Biology Dossier

Departament de Ciències Naturals
Biology 3rd ESO
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Dossier of Biology
NAME:
ACADEMIC YEAR:
3rd
of ESO CLASS:

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INDEX
 Introduction: 1st
day and 1st
activity
 Unit 1: Levels of organization:
1.1 Nutrients
1.2 Cells
1.3 Tissues
1.4 Organs
1.5 Systems
 Unit 2: Nutrition function:
2.1 Digestive system
2.2 Respiratory system
2.3 Circulatory system
2.4 Excretory system
 Unit 3: Relation function:
3.1 Nervous system
3.2 Endocrine system
3.3 Senses
3.4 Locomotors system
 Unit 4: Reproductive function

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INTRODUCTION
1. Welcome to BIOLOGY in English.
2. The Natural Science of the 3rd
of ESO has two parts:
Chemistry – Physics and Biology
3. Part one: has one mark. Part two: has a second mark. The final result is the
average. If the final result is under 5: an extra exam of Chemistry and
Biology.
4. Biology: 4 hours a week for four months.
I am a Biology teacher.
We are going to learn Biology in English.
5. Our classes will consist of:
 Reading the contents (dossier in the Net).
 Learning the vocabulary (activities, games, pictures).
 Understanding the main ideas and studying them.
 Speaking and explaining the content.
 Listening to videos and understanding them.
 Doing the laboratory practices (3 approx).
6. You have to do the following things:
 Print the dossier
 Collect all the notes, and photocopies given
 Do all the activities, exercises, drawings.
 Try to do the optional work: it shows your interest you.
 Study as much as you can
 Improve your English.
7. To evaluate this subject I will consider:
o Your class work (participation, behaviour, groups…) 20%
o Your homework and the activities (dossier) 10% , lab practices 5%
o The final exam 40% and tests 25%

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INTRODUCTION: Parts of the body

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INTRODUCTION: Organs of the body

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UNIT 1: Levels of Organization
Abiotic levels of organization (with no life)
- Subatomic level. This consists of the smallest particles of the matter, such as
neutrons, protons, electrons, etc.
- Atomic level. This consists of atoms, which are the smallest portions of a
chemical element.
- Molecular level. This consists of molecules or compounds which are the
result of the union of two or more atoms. For example, a molecule of oxygen
(O2) or a molecule of water (H2O).
The molecules which form part of living matter are known as bio-molecules,
for example the molecule of glucose.
Sometimes, a group of small molecules joined together form macro-
molecules.
Those macro-molecules joined together form cellular organelles, such as
mitochondria.

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Biotic levels of organization (with life)
- Cellular level. This consists of cells. These are the smallest units of living
matter and they can do all the functions of living beings (interaction, nutrition
and reproduction). If a living being has only one cell it is called a single-celled
organism.
- Pluricellular level. This consists of living beings which have more than one
cell. These are pluricellular organisms. These have different sublevels. From
the smallest to the biggest are as follows:
1. Tissues: are sets of specialized cells which have the same
function and the same origin. For example: the muscle tissue,
formed by packets of muscle cells.
2. Organs: are the structural and functional units of higher living
beings. They are formed of various different tissues which are
joined together to do a specific function known as an act. For
example the heart, which beats to pump the blood, consists of
muscle, nerve and conjunctive tissue.
3. Systems or apparatus: are sets of different organs which do
actions independent from each other but also are co-ordinate.
For example, the digestive apparatus which is composed of the
pharynx, esophagus, stomach, intestines, etc.
4. Organism. The complete unit of the living being.
- Population level. This includes all populations, the set of individuals of the
same species which live in the same zone and at the same time. For example,
a swarm (enjambre) of bees.
- Ecosystem level. This consists of the sets of different populations of different
living beings together with the place where they live.
The set of ecosystems which exist in the world is known as the biosphere,
which is the largest level of organisation.

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Activity: Fill the gaps
- ________ level. This consists of the smallest particles of the matter, such as
neutrons, ___________, electrons, etc.
- _________ level. This consists of atoms, which are the smallest portions of a
chemical ___________.
- _________ level. This consists of molecules or compounds which are the result of
the _______ of two or more ________. For example, a molecule of oxygen or a
molecule of water. The molecules which form part of living ________ are known as
bio-molecules. For example, the molecule of glucose. Sometimes, various or a lot of
small molecules ______ together to form ____________. These join together to
form cellular ________, such as mitochondria.
- ______ level. This consists of cells. These are the smallest units of living matter
and they can do all the functions of living _______ (interaction, nutrition and
reproduction). If a living being has only one cell it is called a single-celled organism.
- ________ level. This consists of living beings which have more than one cell. These
are pluricellular organisms. These have different sublevels. From the smallest to
the biggest are as follows.
1. _______. These are sets of specialized cells which have the same _______ and
the _____ origin. For example: the muscular tissue, formed by packets of
muscular cells.
2. ______. These are the structural and functional units of superior ______ beings.
They are formed of various different tissues which are joined together to do a
specific function known as an act. For example the heart, which beats to pump
the blood, consists of muscular, nervous and conjunctive tissues.
3. ________ or apparatus. These are sets of different organs which do actions
independent from each other but also co-ordinate. For example, the digestive
apparatus which is composed of the pharynx, oesophagus, stomach, intestines,
etc.
4. _________. The complete unit of the living being.
- _________ level. This includes all populations, the set of individuals of the same
species which live in the same _____ and the ______ time. For example, a swarm of
bees.
- _______ level. This consists of both the sets of different populations of different
beings related together and the place where they live. The set of ecosystems which
exist in the world is known as the ________, which is the _______ level of
organizaation.

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1.1 NUTRIENTS
What are living being made of? What kinds of molecules would we find inside a
living being? They can be organic and inorganic molecules grouped like this:
1. Water (inorganic molecule)
There is no life without water. In fact, more than half of our
body is liquid water.
Functions: water contributes to many of the chemical reactions in our body, for
transporting substances and regulates the temperature of the body.
It is important to drink 2 liters of water every day.
2. Mineral salts. (inorganic molecules)
Mineral salts form part of some parts of living beings,
such as the shells of molluscs (calcium carbonate) or
skeletons (calcium phosphate).
Functions: Many mineral salts are in dissolution in chemical reactions, they maintain
the salinity of the body, allow the transmission of nervous impulses or they are part
of the red blood cells (they have iron: Fe).
We can obtain mineral salts eating vegetables and fruit.
3. Lipids. (organic molecules)
Lipids include oils and fats.
The lipids have an energetic function too.
We can obtain lipids eating fried food, oil,
butter or food with fat in it.

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4. Glucids. (organic molecules)
These are also called carbohydrates or sugars. Glucids are bio-molecules made of
carbon (C), hydrogen (H) and oxygen (O).
The simplest glucids, called monosaccharides, taste sweet and
dissolve easily in water. For example: glucose, fructose. Also
are in this group saccharose ,the common sugar, (glucose +
fructose) and lactose (galactose + glucose).
A lot of monosaccharide molecules joined form a
polysaccharide. The most important ones are
glycogen and cellulose. All of them are made of long
chains of glucose molecules joined together. They
do not dissolve in water and don’t taste sweet.
Living beings obtain the energy from the glucids. In
other words, the glucids have an energetic function.
We can find them in cereals, potatos, honey or sugar, and all their derivatives.
5. Proteins. (organic molecules)
Proteins are big molecules formed by little particles called amino acids.
Proteins have different functions:
 They are an important part of cell structure
 They transport substances. For example
haemoglobin transports oxygen in blood.
 They defence us against infections.
(Antibodies, which are proteins, defend us
from viruses and bacteria)
Mostly, proteins have a structural function.
We can obtain proteins eating fish, meat, milk, eggs (animal products and their
derivatives), but also in nuts, seeds and legumes.

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6. Vitamins (organic molecules)
Vitamins can be lipids or proteins. We need vitamins
for our growth and the correct functioning of the body,
so they have a regulatory function.
They usually come from fruit and vegetables. If we
don’t have enough vitamins many illnesses can appear
such as the scurvy.
7. Nucleic acids (organic molecules)
They consist of the union of small molecules called
nucleotides.
Their function is to store information for the functioning
and development of living beings. For example the DNA
which is in the nucleus of our cells contains the instructions
for the functioning of all the cells.
We don’t need nucleic acids for a healthy diet.

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Activities:
1. Make a table indicating the different nutrients, their main characteristics and
their main functions. Take the information you need from the previous text.
2. Find from the Internet a picture of the food pyramid. Then explain its meaning
and write down the nutrients we obtain, eating the groups of food that are in there.
3. Vegetarian people don’t eat meat and fish, but they need proteins too. What can
they eat to obtain those essential nutrients?
4. Find information in the next link about fibre. Where can we find it? Why is it for?
http://www.bbc.co.uk/schools/gcsebitesize/pe/performance/0_performance_nutrit
ion_rev1.shtml
5. Find information about Organic Food and write down a personal opinion about
this topic.
6. Search in the Biology Oxford book (page 25) some ideas about what is a balanced
diet.

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1.2 CELLS
Cells are the basic structural and functional unit of all living things. Cells have
different shapes: cylindrical, spherical, star-shaped, disc-shaped… and they also
have different volume or measures.
We can basically find two kinds of cells:
 Procaryotic cells, such as a bacterium, where there is no nucleus and the
genetic material is in cytoplasm.
 Eucaryotic cells, such as algae, fungi, plants and animals, where the genetic
material is stored in the nucleus, separated from the rest of the cell.
Parts of the cell
Eukaryotic cells have three important parts:
1. The cellular membrane
The cellular membrane consists of lipids and proteins. It has different functions:
. It separates the inside of the cell from the surroundings.
. It allows various substances to pass through to the cell from the exterior but does
not allow others.
. It makes the shape of the cell.
. Plants, algae and bacteria have a cellular wall around the cellular membrane.

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2. The cytoplasm
The cytoplasm is the space between the cellular membrane and the nuclear
membrane. It consists of a liquid substance which contains solid structures called
cellular organelles. These are the following:
The cellular organelles
Ribosomes: they make
proteins.
Endoplasmatic reticulum:
stores and transports the
proteins.
Vacuoles: store
substances.
Lysosomes: destroy and
digestive substances.
Golgi apparatus: produces glucose and stores bio-molecules.
Vesicles: store and transport substances from the Golgi apparatus to the
membrane in order to expel their content.
Mitochondria: these are responsible for the respiration of the cell and obtain
energy.
Centrosome: this is related to the movement of the cell and its organelles. It is
only in animal cells.
3. The nucleus
The nucleus is a membrane, generally with a spherical shape, that separates the
cytoplasm from the inside of the nucleus where there is the DNA. DNA has the
genetic information of the cell that knows how its parts are and which function they
have to develop.

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Sumary activity!
Watch the next video: “Parts of an animal cell” and take notes if you need it
http://www.youtube.com/watch?v=Fzj6TRnXmps&feature=related
Activities
1. Find images of a prokaryotic cell and a eukaryotic cell and follow the picture with
the explanation of the main differences between them.
2. Do the same as the previous activity with an animal and a plant cell.
3. Make a table writing in two columns the relation between the different cellular
organelles and their function.
4. Make drawing of a human cell and label in it the main parts and its different
organelles.
5. Answer the following question:
What routes will a protein follow which has been made by a ribosome until it is
expelled to the exterior of the cell in a secretion?

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1.3 TISSUES:
How do cells join together and how are they organized?
Pluricellular organisms are composed of many cells. They are joined together and
increase the size of the living being and work together.
We can define tissue as groups of cells with a similar structure that do the same
type of activity.
For example, the activity of the muscular tissue is to contract specialized cells to
produce a movement.

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1.4 ORGANS AND SYSTEMS
The organs are structures that are formed by different tissues that carry out a
concrete function called action. The organs are part of the systems that constitute
the human body.
Some of the organs of our organism are: the skin, the intestines, the liver, the lungs,
the arteries, the heart, the brain or the kidneys.
The systems of our body are formed by a set of organs that act in coordination to
carry out one or several functions.
The following table shows all the systems we have in our organism relating them to
the vital functions we have as we are living beings.
Vital function System System function
NUTRITION Digestive system Transform food in nutrients
Respiratory system Exchange gases from the air
Circulatory system Transport substances and
gases through the blood
Excretory system Expel the waste substances
RELATION Nervous system Obtain information and
elaborate orders
Endocrine system Secrete hormones we need to
function correctly
Senses Take the information about
our enviroment
Locomotors system Both muscular and skeleton
systems together
REPRODUCTION Reproduction system Produce the reproductive cells
and origin a new human body

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UNIT 2: THE NUTRITIONAL FUNCTION
The nutrition is one of the most important functions a living being has. It brings you
the necessary substances you need for living and also it helps you to take away the
harmful substances your body makes and are prejudicial for your health.
Here you are a table that shows the relations about functions, systems and
processes:
FUNCTION OF
NUTRITION:
THE NUTRITION
PROCESSES:
THE SYSTEMS INVOLVED
IN NUTRITION:
Feeding To get nutrients from food the digestive system
Respiration Respiration (O2 and CO2) the respiratory system
Circulation The circulation of blood the circulatory system
Excretion The expulsion of waste of
cellular metabolism
the excretory system

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2.1. THE DIGESTIVE SYSTEM
Remember the main functions of this system:
 The digestive system transforms the food we eat in very simple substances we
call nutrients.
 The cells need these nutrients to be able to live but also they need to eliminate
the prejudicial substances from food.
Let’s study the organs involved in digestion
Activity 1: Draw the digestive system in the middle of a sheet of paper and write
the main parts with a little explanation of each one in the two sides of the drawing.
You can copy it from a book or from an image.
Activity 2: Cooperative work: Match the words of the sheets of paper and put them
in order. Then pay attention at the screen and correct it.
Part’s names characteristic
Mouth There are the processes of mastication and salivation
Incisors, canines,
premolars and molars
These are the four types of teeth human has
oesophagus The peristaltic movements pushes the food
Stomach Where the gastric digestion occurs
Pancreas Elaborate pancreatic juice which goes to the duodenum
Liver Produces the bile that is stored in the Gallbladder
Small Intestine There is the absorption of the useful substances
Ileum and duodenum These are the organs that make up the small intestine
Large intestine It formed the faeces with the remains of the digestion
Rectum The last part of the large intestine that expel the faeces
thought the anus

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The digestive process:
A: Digestion of food begins in the mouth with
chewing (mastication).
Insalivation occurs because the salivary glands
produce saliva (the first digestive juice) and it is mix
with food.
Food is physically broken into small pieces with the
teeth and tongue and then is swallowed.
B: The swallowed food travels down pharynx and a
long tube called oesophagus into the stomach.
Food is moved down the oesophagus by muscular
contractions called peristaltic movements.
C. The stomach is a flexible muscular bag about the
size of an apple. Food is mixed with the gastric juice
that is produced in the stomach.
Food is gradually turned into a liquid and it goes into the intestine in small amounts.
Liver produces bile that is stored in the gall bladder, and pancreas elaborates
pancreatic juices. Those digestive juices are released when the food enters in the
duodenum, the first part of the small intestine.
D. The small intestine is a thin tube around 6 meters long. It produces an intestinal
juice to help the final digestion. Small intestine is so ingeniously made, that it
presents an enormous surface area from which it extracts nutrients from the
mixture. This process is called absorption, where nutrients move across the small
intestine wall into the bloodstream, where they are transported to all the cells of
the body.
E. The large intestine is about 1.5 meters long, containing undigested material
including fibre, bacteria and other wastes that have been passed from the small
intestine. It's here, where water is extracted (recycled) and faeces, the waste
material, are finally eliminated by the anus.

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So, we have learnt that the digestive system is formed by:
 A digestive tube that has about 10 meters length constituted for the mouth,
pharynx, oesophagus, stomach, small intestine, large intestine and the anus.
 Digestive glands/organs with digestive juices: salivary glands (saliva), stomach
(gastric juice), liver (bile), pancreas (pancreatic juice) and small intestine
(intestinal juice).
ACTIVITY 3: Read the text and complete the missing words.
The digestive system is mainly a long tube that runs from the 1................... to the
2................... This tube is called the 3..................., or alimentary canal. The
alimentary canal is associated with the organs of the liver, gall bladder and
pancreas. These organs assist digestion by secreting 4................... that help
breaking down the food so that it can be easily absorbed by the body. The digestion
of food begins in the mouth with chewing and ends in the 5................... Any
undigested food is eliminated from the body via the anus. There are two forms of
digestion: 6..................., involving the insalivation and chewing (mastication) in the
mouth and swallowing to the stomach. Also, 7................... is the use of enzymes to
break down the food into smaller particles that can be absorbed into the body.
digestive juices - digestive tube - mechanical process - mouth -
chemical process - anus - large intestine

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ACTIVITY 4: Find information about some of the most important nutritional
disorders and write down the main characteristics of each.
ACTIVITY 5: Place the name in the correct place and make a definition of each word.
Across
2. cardia
3. pharynx
6. pancreas
8. Intestine
10. rectum
12. faeces
13. stomach
14. mouth
Down
1. peristaltic
3. pylorus
4. bile
5. gastric
7. liver
9. duodenum
11. esophagus

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2.2. THE RESPIRATORY SYSTEM
As well as nutrients, the cells in our body also need oxygen. This molecule is
essential for the process that converts glucose into energy.
The respiratory system function is to capture oxygen from air, transport it to the
cells of the body and expel the wasted gas produced (carbon dioxide).
We normally associate the word respiration with the breathing, using the lungs. But
respiration is much more complex than this and it also includes the cellular
respiration.
Cellular respiration is a process that takes place inside
the mitochondria of all the cells of our body. Taking
oxygen and glucose, they produce the energy we
need and some water. With this chemical reaction, a
toxic gas is produced, the carbon dioxide, so the cells
have to expel it.

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So, the respiratory apparatus: takes the air from the exterior, captures the oxygen,
passes the oxygen to the blood, recovers the carbon dioxide produced in the cells
and expels air rich in carbon dioxide out of the body.
The circulatory apparatus transports the oxygen to all the cells, through the blood,
and collects the carbon dioxide.
Both apparatus work together under the control of the nervous system.
The main parts of the Respiratory System, characteristics and functions:
Pharynx: Tube that connects nasal cavity
and mouth to larynx and oesophagus.
Larynx: Is a tube that routes air into proper
channels and produces the voice.
Trachea or windpipe: Is a tube that
descends from larynx into the two bronchus.
Bronchus: introduces the air from trachea to
the bronchioles. There is one bronchus in
each lung.
Bronchioles: Are smaller tubes that make a bronchial tree. At the end of those
branches there are alveoli.
Alveoli: Are tiny sacs where the oxygen from the air passes into the bloodstream
and carbon dioxide passes from blood to the air. Here is where gas exchange takes
place.
Lungs: are organs that contain bronchi, bronchioles and alveoli.

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Respiratory movements:
Air is taken in and expelled in two movements, inspiration and expiration.
The muscles involved are: the diaphragm, the intercostal and the abdominal
muscles.
- During inspiration the air enters into the lungs. The diaphragm contracts and
descends and the thoracic cage increases its volume.
- During expiration the air leaves the lungs. The thoracic cage decreases and
the diaphragm relax.
Interchanging gases or gas exchange
The bronchioles are connected to the alveoli, small sacks which are in contact with
numerous blood vessels.
The gas exchange between the air and the blood occurs easily in the alveoli. In each
alveolus, the blood releases the carbon dioxide which passes to the air, and at the
same time it takes the oxygen.
So, the blood is oxygenated when it
leaves the alveoli of the lungs and
returns to the heart through the
veins. The heart pumps the
oxygenated blood and the oxygen
reaches the rest of the body. Carbon
dioxide produced in the cells is expelled to the exterior.
Respiratory rhythm
Our cells do not always require the same amount of oxygen. During intense
physical exercise, the cells of our muscles work more and require more oxygen.
When we are asleep, the opposite occurs. Respiratory rhythm is the number of
inspirations per minute and it depends on the oxygen requirements. Normally, we
make 12 inspirations per minute. After heavy exercise, it increases to 40
inspirations per minute. The nervous system always analyses the oxygen
requirements and controls the rhythm of respiration.

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Healthy Respiratory System
If you like to play baseball, or dance, or swim, or just keep active, you will want to
keep your respiratory system in top shape. You need a strong, healthy respiratory
system.
The two things that are really good for your lungs and the rest of your respiratory
system are do physical exercise and not putting anything into your lungs that is
toxic for them.
Any activity that gets you moving is good and if it’s done outside is better.
Breathing is something that you do every minute of every day, from
the moment you are born until the moment you die. Breathing keeps
you alive. Your respiratory system works hard. Shouldn't you keep it
healthy? The most important thing is…
PATHOLOGIES of the respiratory system:
Pneumonia: is an infection of the alveoli. It can be caused by bacteria and/or
viruses. The surface area exposed to air in alveoli is reduced, so the patient may
need supplemental oxygen.
Emphysema: The delicate walls of the alveoli break down, reducing the gas
exchange area of the lungs. It can be a direct cause of death. However, the gradual
loss of gas exchange area forces the heart to pump ever-larger volumes of blood to
the lungs in order to satisfy the body's needs.
Bronchitis: Any irritant reaching the bronchi and bronchioles will stimulate an
increased secretion of mucus. In bronchitis the air passages become clogged with
mucus, and this leads to a persistent cough. Chronic bronchitis is usually associated
with cigarette smoking.
Lung Cancer: Is the most common cancer and the most common cause of cancer
deaths. Lung cancer, like all cancer, is an uncontrolled proliferation of cells.
Asthma: In asthma, periodic constriction of the bronchi and bronchioles makes it
more difficult to breathe in and, especially, out. Attacks of asthma can be by air with
irritants such as chemical fumes and cigarette smoke or by air with particles to
which the patient is allergic.

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Activities Answer the following questions:
01. Which are the two kinds of respiration?
02. Draw the respiratory system in a paper and label it. Write in it a simple
explanation of each part.
03. Which are the main parts of our respiratory system? Write them in order.
04. What part of our skeleton protects the lungs?
05. Which gases compose the air we breathe?
06. Are the two lungs of the same size? Why?
07. Which is the trajectory the air do from outside to the inside of our lungs?
Write the respiratory process by steps.
08. Why we breathe different times depending of our age?
09. Explain how inspiration and expiration occurs.
10. In what part of the lungs is the interchange of gases produced? Why is it an
area that is rich in blood vessels?
11. What do we have to do to maintain healthy our respiratory system? Write
down a list of ideas.
12. Watch the next videos and write some ideas you think are the most
important ones.
http://www.youtube.com/watch?v=hc1YtXc_84A (respiratory system)
http://www.youtube.com/watch?v=o2OcGgJbiUk
http://www.youtube.com/watch?v=KMNMP3wJ-3c (pollution and health)
http://www.youtube.com/watch?v=0g-Qc6MHKSE (air pollution)
http://www.youtube.com/watch?v=XXwpTrI74BQ&feature=related (how smoking and
drinking affects to our body).

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2.3. THE CIRCULATORY SYSTEM
The circulatory system carries blood and dissolved substances to and
from different places in the body. The heart has the job of pumping
these things around the body.
The heart pumps blood and substances around the body in tubes
called blood vessels. The heart and blood vessels together make up
the circulatory system.
What’s in blood? Composition of blood
 Red blood cells or Erythrocytes: They are not real cells
because they don’t have nucleus. They contain
haemoglobin, a molecule which holds oxygen and
carries it to cells that need it.
 White blood cells or Leucocytes: There are many different types
and all contain a big nucleus. The two main ones are
lymphocytes and macrophages. Macrophages ‘eat’ and digest
micro-organisms. Some lymphocytes fight disease by making
antibodies to destroy invaders.
 Platelets: Are cell fragments. Platelets produce fibres to form
a net that traps other blood cells to form a blood clot (to
coagulate).
 Plasma: A liquid that carries the cells and the platelets which help blood clot.
 Oxygen
 Carbon dioxide
 Hormones
 Waste (Urea)
 Nutrients

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Blood vessels
Blood from the heart gets around the body through blood vessels. There are 3
types of blood vessels:
1) Arteries are the thickest and strongest vessels because they have to carry
blood at high pressure. They carry blood away from the heart.
2) Veins have thinner walls than arteries as they carry blood at low pressure.
They are the only ones which have valves (which stop blood going in the
wrong direction). They carry blood towards the heart.
3) Capillaries are the smallest and thinnest. They have thin walls to allow
gases, glucose and wastes to diffuse in and out easily. They are in contact
with all the cells in the body. They link arteries with veins.
Activities:
Activity 1: Make a mind map about the circulatory system.
Activity 2: Describe the composition of blood in a table. Write their characteristics
and functions.
Activity 3: Make a diagram indicating the different kind of vessels and their
characteristics.
Activity 4: Fill the gaps:
Arteries take blood ______ from the heart. The walls of an artery are made
up of thick _________ walls and elastic fibres. Veins carry blood ________ the
heart and also have valves. The _________ link arteries and veins, and have a
one cell thick wall. Blood is made up of four main things ______, the liquid
part of the blood; Red Blood Cells to carry ______; White Blood cells to
protect the body from disease and _________ to help blood clot.

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Parts of the heart:
How does the Heart work? A heart beat (Diastole is filling and Systole is pumping)
1) Diastole: The heart relaxes and blood flows from the vena cava and
pulmonary veins. This blood flows into the atria.
2) Atria systole: The atria contract and the blood is pumped into the
ventricles.
3) Ventricular systole: The ventricles contract forcing the blood to leave the
heart through the aorta and pulmonary arteries.
The valves close to stop blood flowing backwards. At the same time, the
atrium relaxes and fills with blood. Then, the cycle begins again.

Biology 3rd ESO
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How the heart works? Explanation of the circulatory process
• The blood from the body that is low in oxygen (blue) returns to the heart through
the cava vein to fill the right atrium. This process is known as a diastole.
• The right atrium contracts, the tricuspid valve opens and the blood fills the right
ventricle. This process is known as an atria systole.
• The tricuspid valve closes and this prevents blood from flowing back into the right
atrium.
• The right ventricle full with blood contracts and the pulmonary valve opens.
• Blood is pumped to the pulmonary artery and to the lungs. This process is known
as a ventricular systole.
• The pulmonary valve closes to prevent blood flowing back into the right ventricle.
• From the lungs, blood oxygenated (red) arrives to the left atrium of the heart
through the pulmonary vein, a diastole process.
• The left atrium contracts, the mitral valve opens and the blood is pumped into the
left ventricle.
• The mitral valve closes to
prevent blood going back into
the left atrium.
• The left ventricle contracts, the
aortic valve opens. The blood
is pumped to the aorta artery
and goes to all the cells in our
body.
• The aortic valve quickly closes
to prevent blood from flowing
back into the left ventricle.
• The cycle begins again.

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Diseases and disorders of the blood or of the cardiovascular system:
• Anaemia:
Low levels of haemoglobin in your erythrocytes.
This inhibits the proper transport of oxygen in the body.
You feel very tired because oxygen doesn’t reach your muscles. You’d better
take a diet rich in iron.
• Atherosclerosis:
The arteries begin to lose their elasticity and plaques form in their walls.
They become narrow and reduce blood supply to regions of the body
particularly the brain and heart.
• Heart attack:
It is due to the blockage of a coronary artery which supplies the myocardium.
The cardiac muscle stops and the heart don’t function properly.
This is caused by the mounts of cholesterol and lipids called plaques, blood clots
called thrombus, or an embolism which is a blood clot that forms somewhere
else in the body. It clogs a coronary artery stopping the flow of blood.
Activities:
Activity 5: Draw a detailed picture of the heart, labelling all chambers, valves,
arteries and veins.
Activity 6: Draw the circulatory circuits in a simple way. Show the direction of
blood flow throughout the heart and body. Afterwards explain step by step how
each blood trajectory goes since it arrives to the right atrium of the heart and turn
back again.
Activity 7: Fill in the missing words.
Oxygenated blood from the lungs returns to the … (A)…. atrium of the heart inside
the … (B)…. vein. From here it enters the …(C)…. ventricle and leaves the heart in
the … (D)… (E)... to go to the body. From the body, blood returns via the (F)…
(G)….to the … (H)…. atrium, and then leaves the heart in the … (I)…… artery to go to
the … (J)….

Biology 3rd ESO
page 33
More information: Schematic Diagram of Blood circulation:
Below is a heart diagram with deoxygenated blood in blue and oxygenated blood in
red flowing through the heart.
Blood composition:
http://www.youtube.com/watch?v=R-sKZWqsUpw
Blood Clotting:
http://www.youtube.com/watch?v=uBvpE5ia2LE&feature=endscreen
Different kinds of blood vessels:
http://www.youtube.com/watch?v=CjNKbL_-cwA
Heart and Blood circulation:
http://heart-disease.emedtv.com/off-pump-cabg-video/overview-of-the-heart-video.html

Biology 3rd ESO
page 34
BLOOD DONATION:

Biology 3rd ESO
page 35
2.4 THE EXCRETORY SYSTEM
The nutrients that feed our body's cells produce waste substances. These
substances are toxic, so they must be expelled from the body.
The cells release the waste substances into the blood. The blood must, therefore,
be purified to prevent the substances from accumulating in the bloodstream.
Excretion is the name of the process that involves eliminating the waste substances
from the blood. It is really a cleaning process in which the blood is filtered, removing
all of the dangerous substances it may contain. Excretion produces urine and sweat.
2.4.1. Urinary system:
Contaminated blood enters into the kidneys through the aorta artery and especially
through the renal artery. Inside the kidneys, blood is filtered and cleaned and then
comes back to the circulatory system through the renal vein and then to the cava
vein. Waste products are eliminated in the form of urine.
Urinary organs:
Kidneys are two organs at the back of the abdomen (one on each side). They are
the main organs responsible for filtering the blood and for getting rid of all the
waste substances by making urine. Each kidney is made up of thousands of small
functional units known as nephrons. Nephrons filter the blood to produce urine.
Ureters are two tubes that connect the kidneys with the Bladder, an elastic sac
where urine is collected before it is expelled outside the body through the Urethra.

Biology 3rd ESO
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The production of urine:
Urine is the excretion liquid that contains the toxic substances which must be
expelled from the body. As you can see in the following table it consists mostly of
water.
Composition (%) of plasma and Urine
In urine In plasma In urine In plasma
Water 95 90 Ammonia 0.04 0.0001
Urea 2 0.03 Glucose 0 0.1
Uric acid 0.05 0.004 Proteins 0 8
Creatinine 0.075 0.001 Salts 1.56 0.72
In this table you can see that urine has a greater concentration of some toxic
substances (urea, uric acid, creatinine and ammonia) and a lesser concentration of
other substances that can be used by the body (proteins and glucose). This shows
how the forming of urine is not simply a filtering process, but that it is a very
selective process:
1) First, the blood enters in the kidney and nephrons keep the liquid part and
small substances that pass through the rest of the nephron.
2) Some substances of the liquid are recovered, returning to the blood: amino
acids, glucose and water are recovered. Waste substances are not
reabsorbed, and together produce urine.
3) The urine is collected in the renal pelvis and taken, via the ureter, to the
bladder where it is expelled from the body.
2.4.2. Sweat Glands:
The skin’s sweat glands of the skin collaborate in excretion by producing sweat.
Sweat is a liquid which has a similar composition to urine, and it is produced by the
filtering of the blood that goes to the skin. When the outside temperature is high,
sweating increases. As it evaporates from the skin, the skin is refreshed.

Biology 3rd ESO
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Activities:
Activity 1: Draw the excretory apparatus and label the picture. Show the veins and
arteries which take the blood to and from the excretory apparatus.
Activity 2: Where is urine produced?
Activity 3: What other organs of the body are responsible for excretion? Why?
Activity 4: What is sweat? Explain the two functions of sweat.
Activity 5: Describe the nephron’s general function.
Activity 6: Explain the excretion process in the excretory apparatus, from the
filtering of the blood to the expelling of the urine.
Activity 7: What happen if the kidneys don’t work correctly?
Activity 8: Why do you think it is important for us to drink a lot of water? How
much do you think we should drink?
Activity 9: Discuss the following statement: “The urethra is different in men and in
women”.

Biology 3rd ESO
page 38
UNIT 3: THE RELATION FUNCTION or INTERACTION FUNCTION
Human beings react to and interact with their surroundings. Several systems are
involved in interaction:
The nervous system: Receives information from outside and works out suitable
responses. It also coordinates and unites all the body functions.
The endocrine system: Is made up of glands, special organs that secrete substances
(hormones) that have different effects on the body.
The sensory organs or Senses: Pick up information from the surroundings and
enable the body to adapt and survive. (Oral presentations notes)
 Hearing
 Sight
 Touch
 Taste
 Smell
The locomotors system: Is responsible for a person’s movement. Is formed by:
 The skeleton (Oral presentations notes)
 The muscles

Biology 3rd ESO
page 39
3.1 THE NERVOUS SYSTEM
1. Make a mind map explaining the parts of the nervous system.
2. Draw a neuron and label each part.
3. Draw the brain. Label the three main parts in it.
4. Make a table explaining the functions of the main parts of the brain.
5. Draw the different regions of the cerebrum. Where is each sense detected in the
brain? Where is control of our movements?
6. What can we do to have a healthy brain?
7. How does the reflex action work? And a voluntary action?
8. Explain the synapse process.
9. How is our nervous system protected?
10. Find information about two diseases related with the nervous system.
Search the information you need in:
The Internet or the Biology Book (Oxford) or Links:
Introduction: http://www.youtube.com/watch?v=NL1S0AhYyFw
Divisions of the Nervous System:
http://www.youtube.com/watch?v=dOYOdJG0E0s&feature=results_vide
o&playnext=1&list=PL25AE732D9E27096D
Neurons: http://www.youtube.com/watch?v=CMnDiepv5Os
Quick trajectory information-action:
http://www.youtube.com/watch?v=xRkPNwqm0mM
Synapses:
http://www.youtube.com/watch?v=HXx9qlJetSU

Biology 3rd ESO
page 40
3.2 THE ENDOCRINE SYSTEM
The endocrine system is a group of special glands that release hormones (chemical
substances) directly into the bloodstream. Glands are organs that produce and
secrete hormones to control bodily processes.
Hormones activate cells to start, stop, increase or decrease specific functions. They
coordinate and regulate different organs so that our body functions correctly.
Hormones are secreted in such small quantities that even a slight change in their
concentration can cause big changes in the body.
The endocrine system follows commands from the brain:
I. Neurons in the brain send signals to the gland.
II. The gland then releases (liberates) different stimulating hormones.
III. Hormones travel through blood around the body.
IV. Specific organs recognize the hormone with specific receptors.
V. Hormones change the way the organ works.
The concentration of the hormone in the blood
increases with time, and when it is very high the
hormone acts on its gland to stop the liberation (this is
called negative feedback).
Liver and kidneys are the major organs that degrade hormones; breakdown
products are excreted in urine and faeces.

Biology 3rd ESO
page 41
The endocrine glands and their hormones:
Hypothalamus
A region of the brain just above the pituitary gland, that functions as the main
control endocrine centre for the autonomic nervous system by regulating sleep
cycles, body temperature, hunger, thirst, etc., and regulates various activities in the
body connected with metabolism, including the maintenance of water balance.
One of the most important functions of the hypothalamus is linking the nervous
system to the endocrine system via the pituitary gland. The hypothalamus controls
the action of the pituitary gland by secreting neurohormones.
Pituitary Gland or Hypophysis
The pituitary gland, which is located in the centre of the skull, in the base of the
brain, just behind the nose, is about the size of a pea. It is an important link
between the nervous system and the endocrine system and releases many
hormones.
It is the master endocrine gland affecting all hormonal functions in the body.
The pituitary gland releases different hormones such as growth hormones
(substances that stimulate or control the growth of our body), stimulating
hormones (regulate activity in other glands) or oxytocin that contracts the muscles
of the uterus during birth.
These are then circulated in the blood to a variety of the body's tissues, including
other endocrines.

Biology 3rd ESO
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Adrenal Glands or Suprarenal Gland
The adrenal glands are a pair of glands that secrete hormones directly into the
bloodstream. They are the body's first line of defence and respond to physical and
emotional stress. The adrenal glands are on the top of the kidneys. The hormones
secreted are called steroids. Some important steroids are:
- Adrenaline: prepares the body’s muscles for work
(like the sympathetic nervous system).
- Cortisol and Aldosterone: maintain salt levels in the
blood and blood pressure; help control kidney
function and fluid concentrations in the body.
Thyroid Glands
The thyroid gland is shaped like a butterfly in the neck. The thyroid gland secretes
hormones which regulate energy, and emotional balance. When the rate of
production is excessive, the results can be weight loss, anxiety, or even emotional
disturbance. If the rate of production is excessively low, a slowing of bodily
functions may result. It secretes
thyroxine and triiodothyronine.
Parathyroid Glands
The parathyroid glands, located behind
the thyroid, control the blood-calcium
and phosphorus level. If we don't have enough calcium for the normal functions,
the body will take it from the bones, causing them to easily fracture. Too much
calcium may cause a weakening of muscle tone and kidney stones. It secretes: the
parathyroid hormone.

Biology 3rd ESO
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Thymus
An organ of the lymphatic system located behind the upper
sternum. Lymphocytes cells (a kind of white blood cell)
develop and mature in the thymus before entering the
circulation. It is present in most young vertebrates for the
normal development of immunological function (defense),
and it tends to disappear or become rudimentary in adult
vertebrates.
Pancreas
The pancreas is a long gland which lies across and behind the stomach. This gland
secretes digestive juices which break down fats, carbohydrates, proteins and acids;
it also secretes bicarbonate, which neutralizes stomach acid as it enters the
duodenum. So the pancreas is a digestive exocrine gland. But, the pancreas is also
considered an endocrine gland because some cells in the pancreas secrete
hormones which regulate the level of glucose in the blood. It secretes hormones
(glucagon and insulin) into the bloodstream.
Insulin controls the amount of glucose
is in the blood and regulates the use
of glucose in all the body tissues
except the brain. Insulin is released
when blood levels of glucose are
rising. If the pancreas fails to produce
insulin or secretes it in low quantities,
the result is a serious disease called
diabetes mellitus.
Glucagon is released when glucose
levels in the blood are low and it
stimulates the liver to release glucose into the blood.

Biology 3rd ESO
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Ovaries
The ovaries are a pair of oval glands which lie on either side of the uterus and just
below the opening to the fallopian tubes. In addition to producing ovum, the
ovaries produce female sex hormones called oestrogens and progesterone.
Secretion of oestrogens begins at puberty and stimulates maturation of the female
reproductive system and development of the secondary sex characteristics.
Progesterone is released in establishing the menstrual cycle.
The female, unlike the male, does not produce the
sex cells (egg or ovum). A baby girl is born with
about 60,000 of these cells, which are contained in
the ovaries. Each of these cells may have the
potential to mature for fertilization.
Testes or testicles
The testes are two egg-shaped male reproductive
organs located in the scrotum. They produce sperm
and the male hormone, testosterone. The testes of
the male begin to produce testosterone at puberty.
Testosterone promotes maturation of the male
reproductive organs, development of secondary sex
characteristics, and production of sperm by the
testicles.
Activities:
1. Read, understand and underline the most important ideas and words in the
previous explanations.

Biology 3rd ESO
page 45
2. Label the main endocrine glands in the following drawing:
3. Complete the following table:
Endocrine gland Location Hormones Effect
… … … …
4. Find information on three important endocrine diseases and write them
down.

Biology 3rd ESO
page 46

Biology 3rd ESO
page 47
AT THE END OF UNIT 3 YOU SHOULD KNOW… (for the exam)
The nervous system:
 draw and label a neuron
 draw and label the encephalon = brain
 functions of the brain=encephalon’s’ parts
 reflex action, voluntary action
 regions of the cerebrum
 explanation of the nerve impulses and synapses and draw it
 parts of the nervous system
 Structures that protect the nervous system.
The endocrine system:
 locate and label the main endocrine glands
 the main hormones produced by the endocrine system and the effects
they have on the body

Senses: (Oral presentations)
 Hearing: draw and label the parts of the ear, functions and how hearing
is produced.
 Sight: draw and label the parts of the eye, explain the functioning.
 Touch: learn the layers of the skin and the functioning.
 Taste: learn the four flavours, where are they detected and the
functioning.
 Smell: explain where and how we detect the different smells and the
functioning.
The locomotors system: (Oral presentations)
 The skeleton: learn and label the main bones in our body, types of
bones, functions of the skeleton.
 The muscles: learn and label the main bones in our body, types of
muscles, functions of the muscles.

Biology 3rd ESO
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UNIT 4: THE REPRODUCTIVE FUCTION
Reproduction is essential to ensure the survival of a species, so that new individuals
will replace those who die.
Characteristics of human reproduction
Human reproduction is sexual. This means that:
 A new individual is formed from one cell that combines the genetic
information from the mother and from the father.
 It needs the formation of different specialized cells known as gametes. The
male gamete is called the spermatozoid (located in the testicles) and the
female gamete is called ovum or egg (located in the ovaries).
The union of these cells is known as fertilization. This union makes a fertilised egg
called a zygote.
Afterwards this zygote becomes an embryo inside the uterus of the female
beginning the period known as pregnancy which ends in the birth of the new being.

Biology 3rd ESO
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Sexual characteristics in men and women
Primary sexual characteristics: Characteristics present at birth, the female genitalia
and the male genitalia.
Secondary sexual characteristics: Characteristics which appear with maturity, like
puberty, and are the result of the action of sexual hormones.
- In girls (female): The ovaries start to produce mature eggs, and oestrogen
and progesterone hormones. These hormones cause the development of
pubic hair and hair under the arms, the distribution of body fats, the
development of mammary glands and menstruation.
- In boys (male): The testicles start to produce sperm and the hormone
testosterone that causes: the development of pubic hair, the beard and hair
over a large part of the body, an increase of the bones and muscle mass,
change of voice and the increase in size of the genitals.
There are also common psychological changes: a desire to want more freedom, to
feel more self-sufficient, to feel people around don’t understand you, to belong to a
group, to be interested in one’s own sexuality...

Biology 3rd ESO
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The reproductive cells
Ovum or egg Sperm or spermatozoid
Is the female gamete Is the male gamete
It is a very large and round cell (visible to the
naked eye)
It is a very small cell with 3 parts:
head, body and tail or flagellum
It is immobile It is mobile
It contain reserve nutrient supply to feed the
zygote the first few days
It can live for three days inside the female
genital apparatus
Women have all their ovum inside ovaries at
birth, and these are the only ones they will
have for their entire life
Men don’t have all the sperm stored. They
produce sperm during life
Gametes have 23 chromosomes, and one is the sexual chromosome, which is an X or Y.
Sperm determine the sex of the future child. This is because ovum is always X and sperm
can be X or Y.
If the fertilization is between an ovum (X) and a sperm (X), the child will be a girl (XX).
If the fertilization is between an ovum (X) and a sperm (Y), the child will be a boy (XY).

Biology 3rd ESO
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Female reproductive system
The ovaries: There are two ovaries that produce the female sexual hormones.
Inside them there are all the eggs or ovum. Each month, an ovum or egg matures
and is then released through the fallopian tube.
The fallopian tubes are two channels which join the ovaries to the uterus and
collect the mature eggs. Here is where fertilization takes place.
The uterus or womb is a cavity which is prepared for a fertilized ovum and for
housing the embryo (gestation) so that it can develop during the nine months of
pregnancy.
The vagina is an elastic channel which connects the uterus to the outside. It has
glands that secrete lubricants to protect and to make it easier for the penis to enter.
The vagina opens to the exterior via the vaginal orifice, just behind the urethral
orifice.
The vulva is the external female sex organ. It has folds of skin which form lips. In
between them is the clitoris, a sensitive organ with erectile tissue.
Once an ovum leaves the ovary, it goes to the
fallopian tube where it stays for a short period
of time during which it may be fertilized or it
will die.

Biology 3rd ESO
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Male reproductive system
There are two testicles that make the spermatozoids and the male sexual
hormones. They are housed in a sack of skin known as the scrotum.
The epididymis is located above the testicles and it is where the spermatozoids
mature.
The vas deferens is a channel where the spermatozoids travel to the seminal
vesicles.
Seminal vesicles: Where spermatozoids are stored and secrete many of the
substances found in semen. Semen is the fluid that contains spermatozoids,
glucose, mucus and other substances.
The prostate secretes substances that protect sperm.
The urethra is the tube that runs from the bladder and seminal vesicles to the
opening at the head of the penis. Sperm and urine leave the body through this
conduct.
The penis is a spongy organ whose mission is to deposit the spermatozoids inside
the vagina.

Biology 3rd ESO
page 53
Internet activities
Read, understand and take notes of the main ideas from the information below.
Find and add images to illustrate your explanations.
1. Draw and label the male reproductive apparatus. Write down the
characteristics of each part. (Click on the words to get the information you need).
http://kidshealth.org/misc/movie/bodybasics/male_repro.html
http://quizlet.com/9562/male-reproductive-parts-and-functions-flash-cards/
2. Check yourself! Evaluate yourself labelling the picture:
http://www.kscience.co.uk/revision/reproduction/male/malelabel.htm
3. Draw and label the female reproductive apparatus. Write down the
characteristics of each part. (Click on the words to get the information you need).
When you have finished, click on the menstrual cycle. Listen, read and go over this
cycle. Afterwards take note, following each step, of the process that occurs.
http://kidshealth.org/misc/movie/bodybasics/bodybasics_female_repro.html
4. Check yourself! Evaluate yourself labelling the picture:
http://www.kscience.co.uk/revision/reproduction/female/femalelabel.htm
5. Match each reproductive organ with its function.
http://www.kscience.co.uk/revision/reproduction/functions.htm
6. True or false?
http://www.kscience.co.uk/revision/reproduction/reproduction_test.htm
7. The changes during puberty.
http://www.kscience.co.uk/revision/reproduction/puberty.htm

Biology 3rd ESO
page 54
8. Find extra information about:
- Contraceptive methods: barrier methods, chemical methods, surgical
methods, examples of each one.
- Infertility: Definition, causes, consequences...
- Artificial reproduction: Types, explanation, illustrate the process...
- Twins: the same or different eggs and sperms.

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