The document discusses the organization of multi-cellular organisms from cells to tissues to organs to systems and organisms. Cells form tissues, tissues form organs, organs work together in systems, and systems make up the whole organism. Having many cells allows multi-cellular organisms to have specialized cells, tissues and organs that can each perform different functions, unlike single-celled organisms that rely on one cell to carry out all functions. If one cell dies in a multi-cellular organism, other cells can perform its function, but single-celled organisms would die if their only cell died.

2. Cells and
Systems PBL

3. Cells and
Systems PBL
Harshil Bhesania, Umar
Usmani, Thean

5. Parts of the Digestive System

6. Parts of the Digestive System
• Mouth - the first part of the digestive system, where food enters the body. Chewing and salivary enzymes
in the mouth help in the breaking down the food.
• Salivary glands - glands located in the mouth that produce saliva. Saliva contains enzymes that break
down carbohydrates into smaller molecules.
• Esophagus - the long tube between the mouth and the stomach. It uses rhythmic muscle movements
(called peristalsis) to force food from the throat into the stomach.
• Stomach – is a muscular organ that is attached to the esophagus. Both chemical and mechanical digestion
takes place in the stomach. When food enters the stomach, it is mixed in acids and enzymes.
• Liver - a large organ located above and in front of the stomach. It filters toxins from the blood, and makes
bile (which breaks down fats) and some blood proteins.
• Gall bladder - a small, sac-like organ located by the duodenum. It stores and releases bile (a digestive
chemical which is produced in the liver) into the small intestine.
• Pancreas - an enzyme-producing gland located below the stomach and above the intestines. Enzymes
from the pancreas help in the digestion of carbohydrates, fats and proteins in the small intestine.
• Small Intestine – bile, pancreatic enzymes, and other digestive enzymes produced by the inner wall of the
small intestine help in the breakdown of food. Most food is absorbed here.
• Large Intestine - The large intestine is responsible for absorption of water and excretion of solid waste
material.
• Rectum - the lower part of the large intestine, where feces are stored before they are excreted.
• Anus - the opening at the end of the digestive system from which feces (waste) exits the body.

8. How does the Digestive System
work?

9. How does the Digestive System
work?
• The process starts from the mouth where the food gets break
down by chewing and with the chemical reaction with the
saliva. The saliva helps break down carbohydrates. The saliva
(spit) has chemical enzymes which break down the
carbohydrates to make it into small molecules. Then the food
goes through the throat by the esophagus which has peristalsis
which is wavy muscles to forces the food down to the stomach.
The stomach has acids to digest the food. The liver makes bile,
extracts and breaks down the fat and some blood proteins; it
also helps the small intestine in digesting food. The
Gallbladder stores the bile and releases the bile to the small
intestine. The pancreas has enzymes which help in digestion of
carbohydrates and sends fat and proteins to the small intestine.
There are 2 types of intestines a small intestine and a big
intestine. The small intestine breaks down food and absorbs
the nutrients. The big intestine reabsorbs water and extracts
solid materials to form waste. Then the feces are stored at the
Rectum. Then the feces exit the body from the Anus.

11. Disorders of Digestive
System

12. Disorders of Digestive
System
• Gastro esophageal reflux disease: This disease is a
condition in which the food and liquid goes backwards
from the stomach and makes its way to the esophagus.
This will irritate the esophagus and cause heartburn and
other problems. People are likely to get this disease if the
consume alcohol, are obese, if they are smoking and if
they suffer from Scleroderma which is a connective tissue
disease.
• To avoid this disease you will have to reduce the amount
of caffeine, chocolate, peppermint, spearmint, and alcohol
that you consume. Try to avoid carbonated drinks like
Pepsi, Coke, Sprite, etc. If you have Gastro esophageal
reflux disease ( GERD ), avoid eating fatty foods.

14. What is the function of the
Respiratory System?

15. What is the function of the
Respiratory System?
• Your respiratory system is made up of the organs in your
body that help you to breathe. The primary function of the
respiratory system is to supply the blood with oxygen in order
for the blood to deliver oxygen to all parts of the body. The
respiratory system does this through breathing. Breathing in
(inhalation) fills our lungs with oxygen-containing air.
Breathing out (exhalation) gets rid of the waste in our body
like carbon dioxide. The organs involved in this gas exchange
form the respiratory system. The respiratory system is
responsible for gas exchange. This exchange of gases is the
respiratory system's means of getting oxygen to the blood.
The goal of breathing is to deliver oxygen to the body and to
take away carbon dioxide. Remember, that Respiration =
Breathing.
• The respiratory system takes air into the lungs. It puts oxygen
into the blood and takes the carbon dioxide out of the blood
and exhales it.

17. How does the Respiratory System

18. How does the Respiratory System
• Respiration is achieved through the mouth, nose, trachea, lungs, and
diaphragm. Oxygen enters the respiratory system through the mouth and the
nose. The oxygen then passes through the larynx (where speech sounds are
produced) and the trachea, which is a tube that enters the chest cavity. In the
chest cavity, the trachea splits into two smaller tubes called the bronchi.
Each bronchus then divides again forming the bronchial tubes. The
bronchial tubes lead directly into the lungs where they divide into many
smaller tubes, which connect to tiny sacs called alveoli. The inhaled oxygen
passes into the alveoli and then diffuses through the capillaries into the
arterial blood.

20. Parts of the Respiratory
System

21. Parts of the Respiratory
System
Organs involved are:
•Larynx – Place where moving air being breathed in and out creates sounds
•Trachea – This is the windpipe, or the passage leading from the mouth and
throat to the lungs
•Lungs – The lungs perform respiration or gas exchange
•Bronchi or Bronchus – The two main tubes of the lungs
•Bronchioles – The smaller divisions of the bronchi
•Alveolus – The very small air sacs where breathed in air goes
•Diaphragm – Strong wall of muscle that separates the chest cavity from the
abdominal cavity

22. Organs involved are:
•Larynx – Place where moving air being breathed in and out creates sounds
•Trachea – This is the windpipe, or the passage leading from the mouth and
throat to the lungs
•Lungs – The lungs perform respiration or gas exchange
•Bronchi or Bronchus – The two main tubes of the lungs
•Bronchioles – The smaller divisions of the bronchi
•Alveolus – The very small air sacs where breathed in air goes
•Diaphragm – Strong wall of muscle that separates the chest cavity from the
abdominal cavity

26. What is the function of the Nervous
System?

27. What is the function of the Nervous
System?
• The brain is a central computer that controls all bodily
functions, and the nervous system is like a network that
relays messages back and forth from the brain to different
parts of the body. It does this via the spinal cord, which runs
from the brain down through the back and contains
threadlike nerves that branch out to every organ and body
part. When a message comes into the brain from anywhere
in the body, the brain tells the body how to react. For
example, if you accidentally touch a hot stove, the nerves in
your skin shoot a message of pain to your brain. The brain
then sends a message back telling the muscles in your hand
to pull away. The Nervous system coordinates and controls
the actions of the organs and organ systems.

29. How the does the Nervous System
Work?

30. How the does the Nervous System
Work?
• The Nervous System works by sending signals to other parts of
the body. For example the brain sends a signal to the circulatory
system that tells the heart to pump blood. The functions of the
nervous system are done by the action of millions of nerve cells.
The cells are called neurons, and they are the basic functioning
cells of the nervous system. The cells (neurons) not only gather
and process information but also generate proper response
signals to the every part of the body. The nervous system works
with every system because it spreads around your whole body.
It is what tells the heart to pump, the lungs to breath. Without it
the body couldn't function. The nervous system is the major
controlling, regulatory, and communicating system in the body.
The function of the nervous system depends on cells called
neurons. These neurons carry impulses from the sensory
receptors to the CNS. Sensory receptors are located in the skin,
eyes, ears, tongue and nose. The nervous system basically
works by neurons, or nerve cells.

31. • The Nervous System works by sending signals to other parts of
the body. For example the brain sends a signal to the circulatory
system that tells the heart to pump blood. The functions of the
nervous system are done by the action of millions of nerve cells.
The cells are called neurons, and they are the basic functioning
cells of the nervous system. The cells (neurons) not only gather
and process information but also generate proper response
signals to the every part of the body. The nervous system works
with every system because it spreads around your whole body.
It is what tells the heart to pump, the lungs to breath. Without it
the body couldn't function. The nervous system is the major
controlling, regulatory, and communicating system in the body.
The function of the nervous system depends on cells called
neurons. These neurons carry impulses from the sensory
receptors to the CNS. Sensory receptors are located in the skin,
eyes, ears, tongue and nose. The nervous system basically
works by neurons, or nerve cells.

35. Parts of the Nervous System

36. Parts of the Nervous System
Parts involved in the Nervous System:

37. Parts of the Nervous System
Parts involved in the Nervous System:

38. Parts of the Nervous System
Parts involved in the Nervous System:
• Brain - It helps to control all of the body systems and organs, keeping them
working like they should. The brain also allows us to think, feel, remember
and imagine.

39. Parts of the Nervous System
Parts involved in the Nervous System:
• Brain - It helps to control all of the body systems and organs, keeping them
working like they should. The brain also allows us to think, feel, remember
and imagine.
• Spinal Cord - The brain communicates with the rest of the body through the
spinal cord and the nerves. Information passed through the spine tells the
body what to do and when to do it.

40. Parts of the Nervous System
Parts involved in the Nervous System:
• Brain - It helps to control all of the body systems and organs, keeping them
working like they should. The brain also allows us to think, feel, remember
and imagine.
• Spinal Cord - The brain communicates with the rest of the body through the
spinal cord and the nerves. Information passed through the spine tells the
body what to do and when to do it.
• Nerve Cells - Neurons carry messages in the form of a electrical impulses.
The messages move from one neuron to another to keep the body
functioning.

41. Parts of the Nervous System
Parts involved in the Nervous System:
• Brain - It helps to control all of the body systems and organs, keeping them
working like they should. The brain also allows us to think, feel, remember
and imagine.
• Spinal Cord - The brain communicates with the rest of the body through the
spinal cord and the nerves. Information passed through the spine tells the
body what to do and when to do it.
• Nerve Cells - Neurons carry messages in the form of a electrical impulses.
The messages move from one neuron to another to keep the body
functioning.
• Neurons- the cells that make up the nervous system are called neurons.
Neurons carry the electrical messages that are the "language" of the nervous
system.

42. Parts of the Nervous System
Parts involved in the Nervous System:
• Brain - It helps to control all of the body systems and organs, keeping them
working like they should. The brain also allows us to think, feel, remember
and imagine.
• Spinal Cord - The brain communicates with the rest of the body through the
spinal cord and the nerves. Information passed through the spine tells the
body what to do and when to do it.
• Nerve Cells - Neurons carry messages in the form of a electrical impulses.
The messages move from one neuron to another to keep the body
functioning.
• Neurons- the cells that make up the nervous system are called neurons.
Neurons carry the electrical messages that are the "language" of the nervous
system.

43. Parts of the Nervous System
Parts involved in the Nervous System:
• Brain - It helps to control all of the body systems and organs, keeping them
working like they should. The brain also allows us to think, feel, remember
and imagine.
• Spinal Cord - The brain communicates with the rest of the body through the
spinal cord and the nerves. Information passed through the spine tells the
body what to do and when to do it.
• Nerve Cells - Neurons carry messages in the form of a electrical impulses.
The messages move from one neuron to another to keep the body
functioning.
• Neurons- the cells that make up the nervous system are called neurons.
Neurons carry the electrical messages that are the "language" of the nervous
system.

44. Parts involved in the Nervous System:
• Brain - It helps to control all of the body systems and organs, keeping them
working like they should. The brain also allows us to think, feel, remember
and imagine.
• Spinal Cord - The brain communicates with the rest of the body through the
spinal cord and the nerves. Information passed through the spine tells the
body what to do and when to do it.
• Nerve Cells - Neurons carry messages in the form of a electrical impulses.
The messages move from one neuron to another to keep the body
functioning.
• Neurons- the cells that make up the nervous system are called neurons.
Neurons carry the electrical messages that are the "language" of the nervous
system.

48. How are Multi-Cellular
organisms organized?

49. How are Multi-Cellular
organisms organized?
• The multi cellular is organized from cell,
tissues, organs, systems and organisms. The
cells are made of organelles which carry out the
function necessary for life. Cells are the
smallest part of living thing. Tissues are created
by a group of cells. Organs are made by groups
of tissues. The organ makes systems which
operate the functions of the Organism. Systems
form Organisms.

50. • The multi cellular is organized from cell,
tissues, organs, systems and organisms. The
cells are made of organelles which carry out the
function necessary for life. Cells are the
smallest part of living thing. Tissues are created
by a group of cells. Organs are made by groups
of tissues. The organ makes systems which
operate the functions of the Organism. Systems
form Organisms.

54. Benefits of Multi-Cellular

55. Benefits of Multi-Cellular
• The advantages of being a multi cellular organism are that it has many
groups of cells, tissues and organs to perform the same functions unlike the
unicellular organisms they have one cell to carry out all the functions.

56. Benefits of Multi-Cellular
• The advantages of being a multi cellular organism are that it has many
groups of cells, tissues and organs to perform the same functions unlike the
unicellular organisms they have one cell to carry out all the functions.
• If one cell of a multi cellular organism dies it has other cells which will
carry out its function. If a cell of a single cellular organism dies the whole
organism will die because there are no other cells to perform the function.

57. Benefits of Multi-Cellular
• The advantages of being a multi cellular organism are that it has many
groups of cells, tissues and organs to perform the same functions unlike the
unicellular organisms they have one cell to carry out all the functions.
• If one cell of a multi cellular organism dies it has other cells which will
carry out its function. If a cell of a single cellular organism dies the whole
organism will die because there are no other cells to perform the function.
• The advantage of a multicellular organism over a unicellular organism is
that multicellular organisms can grow to any size because of multiple cells.
Unicellular organisms can only grow to a certain size because of limited
cells.

58. Benefits of Multi-Cellular
• The advantages of being a multi cellular organism are that it has many
groups of cells, tissues and organs to perform the same functions unlike the
unicellular organisms they have one cell to carry out all the functions.
• If one cell of a multi cellular organism dies it has other cells which will
carry out its function. If a cell of a single cellular organism dies the whole
organism will die because there are no other cells to perform the function.
• The advantage of a multicellular organism over a unicellular organism is
that multicellular organisms can grow to any size because of multiple cells.
Unicellular organisms can only grow to a certain size because of limited
cells.
• Multicellular organisms are able to complete much more complicated tasks
and are much more efficient at completing the simpler tasks. Each part of
the multicellular organism is specifically designed to perform a specific task
that they are good at it. All the parts come together and work as a whole to
function. None of this exists in a single-celled organism.

60. Explain how blood is the
“transportation system” for the

61. Explain how blood is the
“transportation system” for the
• Blood is a liquid pumped by the heart throughout the
body. Blood is a combination of plasma and cells that
float in it. Blood is a specialized body fluid that
supplies essentials substances and nutrients, such as
sugar, oxygen, and hormones to our cells, and carries
waste away from those cells. The waste is eventually
flushed out of the body in urine, feces, sweat, and
lungs (carbon dioxide). Blood also contains clotting
agents. The main function of the blood is to transport
oxygen, wastes, nutrients, minerals, hormones, blood
cells and other substances throughout the body.

62. • Blood is a liquid pumped by the heart throughout the
body. Blood is a combination of plasma and cells that
float in it. Blood is a specialized body fluid that
supplies essentials substances and nutrients, such as
sugar, oxygen, and hormones to our cells, and carries
waste away from those cells. The waste is eventually
flushed out of the body in urine, feces, sweat, and
lungs (carbon dioxide). Blood also contains clotting
agents. The main function of the blood is to transport
oxygen, wastes, nutrients, minerals, hormones, blood
cells and other substances throughout the body.

67. Parts of the Blood

68. Parts of the Blood
• The main components of blood are:
• Red blood cell- Makes up 44% of the blood and the primary function of red blood cells
is to carry oxygen from the lungs to the tissues around your body. As a secondary
function, they are also a key component in getting carbon dioxide waste from your
tissues to your lungs, where it can be breathed out.
• White blood cell- Makes up 1% of the blood and are also called leukocytes. They are
part of the immune system. They help fight against diseases and infections in the body.
• Plasma- It makes up 55% of the blood. It carries nutrients, waste products, hormones
and blood cells. Plasma brings nourishments to the heart and takes most of the CO2
from the body.
• Platelets- Makes up less that 1% and it causes blood to clot/thicken at the site of the
wound to prevent blood loss. Platelets are cell fragments without nuclei that work with
blood clotting chemicals at the site of wounds. For the clotting to occur, the Platelets
have to work together with 13 different blood clotting factors to prevent blood loss.

