, Hormones, Homeostasis
Due Date:
Candidate Number:
Student Name:
17. Complete the steps below to show how the nervous and endocrine systems work together to
regulate body temperature.
Stimulus
Sensory neuron
Relay
Effector
Hormone 1
Gland
Target cells
Effect
Release of Thyroid hormone
Target cells
Effect
Data-based question practice, from the QuestionBank CDRom
18. The sense of taste is normally caused by the stimulation of chemoreceptors in the taste
buds of the tongue. There are four main 'tastes': sweet, salty, bitter and sour. The tongue
also has receptors for temperature. It is known that the taste of food can vary according
to whether it is cold, warm or hot. Scientists discovered that just warming or cooling parts
of the tongue, even when no food was present, also caused a sensation of taste.
Scientists experimented with a group of people. They gradually cooled the tips of their
tongues and measured the intensity of the taste felt by each member of the group. The
experiment was repeated, this time warming the tip of the tongue. The graphs show the
average values for the group.
Ms. Fargo
Stephen Taylor
Bandung International School
Essential Biology 6.5 Nerves, Hormones, Homeostasis
Due Date:
Candidate Number:
Student Name:
Cooling the tongue tip
Warming the tongue tip
Taste intensity felt
/ arbitrary units
moderate
weak
just
detectable
35 25 35 20 35 15 35 10 35 5 20 25
Decrease in temperature from 35 ºC
Key:
Salty
Bitter
20 30
20 35
20 40
Increase in temperature from 20 ºC
Sweet
Sour
[Source: modified from Cruz and Green, Nature (2003) 403, page 889]
(a)
Identify which taste was felt most strongly when the tip of the tongue was
(i)
cooled:
(ii)
warmed:
(1)
(b)
Compare the effects on the taste of sweetness, of warming and cooling the tip of the
tongue.
(2)
(c)
It is important that such experiments use a population sample that is representative.
Suggest two biological criteria the scientists would have used to select the people to
be tested.
(1)
Ms. Fargo
Stephen Taylor
Bandung International School
Essential Biology 6.5 Nerves, Hormones, Homeostasis
Due Date:
Candidate Number:
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(d)
Explain whether cooling or warming the tip of the tongue has the greater effect on
the sensation of taste.
(2)
The scientists discovered that there were two types of chemoreceptor in the tongue tip.
They called these A and B. They tested these chemoreceptors using solutions of sucrose to
find out the type of taste and the intensity felt. The results are shown in the bar chart.
moderate
weak
Taste intensity felt
/ arbitrary units
just detectable
sweet detected
Key:
(e)
sour detected
A
B
Compare the effects of sucrose on the A and B chemoreceptors by giving two
similarities and two differences.
Similarities


Differences


(4)
(Total 10 marks)
Ms. Fargo
Stephen Taylor
Bandung International School
Essential Biology 6.5 Nerves, Hormones, Homeostasis
Due Date:
Candidate Number:
Student Name:
Works Cited
1. Taylor, Stephen. Nerves, Hormones and Homeostasis (presentation). Science Video Resources.
[Online] Wordpress, 2010. http://sciencevideos.wordpress.com/bis-ib-diploma-programme-biology/06human-health-physiology/nerves-hormones-homeostasis/.
2. Allott, Andrew. IB Study Guide: Biology for the IB Diploma. s.l. : Oxford University Press, 2007. 978-019-915143-1.
3. Mindorff, D and Allott, A. Biology Course Companion. Oxford : Oxford University Press, 2007. 978099151240.
4. Clegg, CJ. Biology for the IB Diploma. London : Hodder Murray, 2007. 978-0340926529.
5. Campbell N., Reece J., Taylor M., Simon. E. Biology Concepts and Connections. San Fransisco :
Pearson Benjamin Cummings, 2006. 0-8053-7160-5.
6. Burrell, John. Click4Biology. [Online] 2010. http://click4biology.info/.
7. IBO. Biology Subject Guide. [Online] 2007. http://xmltwo.ibo.org/publications/migrated/productionapp2.ibo.org/publication/7/part/2/chapter/1.html.
Self Assessment:
Essential Biology
Criterion
Presentation &
Organisation
Academic
Honesty
Objective 1
understanding
Objective 2
understanding
Objective3
understanding
Logic, notation,
mathematical
working
Further research
Assessment
Complete (2)
Partially complete (1)
NA
Complete and neat. All command terms
highlighted, tables and diagrams well presented.
Sources cited using the CSE (ISO 690 numerical)
method, with Works Cited section complete and
correct.
All answers for the following command terms
Most answers for the following command terms
correct:
correct:
Define
Draw
Label
List
Measure State
Most answers for the following command terms
All answers for the following command terms correct:
correct:
Annotate Apply
Calculate Describe Distinguish Estimate Identify
Outline
Most answers for the following command terms
All answers for the following command terms correct:
correct:
Analyse Comment Compare Construct Deduce Derive Design Determine Discuss
Evaluate
Explain Predict
Show Solve
Sketch Suggest
Answers are presented in a logical and concise
manner. SI units used most times, with correct
NA
unit symbols and definitions of terms. All
mathematical working shown.
Evidence is apparent of research and reading
beyond the textbook and presentations to find
correct answers to challenging questions. If any
NA
questions are unanswered, this criterion scores
zero.
NA
Total (max 10):
Ms. Fargo
Stephen Taylor
Bandung International School
Self
MrT
Essential Biology 6.5 Nerves, Hormones, Homeostasis
Student Name:
Ms. Fargo
Stephen Taylor
Bandung International School
Due Date:
Candidate Number: