Name: _________________________________________________ Class/Period:_______________________________
IB Biology SL - Study Guide
Topic 6.1: Digestion
1.
2.
3.
4.
Define enzyme.
Define substrate.
Define macromolecule.
Explain why digestion of large food molecules is essential.
5.
Complete the table to show the substrate, product and enzyme of digestion of these food macromolecules:
Carbohydrates
Type of
Enzyme
Lipids (fats)
Proteins
amylase
Example of
enzyme
trypsin
Product(s)
Source of
enzyme
pancreas
Optimum pH
6.
7.
Where might one find an enzyme with an optimum pH of 2?
Outline how the following factors affect the rate of an enzyme-catalysed reaction:
a. Substrate concentration
b.
pH
8.
Explain the need for enzymes in digestion, with a focus on temperature and energy. A graph showing the difference
between a catalysed and uncatalysed reaction is useful.
9.
Digestion of large food molecules is through enzyme-assisted hydrolysis. Complete the equation below to show hydrolysis
of a dipeptide.
10. Draw and label a diagram of the human digestive system in the space below. Label the functions of the stomach, small
intestine, and large intestine.
11.
12.
13.
14.
15.
The stomach is extremely acidic. What is this acid?
What the function of this acid?
How does the stomach aid mechanical digestion?
Which enzyme is released by the stomach?
Much digestion and absorption occurs in the small intestine. How is the acidic chyme neutralized in the small intestine?
16. What feature of the ileum (small intestine) wall allows for greater absorption of food molecules?
17. In the space below, draw and label a single intestinal villus. Include epithelial cells, lacteal and capillaries. Explain the
significance of the structures of the villus in absorption of digested food molecules.
18. Distinguish between ingestion, digestion, absorption, assimilation, and excretion.
Ingestion
Digestion
Absorption
Assimilation
Excretion
19. Distinguish between the small and large intestines in terms of structure and function.
20. How can a high-fibre diet promote intestinal health?
Name: _________________________________________________ Class/Period:_______________________________
IB Biology SL - Study Guide
Topic 6.3: Defense against infection disease
1. Define pathogen.
2. Give named examples of the four types of pathogen.
3. List five methods by which pathogens can be transmitted.
4. Explain why antibiotics are not effective against viruses.
5. (AD) Outline the emergence of Multiple-Resistant bacteria as a result of overuse of antibiotics and subsequent
evolution by natural selection.
6. How do the skin and mucous membrane act as the body’s primary defense against infection?
7. What is the role of the following types of cells in defense against infectious diseases?
Phagocytes (macrophages)
B-cells
T-cells
8. Draw a diagram to show how a phagocyte engulfs a pathogen by phagocytosis. Be sure to label the role of
lysozymes in this process?
9. Distinguish between antigens and antibodies.
10. Annotate the diagram to explain how clonal selection leads to antibody production.
11. Define HIV.
12. Define AIDS.
13. Distinguish between HIV and AIDS.
14. Outline in a list of steps the effects of HIV on the immune system.
15. Discuss the cause, tranmission, and social/economic impacts of HIV.
16. How might HIV/AIDS affect devloped nations differently to developing nations such as regions of Africa?
Name: _________________________________________________ Class/Period:_______________________________
IB Biology SL - Study Guide
Topic 6.2: The transport system
1. Digested food molecules are carried in the blood around the body. Other than digested food molecules, what
other substances are transported in the blood?
2. What are the functions of the following components of blood:
Plasma
Platelets
Erythrocytes
Leukocytes
3. Draw and label a simple diagram of the heart showing:
Right and left atria and ventricles
Atrio-ventricular and semi-lunar valves
Aorta, Pulmonary artery and pulmonary vein, vena cava
Cardiac muscle
4. Where is the cardiac muscle thickest? Why?
5. Distinguish between oxygenated and deoxygenated blood.
6. Outline the journey of a single red blood cell taking one full circuit of the transport system, starting and finishing
at the liver. You could use a flow chart/cycle for this.
7. Why is the flow of blood described as double circulation?
8. What is a myocyte?
9. Explain the myogenic origin of the heartbeat.
10. Name and label the parts of the heart responsible for initiation and
propagation of the heart beat on the diagram to the right.
11. What is meant by the term indefatigable?
12. Complete a flow chart to show how heart rate changes with
exercise. Include the roles of the blood, medulla oblongata, nerves,
SA node and the Vagus nerve.
13. What is the effect of the hormone adrenalin?
14. Compare the structure and functions of these blood vessels:
Artery
Capillary
Vein
Diagram
(labeled, cross
section)
Function
Travels…
How is structure
related to function
for the blood
vessel?
From…
Through …
To …
Name: _________________________________________________ Class/Period:_______________________________
IB Biology SL - Study Guide
Topic 6.4: Gas exchange
1. Distinguish between ventilation, gas exchange and respiration. Use a chart if necessary.
2. Capillaries deliver deoxygenated blood to and carry oxygenated blood from the alveoli of the lungs. Draw a
simple diagram to show the flow of blood and gas exchange at the alveolus.
3. List 3 structural adaptations of alveoli suit them to their function of gas exchange.
1.
2.
3.
4. By which two methods is a concentration gradient of CO2/O2 maintained at the alveolus?
1.
2.
5. Draw and label a simple human ventilation system, including:
Mouth/nose, trachea
Bronchi, bronchioles, alveoli
Lungs, ribs, intercostal muscles and diaphragm
6. Control of ventilation rate, like the heart rate, is via the autonomic nervous system.
a. Under exercise, there is more CO2 in the blood. At which part of the brain is this increased CO2
detected?
b. What is the effect of this on breathing rate?
7. Complete the table below to show the events of ventilation (breathing):
Inhalation
Exhalation
Diaphragm
Abdominal muscles
relax
External intercostals
muscles
Internal intercostals
muscles
Lung Volume
Air pressure in lung
Movement of Air
increases
Name: _________________________________________________ Class/Period:_______________________________
IB Biology SL - Study Guide
Topic 6.5: Nerves PART 1
1.
Extend the organizational chart below to show some components of the central and peripheral nervous systems.
2.
Draw a simple diagram of a motor neuron (nerve cell), including the cell body, nucleus, dendrites, axon, terminal branches,
motor end plates, myelin sheaths, Nodes of Ranvier, and the direction of the nerve impulse.
3.
Describe the journey of a nerve impulse in the reflex arc, from the stimulus to the effector.
4.
Define resting potential and action potential.
5.
Complete the diagram below to show why the resting potential of a neuron is negative.
6.
Define depolarization and repolarization.
7.
Annotate the graph below to explain what is happening in each stage of an action potential (AP). Include the movement of
ions into and out of the cell and how this occurs.
8.
What is the importance of the refractory period in propagation of an action potential?
9.
What is the importance of these membrane proteins in nerve impulses?
Sodium-potassium pump
Sodium channel
Potassium channel
Name: _________________________________________________ Class/Period:_______________________________
IB Biology SL - Study Guide
Topic E.1: Stimulus and response
1. Define the following terms in the context of animal behavior:
Stimulus
Response
Reflex
2. In the space below, draw and label a diagram of a reflex arc for a pain withdrawal reflex. This should include the
spinal cord, spinal nerves, receptor cell, sensory neuron, relay neuron, motor neuron, effector, white/gray
matter, and ventral/dorsal roots. Explain the role of each!
3. In the notes online, there are MULTIPLE examples of animal responses that can be affected by natural selection.
You must be able to explain two of them. Pick two that you understand the best and OUTLINE them!
Name: _________________________________________________ Class/Period:_______________________________
IB Biology SL - Study Guide
Topic E.2: Perception of Stimuli
1. Complete the table below to outline four main types of receptors and the stimuli they detect:
Receptor
Stimulus
Examples
Mechanoreceptor
Pressure
Texture
Vibration
Touch, pain and tension in skin
Touch receptors in skin
Inner ear for hearing and balance
Thermoreceptor
Chemoreceptor
Photoreceptor
2. Label the structures of the human eye with their names and functions:
3. Label the section of the retina below:
4. Annotate the diagram below to outline how light stimulus is received by the photoreceptor and converted to an
action potential:
5. Compare rod and cone cells:
Rod cells
Cone cells
Light brightness
Diversity of cells
Wavelength sensitivity
Impulse: neuron ratio
distribution
6. Explain how visual stimuli are processed in the eye and brain, with reference to the following stages (you can
draw or find images to help, if you wish):
a. Image focusing and inversion in the cornea and retina
b. Visual fields
c. Contralateral processing and the role of the chiasma
d. The role and location of the visual cortex in the brain
e. Edge enhancement and ‘filling in’ of the blind spot
7. Label the diagram with the structures of the ear, and use the diagram to explain how sound is perceived by the
ear.
Name: _________________________________________________ Class/Period:_______________________________
IB Biology SL - Study Guide
Topic E.3: Innate and learned behavior
1. Distinguish between innate and learned behaviour:
Innate
Learned
Genetic (predetermined)
Basis/ foundation?
Based on experience
Modification by the individual?
Variation within population?
Effect of environment
Effect of natural selection
Human examples
Non-human examples
2. To what extent are human behaviours innate or the product of learning?
a. Watch the video clip on Facial Expressions from the California Academy of Sciences:
(http://www.youtube.com/watch?v=5G6ZR5lJgTI)
b.
c.
d.
e.
What was the research question of the investigation?
What is the effect of the observer on lab-based studies of behaviour?
Why did the blind Olympians provide a good model for research?
What conclusions could be drawn in the study? Why?
3. Outline taxis and kinesis as examples of innate behaviours:
Taxis
Definition:
Positive:
Negative:
Kinesis
Definition:
Positive:
Negative:
Phototaxis
Chemotaxis
Thermotaxis
Orthokinesis
Klinokinesis
e.g.
e.g.
e.g.
e.g.
e.g.
4. Outline an investigation into orthokinesis and klinokinesis of Porcello scaber (woodlouse).
a. Independent variable:
b. Dependent variable
I.
Orthokinesis:
II.
Klinokinesis:
c. Controlled variables:
d. Method for collecting sufficient relevant data:
5. The images below show the results of an investigation into orthokinesis and klinokinesis in P. scaber.
a. Calculate klinokinetic and orthokinetic values for each environment.
b. Compare data collected from the cold and warm environments.
c. Conclude on your results in terms of survival and reproduction.
6. Explain how innate behaviours are the product of natural selection.
7. Define learning.
8. Discuss how the process of learning can improve chances of survival, with reference to non-human examples.
9. Distinguish between these methods of associative learning:
Classical conditioning
Operant conditioning
Imprinting
10. Outline Pavlov’s experiments into classical conditioning, with reference to the terms unconditioned stimulus,
conditioned stimulus, unconditioned response and conditioned response.
11. Birdsong is in part innate and in part learned behaviour. Outline the function of birdsong with regard to sexual
selection.
12. Distinguish between the innate and learned components of birdsong development.
13. Explain how imprinting is vital in the learned part of birdsong development.
14. Birds raised in captivity are not exposed to adult songs or regional dialects of their own songs. Explain why they
will not be reproductively successful if released into the wild.
15. Suggest methods by which captive-reared birds might acquire fully-formed, regional adult birdsongs with help
from their human keepers.
The following questions are taken from an IB Test.
Banded wrens (Thryothorus pleurostictus) are known to sing actively in defence of their territories during the breeding season.
Males possess over twenty different song-types. When two males approach each other near a boundary they engage in
counter-singing and some song-types will be shared. The following diagram shows the pattern of song-types used during an
interaction between two males at their territorial boundary in the Guanacaste Conservation Area, Costa Rica. The arrows
indicate when both males sang identical song-types in succession. The interaction ended without a fight when the males
retreated from the boundary.
