Download The organization of the human body

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The organization
of the human body
FIND OUT ABOUT
• Levels of organization.
• The chemical composition of
living things.
• Cells: the basic unit of living
things.
An implant in the
inner ear stimulates
nerve fibres that
convert acoustic
signals into electrical
signals.
• Prokaryotic cells.
• Eukaryotic cells.
• Cell organelles and structures.
• Human tissue.
• Organs and organ systems.
KNOW HOW TO
• Observe animal cells under the
microscope.
• Identify cells and cell structures
in micrographs.
Artificial blood
runs through
tubes. The blood
is made with
nanoparticles.
Like real blood,
nanoparticles bind
to oxygen and
carry it
throughout the
body.
WORK WITH THE IMAGE
• Ask a classmate about parts of this prototype: What is ...
like? What does ... do?
• Describe a feature of the bionic man: It is like ... It
converts/enables/sends ... Your classmate names the part.
• Why doesn't Rex have organs and organ systems?
• Compare the bionic man’s face with the human face that
served as a model.
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HOW DO WE KNOW?
Who is Rex, the bionic man?
Rex, a robotic exoskeleton, is a prototype designed by a team of robotics experts.
All Rex's organs were created in a laboratory. They show the advances being made
in medical technology to replace certain body parts.
GIVE YOUR OPINION Do you think it will be possible to build a bionic person exclusively with
artificial organs? Why? / Why not?
A camera in Rex’s
glasses sends images to
microchips located in an
artificial retina. This
retina is the same as
those implanted in
patients.
The artificial
trachea is like
those implanted in
cancer patients.
Internal organs, such as the pancreas,
spleen and kidneys, are not yet fully
developed technically.
The first fully artificial kidney could
become available for human trial in
2017. This could eliminate dialysis in
patients with kidney disease.
The heart is an artificial valve
that pumps blood throughout
the body. It was designed for
use in patients waiting for
heart transplants.
Robotic fingers
can bend at the
joints and hold
objects. The force
they can exert
varies.
STARTING POINTS
• What basic units are living things made up of?
• What types of cells are bacteria made up of?
• How are organ tissues different from organs?
Prosthetic legs respond to electrical
impulses and enable movement.
• What are life functions? Name an organ and a
system that are involved in each life function.
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LEARNING OBJECTIVES
1
Levels of organization
• Describe the levels of
organization in living things.
• Define bioelement and
biomolecule.
All living things have a structural and functional organization. Each
level of organization helps to build the next level. The lower levels
are very simple while the upper levels become more complex.
Going from the least complex to the most complex, the levels of
organization in humans are:
Atom. The smallest component of the chemical elements that make up living things
(bioelements), primarily carbon (C), oxygen (O), hydrogen (H), nitrogen (N),
phosphorus (P), sulfur (S), calcium (Ca), magnesium (Mg) and sodium (Na).
Molecule. A group of two or more atoms joined together chemically.
The molecules that make up living things are called biomolecules.
Organelle. A group of biomolecules that work
together to form cell structures, such as
membranes, ribosomes and mitochondria.
Cell. A group of organelles
and structures. A cell is the
simplest level of life.
Organ. A group of different tissues that work together
to carry out a specific function. Examples include the
bones, kidneys and heart.
Organ system. A group of similar or different organs that
work together to carry out life functions. Examples include
the skeletal system and the musculoskeletal system.
Organism. An independent living thing made up of
organ systems that can carry out all the life functions..
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Tissue. A group of
specialized cells that
work together to perform
a specific function.
Examples include bone
tissue, muscle tissue and
nervous tissue.
The organization of the human body 2
1
The chemical composition of living things
WORK WITH THE IMAGE
Bioelements join together to form biomolecules. These can be
classified into two types: inorganic or organic.
1 Describe a level of
organization: It's a group of
biomolecules. Your classmate
identifies it: It's an organelle.
Inorganic biomolecules
They are found in living and non-living things.
• Water. The most abundant substance found in living things. It
makes up about 65% of the human body, but the exact amount
varies from one organ to another; for example, the brain contains
more water than bone. Water is also the main component of cells
and body fluids like blood.
ACTIVITIES
2 Match each of these with a
level of organization:
erythrocytes, blood,
pancreas, lipids.
