1. Term 2
INTRODUCTION
This article will tell you how the digestive system functions and what is it. You will see many
images about the digestive system of animals, there will be many videos and also some games in
which you will recognize the parts that composed the digestive system, also cells, and many ways
to see xylem.
Interactive game
http://kidshealth.org/parent/interactive/digestive_it.html
What is the digestive system?
Is when the organs processes food and convert it in little molecules and separate the
minerals, proteins, etc and eliminate the minerals that are not necessary.
“Digestive Systems in Different Animals
“Different species of animals have different digestive systems which are adapted to their
unique requirements. The type of food, method of food gathering and energy needs are
some factors that influence the type of digestive system an animal needs in order to
survive.
Herbivores have a more specialized digestive system than that of a carnivore because it is
more difficult to digest vegetation than meat. The teeth are flat so that grass and plant
material can be ground down, rather than the sharp teeth of carnivores designed to tear
flesh.
Animals which eat both plants and meat, such as humans, have both types of teeth so that
they can perform both functions. In simple animals the digestive system is not complex;
animals require a storage organ, such as the stomach, which allows them usually
containing a single tube. As the animal becomes more complex organs with specialized
functions develop. Higher order to take in large amounts of food in one feeding and then
use its energy over a long period of times. This makes it possible for them to devote time
to activities other than feeding.

2. Bird
Birds need a high body temperature which requires a large
amount of energy to maintain. This means that birds need
to eat larger amounts of food to gain the energy they need
every day to survive.
In order to do this they have a specialized digestive system
where there is an efficient absorption of energy. Food
passes through very quickly and is all absorbed, leaving
little waste. Birds have no teeth so digestion does not
begin in the mouth, all of the food breakdown must occur
within the digestive system. Food enters through the
mouth where it passes down the esophagus into the crop.
This organ is where the food is stored and begins to soften.
From here it moves into the stomach, which is called the
proventriculus. This acts as a true stomach where digestive
juices continue to chemically break down food. The
partially digested food moves into the muscular gizzard,
which has a rough lining to break down the food further. It
sometimes contains sand or pebbles which have been
swallowed by the bird, which add to the grinding process.
The food moves into the intestine, first into the small
intestine and then onto the large intestine. At the point

3. where the small and large intestine meet are two pouches
or caeca, which absorb the water from the food. In
herbivores this is the site of cellulose deposition. The food
becomes harder and enters into a chamber called the
cloaca. It then passes out of the body through the cloacal
lining.
Horse
An adult horse, over five years old, has 40-42 teeth which include incisors, canines and cheek
teeth. The incisors work together with the lips to grasp and move food around the mouth. The
molars are used to grind down food, making it easier to digest. The digestive system has
developed to effectively break down and digest fodder, with the stomach being smaller than that
of other cud chewing animals.
The average adult horse is able to hold 7.5-9.5 litres (2-2.5 gallons) of chyme in their stomach. The
small intestine is 18-21 meters (60-70 feet) long, while the large intestine is enormous, adapted to
digesting grass and hey. The caecum is a pocket between the large and small intestine and is able
to hold 15-65 liters (4-17 gallons) while the large colon can hold 60-150 liters (16-34 gallons). In
the large intestine food is broken down through fermentation by both bacteria and protozoa. Food
may remain in the intestine for up to 55 hours.
Insect
The digestive system in insects is basically a tube that begins at the mouth and ends at the rectum.
It can be divided into a pharynx, esophagus, stomach, intestine, colon and rectum. The stomach or
midgut has glands called the gastric ceca which secrete the digestive juices. The malpighian tubes
remove the nitrogen rich waste from the blood. Each tube empties at the connection between the
stomach and large intestine, producing an end product of uric acid, which is passed with faces.
Insects such as the praying mantis are carnivorous and begin to digest their food by chewing.
Other insects such as wasps paralyse their pray and lay their eggs in the bodies. This provides a
living food supply for the young, providing their immediate source of food. Termites gain their
energy from wood and begin to digest the cellulose before it enters the digestive system.
Protozoans are released onto the wood and begin its breakdown, continuing to act on the wood
once it is passed onto the stomach. Flatworms have a simple digestive system, with a single tube
serving as both mouth and anus.
Snake
Snakes eat all parts of their pray and need a specialized digestive system to gain the most
nutrients from their food. Their teeth are very thin and usually curve backwards. Their function is
not to grind down food as it is in most animals; rather it is to capture prey. The food is swallowed
whole, thus the teeth perform a specialized function. They have powerful digestive enzymes to
break down the hair, feathers, bones, organs and other parts of their food.
The salivary glands also produce strong enzymes which are also used to kill the organism. If saliva
enters the wounds of the animal it will begin the digestive process and cause severe tissue

4. damage, which can often lead to the death of the animal. These toxic substances are found in the
saliva of many non poisonous snakes. In poisonous snakes it is the salivary glands which have
developed into venom sacks, with the venom being a highly toxic form of saliva.
Mollusk
The mollusk digestive system has millions of microscopic hair like fibers along the main digestive
tract and has several divisions for the different organs.
The first section contains the mouth and esophagus and is the site of the initial breakdown of
food. There is a specialized file like radual found in the mouth, which acts like teeth or a tongue in
the food breakdown.
Oysters, clams and muscles do not feature the radula, as they are filter feeders, the food is already
filtered when it enters the mouth and continues down the digestive tract. It reaches the liver and
stomach, which continues the digestion. In many mollusks the stomach has a flexible rod, which is
made up of mucus and proteins in a crystalline structure. This secretes the digestive juices and
enzymes and acts as a kind of stirring stick, mixing up the stomach contents to aid digestion. The
final section of the digestive tract contains the intestine and anus, from which the waste is
removed.”
What are the organs that process the digestive system?
The mouth: the mouth is used to convert food in little pieces of it
Esophagus: is used to transport the little pieces of food to the stomach
Stomach: mix the food with gastric juices and melts the food.
Duodenum: is when the food is separate into needed thing and other things that are don’t needed
and is transport it to the anus
Small intestine: the nutrients are taken to the blood.
Large intestine: absorb the water and the solids are taken to the anus
Anus: is when the solids are eliminated

5. On the digestive system the organs function in order that the nutrients that are not needed are
expulsed by the anus and the nutrients, mineral, vitamins that are needed, are taken in which
they belong to.
The digestive system starts with the mouth that mashes the food, after is transported by the
esophagus to the stomach on the stomach the food is mixed with HCI (hydrochloric acid) after is
transported to the duodenum in there the nutrients are separated with the solids that are not
needed then that solids are transported to the small intestine after is taken to the large intestine

6. in there the water of the solids are absorbed, later is taken to the anus in there that solids are
expulsed.
Ways of see the xylem, phloem and stomata and understanding what is
Xylem: is the principal water-conducting tissue vascular plants also Xylem caries water and
dissolved nutrients from the roots throughout the plant.
Phloem: is movement of water through the xylem it also carries distributes the products of
photosynthesis (mainly from the leaves) to the rest of the plants.
Stomata: Are apertures structure on a plant
How to see Xylem, phloem and stomata
1. You have to look for a plant with cute stem
2. Look at the plant and see the stem it have or the leave
3. With a knife or something, cut a little bit of the stem or with the leave take out the vein
and cut it
4. In a slide with another slide on top put it on the microscope and in there you will see all
xylem, phloem and stomata

7. 1. The carbon cycle begins with photosynthesis in plants
False
Plants are primary consumers of carbon dioxide.
True
Animals are primary consumers of carbon dioxide.
False
Humans are producers of carbon dioxide.
True
Carbon dioxide is easily dissolved in water.
True
Humans and animals release carbon dioxide into the air during photosynthesis

8. False
All of the carbon in existence is continually recycled in the carbon cycle
True
Where does the carbon come from that the plants use?
Air
Are human’s primary consumers of carbon dioxide or secondary consumers?
Neither. Humans produce carbon dioxide
How does carbon get into the soil?
All of the above
2. Where does photosynthesis take place?
in the chloroplast
What is the first step in photosynthesis?
Trapping sunlight
In addition to sunlight, what else is required for photosynthesis to take place?
Carbon dioxide and water
How many groups of reactions take occur in the process of photosynthesis?
Two
What are the products of photosynthesis?
Sugar and oxygen
What are the products of photosynthesis?
Respiration
What happens to sunlight in photosynthesis?
It's converted to chemical energy and stored
Which group of reactions is responsible for the photo in photosynthesis?
Light reactions

9. Which group of reactions is responsible for the synthesis in photosynthesis?
Dark reactions
3. Which cell feature is responsible for making proteins?
Ribosomes
What is the name of the jelly-like substance that is inside the cell?
Cytoplasm
What cell feature is responsible for powering the cell?
Mitochondria
Where in the cell does DNA replication take place?
Nucleus
What is one major feature that plant cells have that animal cells do not?
Cell wall
What is one major feature that plant cells have that animal cells do not?
Lysosomes
Which cell feature processes proteins?
golgi apparatus
Which cell feature transports ribosomes?
endoplasmic reticulum
The plant cell structure where photosynthesis takes place is called...
Chloroplast
What cell feature is responsible for storing water?
Vacuole
Cells are the Starting Point

10. All living organisms on Earth
are divided in pieces called
cells. There are smaller
pieces to cells that
include proteins andorganell
es. There are also larger
pieces
called tissues andsystems.
Cells are small compartments
that hold all of the biological equipment necessary to keep an organism
alive and successful on Earth.
A main purpose of a cell is to organize. Cells hold a variety of pieces and
each cell has a different set of functions. It is easier for an organism to grow
and survive when cells are present. If you were only made of one cell,
you would only be able to grow to a certain size. You don't find single
cells that are as large as a cow. Also, if you were only one cell you
couldn't have a nervous system, no muscles for movement, and using the
internet would be out of the question. The trillions of cells in your body
make your life possible.