G
F
E
bird I
bird J
D
Song-type
C
B
A
Birds approach
Time / 1 song every 11 seconds
Birds retreat
Identify which song-types are shared between both males.
.........................................................................................................................................
(2)
Describe the changes in the song-type pattern during the entire interaction.
..................................................................................................................................................................................................
..................................................................................................................................................................................................
...................... ...........................................................................................................................................................................
(2)
Deduce how a male banded wren can communicate aggressive behaviour.
..................................................................................................................................................................................................
..................................................................................................................................................................................................
....................... ..........................................................................................................................................................................
(2)
(Total 6 marks)
Two groups of 15 rats were trained to escape from an electric shock that was applied to one compartment of their
cages. For one group (labelled EscD) the shock coincided with switching off the light, resulting in darkness in that
compartment. The training was repeated for five sessions. The graphs below show the mean results for the two groups.
Group Esc
Group EscD
3.0
3.0
2.5
2.5
2.0
2.0
Escape 1.5
times / s
1.0
1.5
0.5
0.5
1.0
0.0
0.0
1
2
3
Session
4
5
1
2
3
Session
4
5
[Source: K. Zielinski and Savonenko, (2000), Acta Neurobiol. Exp, 60, pages 457-465]
Calculate the difference in escape times in session 1 between the two groups.
..................................................................................................................................................................................................
............................................................ .....................................................................................................................................
(1)
Suggest a reason for the difference.
..................................................................................................................................................................................................
............................................................ .....................................................................................................................................
(1)
Compare the changes in escape times over the five sessions between the two groups.
..................................................................................................................................................................................................
..................................................................................................................................................................................................
..................................................................................................................................................................................................
(2)
Deduce, giving a reason, which group shows more evidence of learned behaviour.
..................................................................................................................................................................................................
..................................................................................................................................................................................................
(1)
If the researchers were to continue their experiments with the group Esc and apply the same experimental conditions as
for the group EscD, predict what would happen to the escape times for the group Esc.
..................................................................................................................................................................................................
..................................................................................................................................................................................................
(1)
(Total 6 marks)
Name: _________________________________________________ Class/Period:_______________________________
IB Biology SL - Study Guide
Topic 6.5: Nerves PART 2
1. Define synapse.
2. When an AP reaches the terminal end of a neuron, it is converted from an electrical signal to a chemical
message for synaptic transmission. What form does this ‘chemical message’ take?
3. Complete the summary of synaptic transmission below:
4. Neurotrasmitters are specific to their receptors. What does this mean?
5. Some drugs act as competitive inhibitors to neurotransmitters. What would be the effect of this?
Name: _________________________________________________ Class/Period:_______________________________
IB Biology SL - Study Guide
Topic E.4: Neurotransmitters and synapses
1. Distinguish between excitatory and inhibitory pre-synaptic neurons:
Excitatory
Effect on post-synaptic
transmissions
Inhibitory
Stimulates an AP in the
post-synaptic neuron
Method of action
(including ion)
NT binds to receptors.
Potassium gates open.
K+ flows out.
Post-synaptic neuron
hyperpolarizes.
AP is not generated.
Graph of membrane
potential
Example
neurotransmitters
2. Draw a diagram of the dendritic end of a neuron, labeling the axon hillock and showing the direction of nerve
impulses coming into the neuron. What is the function of the axon hillock?
3. Explain how decision-making takes place in the CNS, including the interactions between excitatory and inhibitory
presynaptic neurons and the importance of threshold.
4. Distinguish between spatial and temporal summation.
5. Define psychoactive drug.
6. Explain how psychoactive drugs affect post-synaptic transmissions through either mimicking or blocking normal
neurotransmitters.
7. Explain how this effect on NTs and post-synaptic transmission results in behavioural changes, with reference to
normal behaviour.