• Mineral salts. Substances that can be found in living things in the
form of dissolved ions, such as a sodium ion (Na +) and potassium
ion (K +), or precipitated as crystals, such as phosphate and calcium
carbonate.
3 Make a table to show the
four major types of organic
biomolecules and the
macromolecules created
when they join together.
Organic biomolecules
They are unique to living things and contain significant amounts of the
chemical element carbon.
Fatty acids
Monosaccharide
Glycerol
Disaccharide
Polysaccharide
Fat
Carbohydrates. Monosaccharides are composed of
one molecule, for example, glucose. Disaccharides, such
as sucrose or maltose, are formed when two
monosaccharides are joined. Polysaccharides, such as
cellulose or glycogen, are formed when many
monosaccharides are joined.
Lipids. These molecules vary widely in chemical structure.
Lipids include fats, phospholipids and cholesterol. Fats
are the simplest lipid and can be broken down into fatty
acids and glycerol (a sugar alcohol).
Protein
DNA
Amino acids
Proteins. These large biomolecules (macromolecules) are
composed of many smaller molecules called amino acids.
Some important human proteins are collagen,
haemoglobin and antibodies.
Nucleotide
Nucleic acids. These macromolecules are composed of
smaller ones called nucleotides. There are two types: DNA
(deoxyribonucleic acid) and RNA (ribonucleic acid).
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LEARNING OBJECTIVES
3
Cells: the basic unit of living things
• Define cell and describe its
function.
All living things, from the simplest to the most complex, are made up
of cells. The cell is the simplest living unit that can carry out the life
functions of nutrition, interaction and reproduction. It is the basic unit
of all living things:
• It is the structural unit because it forms all structures.
• It is the functional unit because it carries out life functions
internally.
• It is the biological unit because it contains the genetic material of
the individual.
• It is the basic unit because all cells come from a pre-existing cell
through the process of cell division.
Living things can be made of one cell or many cells:
DID YOU KNOW?
A micrometre or micron is one
millionth of a metre:
1 μm = 0.000 001 m
A nanometre is one billionth of
a metre:
1 nm = 0.000 000 001 m
• Unicellular organisms. Microscopic living things are made up of
one cell. Examples can be found in the Monera kingdom (bacteria),
in the Protista kingdom (protozoa and unicellular algae) and in the
Fungi kingdom.
• Multicellular organisms. Generally, macroscopic living things are
made up of many cells. Their organization is complex. Examples can
be found in the Protista kingdom (algae) and in the Fungi, Plant and
Animal kingdoms.
The human body contains billions of cells. Adults have over 200
different types of cells. Each cell type has a specific shape, size and
function. There are many beneficial bacteria in the human body. They
are involved in processes like digestion, immunity and growth. For
these reasons, the human body is called a complex ecosystem.
Sperm: the head is about 3 µm
in diameter.
Enterocyte:
about 10 µm in
diameter.
Muscle cell:
between 10 and 100 µm
in length.
WORK WITH THE IMAGE
1 Describe the size of a cell: It
is about ... It is between ...
Your classmate names the
cell.
2 Ask about the cells: Which is
the largest/smallest/longest?
What relationship do you see
between its size or mobility
and its function?
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Erythrocyte:
8 µm in diameter.
Fibroblast:
between 20-30 µm
in diameter.
Neuron: up to
several centimetres
long.
The organization of the human body Life functions in cells
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WORK WITH THE IMAGE
Cells perform three life functions: nutrition, interaction and
reproduction.
3 Work with a classmate to
• Cellular nutrition consists of all the processes in which cells
obtain the matter and energy necessary to perform life functions.
To do this, cells take in substances, called nutrients, from the
outside. Nutrients are used for energy and to obtain the substances
necessary for growth and building or repairing structures.
Once inside the cell, the nutrients undergo a series of chemical
processes. These chemical processes are called cellular
metabolism. There are two types of metabolic reactions:
catabolism and anabolism.
describe the two types of
cellular metabolism. Use
these words: In this process,
simple/complex substances
are broken down/
synthesized to produce
energy/complex substances.
This process produces/
requires energy.
• Cell interaction enables cells to get information from their
environment and communicate with other cells.
Catabolism
Complex organic
substances
Simple
substances
Anabolism
Simple
substances
Energy
Energy
Complex
organic
substances
• The destructive phase of metabolism.
• The constructive phase of metabolism.
• The energy produced is used to synthesize new
molecules for reproduction and for cell function.
• The complex molecules produced are used in growth
and structural repairs.
ellular reproduction is the process by which a parent cell
• C
divides into two or more new cells, called daughter cells.
In unicellular organisms, cell division reproduces an entire
organism. The new individual is identical to the parent. As a result,
there is an increase in population.
In multicellular organisms, cell division results in an increase in
the number of cells that make up an organism. This increase is
reflected in the growth of the organism or the repair of damaged
or lost parts.
ACTIVITIES
4 Explain the difference between unicellular and
multicellular organisms.
5 Draw four different types of cells. Label the main
differences.
6 Draw a cell. Your classmate guesses the type.
Take turns.
7 If you had to design a cell that could have a lining,
what shape would you choose?
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LEARNING OBJECTIVES
4
Prokaryotic cells
• Compare prokaryotic cells and
eukaryotic cells.
• Describe the main differences
between the two types of cell
organization.
Prokaryotic cells have a simple structure and are generally much smaller
than eukaryotic cells. Prokaryotes have three main characteristics:
• No nucleus. Genetic material is dispersed in the cytoplasm.
• Ribosomes are the only organelles.
• The cell membrane is usually covered by a cell wall.
Bacteria are prokaryotes and consist of a single cell. They belong to the
Monera kingdom. Evidence of bacterial life on the Earth has been found
in rocks 3.8 billion years old.
Cell membrane. It surrounds the
cytoplasm. The exchange of
substances takes place here.
Bacterial chromosome. A
circular DNA molecule that
contains genetic material.
Cell wall. The thick, rigid layer
around the cell membrane. It
protects the bacteria and gives
it its shape.
Ribosomes. Organelles that
carry out protein synthesis.
Appendices. Structures like
flagella and fimbriae. Flagella
are involved in movement.
Fimbriae are shorter and more
numerous. They enable bacteria
to adhere to a surface.
Bacterial capsule. A thick outer
covering on some bacterial cells.
It promotes adhesion and protects
the cell.
WORK WITH THE IMAGE
1 Ask questions about the parts of prokaryotic and
Optical microscope
eukaryotic cells: Which part of the cell ...? Your
classmates identifies the part and the type of cell.
Eyepiece
Objectives
Electron microscope
Electron gun
(electron source)
2 The development of microscopes has enabled
direct observation of biological structures. Find out
about these two types of microscopes. Which is
the oldest type? Which enlarges an image more?
How does each work? It uses ... to ... Specimen
Magnetic lenses
Specimen
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Light source
Optical binocular
The organization of the human body 5
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Eukaryotic cells
Eukaryotic cells are more complex and generally larger than
prokaryotic cells. Their size can range from 10–100 μm to several
centimetres. Eukaryotic cells are found in human beings, animals and
plants. All eukaryotes have three structures:
Structure of a cell membrane
Carbohydrate
• Cell membrane. This membrane surrounds the cell and enables
the exchange of substances with the outside environment. The
membrane consists of two layers of phospholipids, with cholesterol
and diverse protein molecules distributed throughout. This type of
membrane is called a fluid mosaic structure because the elements
move and change position.
• Cytoplasm. This substance fills the space between the cell
membrane and the nucleus. The cytoplasm contains:
Protein
Phospholipids
– Hyaloplasm. The fluid component of the cytoplasm.
– Organelles. Cellular structures that carry out different functions.
– Cytoskeleton. Protein fibres involved in movement, internal
organization and cell division.
• Nucleus. This spherical structure contains the genetic material that
controls cellular function. It is surrounded by a double membrane
called the nuclear envelope. The membrane has tiny holes called
nuclear pores. They regulate the exchange of substances with the
rest of the cell. The nucleus contains the nucleoplasm, chromatin
and nucleolus.
Nuclear pores
Nuclear envelope
ACTIVITIES
3 Draw this animal cell as
seen under the electron
microscope. Label the
membrane, cytoplasm and
the nucleus.
Nucleolus. A round, dense
structure made up of RNA and
proteins. It is only visible when a
cell is not dividing. Cells may
have one or several nucleoli.
4 Compare prokaryotic and
Nucleoplasm. The fluid
found in the nucleus.
Chromatin. A combination of DNA
and protein makes up the genetic
material in the nucleus of a cell. In cell
division, chromatin condenses into
chromosomes.
eukaryotic cells. Describe
two structures that they
have in common and three
structures that are
different. Make a Venn
diagram.
