A SINGLE LESSON PLAN
Student Teacher
Jessica Mason
Class
Mr U class
Date
Lesson Topic
Digestion
Subject
Year 11 Biology
Period
1
No. of Students
Length Of time
50 minutes
Rationale
Outcomes
8.3:
 Explain the relationship between the length and overall complexity of digestive systems of a vertebrate herbivore and a vertebrate carnivore with respect to:
– the chemical composition of their diet
– the functions of the structures involved
 Identify data sources, gather, process, analyse and present information from secondary sources and use available evidence to compare the digestive systems
of mammals, including a grazing herbivore, carnivore and a predominantly nectar feeding animal
Preparation and Planning (Equipment needed, stencils/OHP, videos booked, books collected etc)
A herbivore (ringtail possum) a carnivore (tawny frogmouth) to compare as a visual reference and talking point Provided by Australian Wildlife Displays through Miss Mason
Prezi presentation from: http://prezi.com/l4ituregbkxu/digestion/
Youtube clip http://www.youtube.com/watch?v=P5lyQUtq1KQ&feature=related
Data projector
Laptop
Assessment Tasks (Where relevant)
Compare the digestive systems of mammals, including a grazing herbivore, carnivore and a predominantly nectar feeding animal. Students need to find the data, using the textbook and
internet and reference these resources. Present comparison in a one A4 page handout as if they had to present to non-biologists at the school i.e. explain some of the more difficult terms.
They may use tables and diagrams.
Follow –up Activity (Homework Instructions, collecting work, guidelines for next lesson)
For homework read pages 74 to 78 about digestion, Questions 2.86 numbers 1 and 5.
A SINGLE LESSON PLAN
Lesson Sequence (Strategies, procedures, tasks, etc)
Student Activity
Teacher Activity
Est Time
Roll Call
Fulfilling roll call
3
Introduction Slide: last week we spoke about teeth and their role in breaking
down our food so the digestive juices can react faster with the particles to aid faster
digestion. Today we will look specifically at the digestive system. Another name for
the digestive tract is an Alimentary Canal, we’ll read about it a bit later, but
essentially, our digestive system is outside of our body, and nutrients pass through
its walls INTO our body from it. First we will watch this video
Watching slides, taking notes on the information presented about the
digestive systems.
3
Slide: Teacher puts on Youtube clip ‘The Digestive System’.
http://www.youtube.com/watch?v=P5lyQUtq1KQ&feature=related
Watching video
4
That was the human digestive system. We are of course, omnivores, so are in
between the extremes for digestive systems… and by extremes I mean where
structures in the system have been modified for specialisations in food types. Ok first
we will be looking at
Who can name a herbivorous mammal? (Possums, bandicoots, rabbits, cow
though they aren’t native)
Slide: Cow
Slide: Ringtail Possum
If we look at a local native mammal, more specifically a marsupial, we have a ringtail
possum. They have a bit of a varied diet compared to that of the koala in your
textbook, but they do share a lot of the same foods, which would most likely be?
(gum leaves).
Leaves have a high cellulose level, and that needs to be broken down in order to get
the molecules of nutrients that are inside the cells to be useable to the body.
Possums will also break down the cellulose into glucose through digestion to gain
some of the energy. They do this by having an enlarged Ceacum where the
cellulose is broken down by bacteria and the glucose can then be absorbed. The
small intestine is covered by protrusions to increase the surface area for absorption,
the protrusions are called Villae and microvillae and they absorb the nutrient
molecules into the blood stream. Once the cellulose has been processed in the
Ceacum, the left overs from the meal which consists of mostly fibre, are passed into
the long intestine which extracts any extra water and then the remainder is excreted
through the anus.
There are 2 types of excrement, Caecal pellets and Faecal pellets – they eat the
Caecal pellets which contain undigested nutrients, and also feed them to their babies
to enable them to have the right gut flora to digest food in their own Caecum.
(Example of a Ringtail Possum aka Blossom with example of her food)
Gum leaves are toxic, the way the possums and koalas (as found in the textbook
example) get around this is with the enzymes and microbiota in their stomachs
Watching slides, taking notes on herbivorous digestive systems
Looking at, patting if they wish Blossom the ringtail possum, asking any
questions
A SINGLE LESSON PLAN
breaking them down and the liver does the rest. We cant eat them, it’d make us
really sick.
Who can name a carnivorous animal that lives locally? (owls, tawny
frogmouths, kookaburras, occasionally blue tongue lizards)
Slide: Tawny Frogmouth, Tasmanian Devil, Eagle… (2012; 2012; 2012;
Johnson 2012)
Carnivorous animals have a tiny Caecum, they do not eat much, if any, vegetation so
have no need for the added fermentation and digestion that occurs in the Ceacum.
They have a much shorter digestive system as the nutrients are broken down
through the stomach, small intestine and anything that is not absorbed is then
excreted after the large intestine. Nutrients are more concentrated in meat than in
vegetation, so there is no need for such an extended digestive tract as it is in
herbivores which need more time to extract the nutrients from the food.
An example of a carnivorous local animal is this Tawny Frogmouth. It is not
an owl, though many people confuse it with owls. They are more closely related to
Kookaburras and mainly eat moths in the wild and other insects. Today though, he
will be eating some chicken. Not only does his digestive system break down the
meat matter, it also breaks down the calcium and other hard substances,
unfortunately though, a lot of that comes out the other end, as there is no use for it
in the body. Because his digestive system is shorter than Blossom’s, a few hours
after feeding he will generally do a big and smelly poo. In birds, what they excrete is
a mixture of what we would term urine and faeces. We will talk about other body
systems in the coming weeks, but just so you know, birds. marsupials and reptiles
have cloacas, a single opening for urine, excrement and reproductive organs.
Watching slide, taking notes on carnivorous digestive systems
Watching, patting, asking questions re: Tawny Frogmouth
Slide comparing the two digestive systems, which is the carnivore, and
which is the herbivore?
Slide comparing the two systems, answering the question
We’ve talked about herbivores and carnivores, can anyone think of any
other kind of food that an animal may have a specialised digestive tract
for? Exlcuding Omnivores as we covered that with humans.
(Nectivores)
Slide: Flying Fox
There are many species that specialise in eating nectar. I wasn’t able to bring my
favourite one in today, but here is a picture of a few of the characters I could have
brought in. The main reason is that they smell pretty bad. These are Flying Foxes.
Generally they feed on nectar and fruit. In captivity it is hard to get enough nectar
just for one bat for one night, so they are fed on fruit. Fruit has everything that
nectar has except for protein, so protein supplement is added to all fruit meals for
the bats.
Answering question
Slide: honey possum (2012)
Slide of nectar feeders.
A SINGLE LESSON PLAN
Slide: Honey possum digestive system
A nectar feeder has a very under-developed digestive tract compared to herbivores
and carnivores. It has no Ceacum, and there are 2 stomachs which are basically
holding cells for the nectar. Nectar doesn’t take a lot to digest, so most of the
digestion occurs in the small intestine which does not differ greatly from the large
intestine to the untrained eye, so they are hard to differentiate, unlike carnivores and
herbivores.
Slide honey possum digestive system
Slide: Rattlesnake (2012)
In a snake, (Which are all carnivorous, some even cannibalistic) the digestive system
contains the same as the other carnivores, it is just elongated. Bring out python.
Slide snake, look at and touch snake if they wish to.
Slide: Frog
We looked at frog respiration last week, so here is a good first hand look at a frog
(bring out frog), and in your text book reading that you are doing after this and for
homework you will see a short segment on Frog digestion… interestingly, as they
metamorphose from tadpole to frog, their digestive tract becomes shorter as they
move from herbivory to carnivory.
Look at frog.
Slide: Homework/Assignment
For homework please read pages 74 to 78 about digestion, if you don’t
need the recap on teeth you can skip that section and do Questions 2.86
numbers 1 and 5. You will also be doing question 4 as a written submitted
assignment on digestion. (Abusson, Kennedy et al. 2004)
Compare the digestive systems of mammals, including a grazing herbivore,
carnivore and a predominantly nectar feeding animal. You need to find the
data, using the textbook, internet and reference these resources. Present
your comparison in a one A4 page handout as if you had to present to nonbiologists at the school i.e. explain some of the more difficult terms. You
may use tables and diagrams.
Basically need to address the differences in chemical composition of their
foods, and how the function of the structures of the digestive systems
work and differ from one another.
Write down homework and assignment, get started if there is time left.
A SINGLE LESSON PLAN
References/Resources
(2012). "Anatomy of a Snake." Retrieved 31/5/2012, 2012, from http://visual.merriam-webster.com/images/animal-kingdom/reptiles/snake/anatomy-venomoussnake.jpg.
(2012). "Eastern Quoll." Retrieved 31/5/2012, 2012, from http://www.dpiw.tas.gov.au/inter.nsf/Images/BHAN-5347K3/$File/wildlife_equoll1.jpg.
(2012). "Interesting Topics." Retrieved 31/5/2012, 2012, from http://www.interestingtopics.net/storage/picture27.jpg.
(2012). "Lee's birdwatching adventures." Retrieved 31/5/2012, 2012, from http://leesbirdblog.files.wordpress.com/2009/08/tawny-frogmouth-podargusstrigoides-by-marc-at-africaddict.jpg.
(2012). "Veterinarians and Animal World." Retrieved 31/5/2012, 2012, from http://vincentiusabbath.blogspot.com.au/2012/01/tarsipedidae.html.
Abusson, P., E. Kennedy, et al. (2004). Biology in Context: The Spectrum of Life. New York, Oxford Press.
Johnson, S. (2012). "Tasmanian Devil." Retrieved 31/5/2012, 2012, from http://www.parks.tas.gov.au/index.aspx?base=387.
http://www.cteonline.org/portal/default/Curriculum/Viewer/Curriculum?action=2&view=viewer&cmobjid=178310