8. Categorise the following drugs as either excitatory or inhibitory:
Alcohol, THC (marijuana), nicotine, amphetamines, benzodiazepines, cocaine.
Excitatory:
Inhibitory:
9. Visit the following websites to find out more about how THC and cocaine affect brain activity, including the
methods of action and effects on mood and behaviour.
The Brain from Top to Bottom: http://thebrain.mcgill.ca/flash/index_i.html
Harvard MCB outreach: http://outreach.mcb.harvard.edu/animations/synapse.swf
Jellinek – Drugs and the Brain: http://www.jellinek.nl/brain/index.html
THC
Cocaine
10. Also visit the website Learn.Genetics and find out more about addiction:
http://learn.genetics.utah.edu/content/addiction/
Discuss the causes of addiction:
Genetics - Remember: Susceptibility does not mean inevitability
Psychosocial factors
Dopamine and reward pathways
Name: _________________________________________________ Class/Period:_______________________________
IB Biology SL - Study Guide
Topic 6.5: Nerves PART 3
1. 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
2. The endocrine system is responsible for hormone-mediated communication within the body. Which endocrine
glands are mostly responsible for:
Control of blood sugar
Control of body temperature
Initiation of puberty
Production of sex cells
3. Draw a simple flow chart to show how the endocrine system functions based on stimulus, hormone secretion
and negative feedback control.
4. Define homeostasis.
5. List five factors that are maintained through homeostasis.
6. Complete the flow chart below to show how the hypothalamus controls
body temperature through hormones. What are the body’s responses?
7. Blood glucose levels are maintained by hormones produced in the pancreas. Complete the table to show
glucoregulation.
The pancreas contains…
High Blood Sugar
Low Blood Sugar
___________________ cells…
___________________ cells…
…which secrete…
… carried in blood to….
&
… causing conversion of..
… to …
Overall effect:
Glucose removed from blood
Glucose released into blood
8. Diabetes mellitus is a disease in which regulation of blood glucose is difficult. There are two types of diabetes;
Type I and Type II. Distinguish between them in terms of action, age of onset and risk factors.
Type I:
Type II:
9. Suggest reasons why incidence of diabetes is increasing globally.
Name: _________________________________________________ Class/Period:_______________________________
IB Biology SL - Study Guide
Topic 6.6: Reproduction
1. Draw and label the female reproductive system, including:
Vagina, cervix, uterus, endometrium, fallopian tubes, ovaries. Include also the bladder and urethra.
Annotate the diagram with the function of each part.
2. A typical menstrual cycle lasts around 28 days and is controlled by hormones. Name the origin and state the
main functions of these hormones:
a. Follicle stimulating hormone (FSH)
b. Leuteinising hormone (LH)
c. Oestrogen
d. Progesterone
3. The chart to the right shows hormonal changes
during the menstrual cycle. Describe the events
occurring at:
a. 1-4 days
b. 5-14 days
c. 14-28 days
4. During which days of the cycle is a woman:
a. Most likely to conceive?
b. Least likely to conceive?
5. Distinguish between fertilisation and pregnancy.
6. If a fertilised egg implants onto the endometrium, a hormone called HCG is released. This causes progesterone
levels to remain high, inhibiting FSH and LH. What are two benefits of maintaining high progesterone levels
during pregnancy?
7. Draw and label the male reproductive system, including:
Testis, epididymis, sperm duct, seminal vesicle, prostate gland, urethra, penis and bladder.
Annotate the diagram with the function of each part.
8. What are three functions of testosterone in males?
9. IVF (in-vitro fertilisation) is a reproductive technology that allows those with reproductive problems to conceive
and have a normal pregnancy. Annotate the diagram below with steps of IVF.
10. Discuss the ethical implications of IVF. Consider human rights, morality and religion, safety, cost, psychological
effects, effects on others, economic cost, research and other points of view you feel are appropriate.
Arguments for IVF:
Arguments against IVF: