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Unit 3 G9 Animal and Plant Nutrition

Teacher(s) Sam Rajesh
Unit title
Subject group
Plants and Animals Nutrition
MYP year
and Biology
Inquiry: Establishing the purpose of the unit
Key concept
Related concept(s)
Global context
Identities and Relationships
Statement of inquiry
Systems in living organisms transfer energy and nutrients from the environment to cells, where they are used to maintain
life balance. Diet can be affected by personal and cultural choices.
Inquiry questions
Factual— What nutrients do organisms need to survive? What occurs during the process of gas exchange?
Conceptual— What processes are involves in movement and transport? Why do conditions within organisms need to be
kept in balance.
Debatable— Should people use drugs to try to control their weight?
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Criterion A: Knowing and
understanding Students develop
scientific knowledge (facts, ideas,
concepts, processes, laws, principles,
models and theories) and apply it to
solve problems and express
scientifically supported judgments.
Criterion B: Inquiring and designing
Students develop intellectual and
practical skills through designing,
and performing scientific
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Summative assessment
Outline of summative assessment task(s) Relationship between summative
including assessment criteria:
assessment task(s) and statement of
Summative assessment on Digestive
During the written assessment, students
will be tested upon their knowledge and
understanding of concepts relating to
Digestive system.
Students will be tested for their ability
to design simple experiment to
demonstrate the presence of macro
molecules present in different food
Approaches to learning (ATL)
Thinking - Critical Thinking.
Diets in most countries depend on a staple food such as bread, potatoes or rice, which is usually the main source of
carbohydrate. Learners should be aware of the main sources of each type of nutrient in their own country, but also be
prepared to consider how diets differ in other parts of the world.
Extension activity: the Association for Science Education has a project called Science Across the World, which includes a
unit on diet, and encourages schools in different parts of the world to share information.
Learners can keep a record of the food that they eat during a short period of time and then consider whether they are
obtaining the nutrients that they need. Their diet could be analysed using standard food tables or by accessing the nutrient
data laboratory. Alternatively learners could use the interactive balanced diet activity.
Action: Teaching and learning through inquiry
Learning process
After studying Chapter B3
you should know and
understand the following.
Learning experiences and teaching strategies
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 Dietary needs are
affected by the age,
gender and activity of
 Growing children
and pregnant women
have special dietary
 Malnutrition is the
result of taking in
food which does not
match the energy
needs of the body, or
is lacking in proteins,
vitamins or minerals.
 The effects of
malnutrition include
starvation, coronary
heart disease,
constipation and
 Western diets often
contain too much
sugar and fat and too
little fibre.
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Week 1:
Students will understand ingestion as the taking of substances, e.g. food and drink, into the body
through the mouth. Define chemical digestion as the breakdown of large, insoluble (food)
molecules into small, (water-) soluble molecules. Define absorption as the movement of small
food molecules and ions through the wall of the intestine into the blood.
Week 2 and 3:
Define absorption as the movement of small food molecules and ions through the wall of the
intestine into the blood.
Define assimilation as the movement of digested food molecules into the cells of the body where
they are used, becoming part of the cells. Define egestion as the passing out of food that has not
been digested or absorbed, as faeces, through the anus
Identify the main regions of the alimentary canal and associated organs, limited to mouth,
salivary glands, oesophagus, stomach, small intestine, pancreas, liver, gall bladder, large intestine
and anus.
Week 4 and 5
Describe the functions of the regions of the alimentary canal listed above, in relation to ingestion,
digestion, absorption and egestion of food.
State the significance of chemical digestion in the alimentary canal in producing small, soluble molecules
that can be absorbed
State the significance of chemical digestion in the alimentary canal in producing small, soluble molecules
that can be absorbed
Explain the functions of the hydrochloric acid in gastric juice, limited to the low pH:
– denaturing enzymes in harmful
Obesity results from
taking in more food
than the body needs
for energy, growth or
 Malnutrition
includes kwashiorkor
and marasmus.
Week 6 Explain the significance of villi in increasing the internal surface area of the small intestine.
Week 7:
Plants can be considered as food factories, in which all the food in the world is initially made.
Learners should compare the needs of animals for organic nutrients, in Unit 2, with those of plants, which only require
inorganic compounds such as carbon dioxide and water for photosynthesis. Consumers compared with producers, this is a
cross-link to Unit 9.
The process of photosynthesis should be considered at a fairly basic level, the light-dependent and light-independent
 The blood in the
stages should not be introduced.
capillaries picks up
The important point to get across is the conversion of light energy to chemical energy. Chlorophyll absorbs light energy and
oxygen from the air
enables it to be used to drive the reactions. (Ensure that learners do not think that chlorophyll attracts light.)
in the alveoli and
gives out carbon
The initial products of photosynthesis are sugars (such as glucose) which can be converted to large, insoluble molecules
dioxide. This is called such as starch for storage within the plant.
gaseous exchange.
Week 8
 The oxygen is carried
round the body by the . Learners should know how to test a leaf for starch and to carry out simple experiments into the need for light and
blood and used by the chlorophyll for photosynthesis.
cells for their
The importance of controlled variables such as temperature can be introduced.
The concentration of carbon dioxide can be changed using sodium hydrogen carbonate solution of different concentrations.
 During exercise, the
rate and depth of
The exchange of gases can be more easily understood when the structure of the leaf has been studied (in Unit 3).
breathing increase.
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This supplies extra
oxygen to the
muscles and removes
their excess carbon
During physical
activity increases in
levels of carbon
dioxide in the blood
are detected in the
brain, causing an
increased rate of
Goblet cells make
mucus to trap
pathogen and
particles to protect
the gas exchange
Ciliated cells move
mucus away from the
Tobacco smoke can
cause COPD, lung
cancer and coronary
heart disease.
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Investigations with Elodea (Canadian pondweed) can produce good quantitative data to illustrate the effect of light on the
rate of photosynthesis.
Temperature could also be considered but this is not so easy to carry out in the school lab.
Formative assessmentTask 1:
Students in groups completed worksheets on the characteristics of living things.
Learner activity- characteristics of living things(including video clips and worksheets)
Task 2:
 Tobacco smoke
affects the gaseous
exchange system
ecause it contains
toxic components,
including carbon
monoxide, nicotine
and tar.
Students explored cellsalive.com to view different types of cells and identified the
important cell components.
 Alveoli in the lungs
are very numerous,
provide a large
surface area, have a
thin, moist surface
and are wellventilated for
efficient gas
exchange. Alveoli
have a good blood
supply. Exchange of
oxygen and carbon
dioxide in the alveoli
takes place by
 Define photosynthesi
Osmosis animation and text:
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Use of microscope, bioviewers or cellsalive.com website to look at palisade cells and liver cells.
Use of microscopes to view specimens.
Task 3:
Students in groups watched a slideshow showing the direction of movement of water between
two different concentrations of sugar solutions.
Studnent are grouped based
 State the word
equation for
carbon dioxide +
water → glucose +
oxygen, in the
presence of light and
 Investigate the
necessity for
chlorophyll, light and
carbon dioxide for
photosynthesis, using
appropriate controls
 Describe the
importance of: nitrate
ions for making
amino acids;
magnesium ions for
making chlorophyll
 Explain the effects of
nitrate ion and
magnesium ion
deficiency on plant
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 Describe the
significance of the
features of a leaf in
terms of functions, to
include: palisade
mesophyll and
distribution of
chloroplasts –
stomata, spongy
mesophyll cells and
guard cells – gas
exchange; xylem for
transport and support;
phloem for transport.
 Identify the main
regions of the
alimentary canal and
associated organs,
including mouth,
salivary glands,
esophagus, stomach,
small intestine,
pancreas, liver, gall
bladder, large
intestine, and anus
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 Explain the effects of
physical activity on
rate and depth of
breathing in terms of
the increased carbon
dioxide concentration
in the blood, causing
an increased rate of
 Explain the role of
goblet cells, mucus
and ciliated cells in
protecting the gas
exchange system
from pathogens and
 State that tobacco
smoking can cause
chronic obstructive
pulmonary disease
(COPD), lung cancer
and coronary heart
 Describe the effects
on the gas exchange
system of tobacco
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smoke and its major
toxic components,
limited to carbon
monoxide, nicotine
and tar
 Define aerobic
respiration as the
chemical reactions in
cells that use oxygen
to break down
nutrient molecules to
release energy
Reflection: Considering the planning, process and impact of the inquiry
Prior to teaching the unit
During teaching
With regards to this topic being
enjoyable, it is intended that starting
with the different types of cells and
functions aspect will be an excellent
way to ease into IGCSE Biology.
Students enjoyed the Osmosis
experiment and collect quatitative data
to prove that the cell’s outer surface of
the plasma membrane is in contact with
this external environment, while the
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After teaching the unit
Examples of Osmosis and Diffusion
will be an exciting topic; for instance,
osmosis includes red blood cells
swelling up when exposed to fresh
water and plant root hairs taking up
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inner surface is in contact with the
cytoplasm. Thus, the plasma membrane
controls what enters and leaves the cell.
There were questios about the
similarities and differences between
osmosis and diffusion or how to
compare and contrast the two forms of