69. • The main components of blood are:
• Red blood cell- Makes up 44% of the blood and the primary function of red blood cells
is to carry oxygen from the lungs to the tissues around your body. As a secondary
function, they are also a key component in getting carbon dioxide waste from your
tissues to your lungs, where it can be breathed out.
• White blood cell- Makes up 1% of the blood and are also called leukocytes. They are
part of the immune system. They help fight against diseases and infections in the body.
• Plasma- It makes up 55% of the blood. It carries nutrients, waste products, hormones
and blood cells. Plasma brings nourishments to the heart and takes most of the CO2
from the body.
• Platelets- Makes up less that 1% and it causes blood to clot/thicken at the site of the
wound to prevent blood loss. Platelets are cell fragments without nuclei that work with
blood clotting chemicals at the site of wounds. For the clotting to occur, the Platelets
have to work together with 13 different blood clotting factors to prevent blood loss.

73. Disorders of the Circulatory
System

74. Disorders of the Circulatory
System
• Angina is chest pain or discomfort that usually occurs with
activity or stress. Angina is chest discomfort due to poor blood
flow through the blood vessels in the heart. Your heart muscle
is working all the time, so it needs a constant supply of
oxygen. This oxygen is provided by the coronary arteries,
which carry blood. When the heart muscle has to work harder,
it needs more oxygen. Symptoms of angina occur when the
coronary arteries are narrowed or blocked by hardening of the
fatty deposits, or by a blood clot.

75. • Angina is chest pain or discomfort that usually occurs with
activity or stress. Angina is chest discomfort due to poor blood
flow through the blood vessels in the heart. Your heart muscle
is working all the time, so it needs a constant supply of
oxygen. This oxygen is provided by the coronary arteries,
which carry blood. When the heart muscle has to work harder,
it needs more oxygen. Symptoms of angina occur when the
coronary arteries are narrowed or blocked by hardening of the
fatty deposits, or by a blood clot.

79. Disorders of the Respiratory
System

80. Disorders of the Respiratory
System
• The Respiratory system has many disorders:
• Asthma is a long-term disease that makes it hard to breathe.
Asthma can't be cured, but it can be managed. With proper
treatment, people with asthma can lead normal, active lives.
Doctors know that there are some things that make a person more
likely to get asthma. If asthma is in your family history, if you live
in a area higher air pollution and if your work in certain types of
jobs you have a higher chance of getting Asthma.
• Pneumonia is an infection of the lung that is caused different
germs, including bacteria, viruses, and fungi. When you breathe in
these germs, they can settle in the air sacs of your lungs. The
germs may grow and overcome your body's normal defenses.
After they become infected, the air sacs then fill with pus and
mucus. This swelling of the air sacs keeps oxygen from properly
reaching your blood stream.

82. Disorders of the Respiratory
System

83. Disorders of the Respiratory
System
• Lung cancer is cancer that starts in the lungs. Cancer is a disease where
cancer cells grow out of control, taking over normal cells and organs in the
body. There are two major types of lung cancer. Each type of lung cancer
grows and spreads in different ways. Each type may be treated differently.
The two major types are Non-small cell lung cancer and small cell lung
cancer. Lung cancer is usually caused by smoking – but not always.
Researchers say that smoking causes 90% of lung cancer in men and 70% of
Lung Cancer in women. Doctor say Lung Cancer can be caused by Second-
Hand smoke, Radon (a colourless and odorless gas found in soil),Asbestos
( a heat resistance mineral found in workplaces and home) and other toxic
products.

84. • Lung cancer is cancer that starts in the lungs. Cancer is a disease where
cancer cells grow out of control, taking over normal cells and organs in the
body. There are two major types of lung cancer. Each type of lung cancer
grows and spreads in different ways. Each type may be treated differently.
The two major types are Non-small cell lung cancer and small cell lung
cancer. Lung cancer is usually caused by smoking – but not always.
Researchers say that smoking causes 90% of lung cancer in men and 70% of
Lung Cancer in women. Doctor say Lung Cancer can be caused by Second-
Hand smoke, Radon (a colourless and odorless gas found in soil),Asbestos
( a heat resistance mineral found in workplaces and home) and other toxic
products.

88. Disorders in Excretory System

89. Disorders in Excretory System
• Disorders in the Excretory System:

90. Disorders in Excretory System
• Disorders in the Excretory System:

91. Disorders in Excretory System
• Disorders in the Excretory System:
• A kidney stone is a solid mass made up of tiny crystals. One or
more stones can be in the kidney or ureter at the same time.
Kidney stones are common. Some types run in families. There
are different types of kidney stones. The exact cause depends
on the type of stone. Stones can form when urine contains too
much of certain substances. These substances can create small
crystals that become stones. The stones take weeks or months
to form. Doctors do not always know what causes a stone to
form. A person with a family history of kidney stones may be
more likely to develop stones. People with urine infections,
kidney disorders and metabolic disorders have chances to get
Kidney stones.

93. Disorders in Excretory
System

94. Disorders in Excretory
System
• A urinary tract infection, or UTI, is an infection that can happen
anywhere along the urinary tract. Urinary tract infections have
different names, depending on what part of the urinary tract is
infected. Urinary tract includes Bladder, Kidneys, Ureters, and the
Urethra. Germs, usually bacteria enter the urethra and the bladder,
which causes infections in the Urinary tract. The infection spreads
throughout the Excretory System.

95. • A urinary tract infection, or UTI, is an infection that can happen
anywhere along the urinary tract. Urinary tract infections have
different names, depending on what part of the urinary tract is
infected. Urinary tract includes Bladder, Kidneys, Ureters, and the
Urethra. Germs, usually bacteria enter the urethra and the bladder,
which causes infections in the Urinary tract. The infection spreads
throughout the Excretory System.

99. How to keep you
Circulatory System healthy?

100. How to keep you
Circulatory System healthy?
• Minimize your salt (sodium) intake. Too much salt
intake may cause the development of heart disease for
people already suffering from high blood pressure.
• Get enough rest, sleep, and proper exercise.
• Eat a balanced diet. A variety of food in your daily
meals will supply the necessary nutrients your body
needs to be strong and healthy.
• Avoid fatty foods. Fatty foods contain bad cholesterol.
• Wear loose clothes to avoid restriction of blood
circulation.
• Avoid harmful drugs, cigarettes and alcohol. Alcohol
intake can increase blood pressure and react with blood
pressure medications. People who smoke and have high
blood pressure who may suffer from other diseases due
to complications.

102. How to keep your respiratory
system healthy?

103. How to keep your respiratory
system healthy?
• Periodically take big, deep breaths that will fill up and
expand our lungs with oxygen.
• It is extremely important to do some form of exercise every
day of your life. Along with helping us take in oxygen and
get our blood flowing, which is how the oxygen reaches
every cell in our body.
• Drink lots of pure water. We need to keep all of the cells in
the body hydrated. When the respiratory system becomes
dried out, it is much more prone to bacteria and infections.
• Do not smoke and try to avoid as much second-hand smoke
as possible.

105. How to keep your Excretory
System Healthy?

106. How to keep your Excretory
System Healthy?
• Drink the recommended eight glasses of water every day. This helps flush
your kidneys by forcing them to work harder. Water is the healthiest thing
to drink because all other liquids must be filtered by your kidneys.
• Exercise to help your kidneys and sweat glands work efficiently. Exercise
also can help control high blood pressure as high blood pressure is hard on
your kidneys.
• Maintain a balanced diet. The body need fibers found in cereals, fruits, and
leafy vegetables to facilitate.
• Have a regular medical check up so that you know if your excretory organs
are okay

107. Obesity Is a Problem
• We feel a bit depressed because obesity puts humans at risk of many
diseases such as Cancer, Heart attack, High blood pressure, stroke
and other diseases to small children and adults. We also understand
that obesity is a immense problem in Canada and throughout the
world and needs ti be solved.People can get obese is by having lots
of fat and calories, drinking too many drinks with caffeine, not
getting enough exercise and drinking too much alcohol. We think
that the problem of obesity is due to the personal choices of the
people. It is their problem by not eating healthy foods which is
resulting to the problem of obesity.
• The remedy of obesity is to eat healthy food, low fat food and
vegetables and fruits. Avoid eating fast food like McDonalds, KFC,
Burger King and other fast foods because they are fatty and
unhealthy.
• Obesity can also be remedied by lots of exercise. People should
exercise for at least an hour a day to burn off the fat and calories you
consume in a day. Avoiding caffeine drinks can also reduces the risk
of obesity.