5 Debate. What are the
major advantages of each
type of cell? Form two
teams: prokaryotes and
eukaryotes.
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LEARNING OBJECTIVES
• Describe the structure and
functions of organelles and
other structures of eukaryotic
animal cells.
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Cell organelles and structures
Organelles are tiny structures in the cytoplasm. Some are surrounded
by membranes; others have no membranes.
Mitochondria. Oval-shaped organelles with
two membranes. The outer one is smooth while
the inner one folds towards the centre, forming
the mitochondrial cristae. Through cellular
respiration, mitochondria produce most of the
energy of a cell.
Vesicles. Small, rounded organelles that store,
transport or digest cellular substances.
Vesicle
Lysosomes. Rounded vesicles produced by
the Golgi body. They contain hydrolytic
enzymes involved in intracellular digestion.
Endoplasmic reticulum (ER). A network of
interconnected membranous sacs and channels.
There are two types:
• Rough ER. This type is connected with the
nuclear envelope. Many ribosomes are
attached to it. It is involved in the synthesis
and transport of proteins to the Golgi body.
• Smooth ER. This type has no attached
ribosomes. Lipids (fats) are synthesized here.
WORK WITH THE IMAGE
1 Ask questions about the
organelles: Which are
surrounded by membranes/
involved in ...?
2 Describe the function of an
organelle: It produces/stores/
transports ... Your classmate
identifies the organelle.
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Golgi body or apparatus. Flat,
membranous sacs arranged in
layers. This organelle stores,
processes and packages
substances received from the
endoplasmic recticulum. Then,
secretory vesicles transport the
substances out of the cell.
The organization of the human body Ribosomes. Non-membranous organelles
made up of RNA and proteins. They are
found free in the cytoplasm or attached to
the rough ER. They are involved in protein
synthesis.
1
Centrosome. This organelle consists of two
centrioles: cylindrical structures composed
of protein microtubules. The centrioles are
perpendicular to each other and surrounded
by other microtubules. During cell division,
the microtubles form star-shaped asters that
help to manipulate chromosomes.
Centrosomes participate in mitotic spindle
formation when a cell divides.
Ribosomes
Cilia and flagella. Cilia are short and
abundant. Flagella are long; usually only
one or two are present. These
cytoplasmic projections are involved in
cell movement.
Cytoskeleton. A network made up
of different types of protein filaments.
It maintains the shape of the cell and
facilitates the movement of the cell,
organelles and internal vesicles. It is
also involved in chromosome
organization during cell division.
KNOW HOW TO
Observe animal cells under the microscope
The lining of the mouth provides a good source of buccal
epithelial cells for observation.
1. Obtain a sample. Scrape the inside of your cheek
with a toothpick or cotton swab.
2. Fix the slide. Smear the toothpick or cotton swab
across a glass slide. Add a drop of water and pass the
slide over a flame a few times to fix the cells to the slide.
3. Stain the sample. Add a few drops of methylene
blue and wait three minutes. Cover with a cover slip.
Remove excess stain from the sides with a paper towel.
4. Place the slide under the microscope and observe.
ACTIVITIES
3 Draw and label the cells and their structures.
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LEARNING OBJECTIVES
7
• List the characteristics and
functions of tissues.
• Identify the cells that form
tissue.
Human tissue
A tissue is a group of specialized cells that work together to perform a
specific function. The branch of biology that studies the tissues of
organisms is called histology. Tissue can be grouped into four types:
epithelial, connective, muscle and nervous.
WORK WITH THE IMAGE
Epithelial tissue
1 What type of tissue is being
Epithelial cells are generally polyhedral in shape. They are closely
packed together and arranged in layers. There are two main groups:
covering epithelia and glandular epithelia:
described?
2 This is epithelial tissue from
the uterus. What type is it?
Discuss with a classmate.
• Covering epithelia. This tissue covers internal and external body
surfaces. It protects these surfaces and regulates the exchange of
substances. The type varies depending on location:
– Epidermis. This type forms the outer layer of human skin. It
consists of many layers of cells.
– Mucous membrane. This tissue protects internal cavities such as
the digestive and respiratory tracts.
3 Why are epithelial tissues
arranged in layers?
4 Name a gland. Your classmate
describes its function.
Exocrine glands
They secrete substances into a body
cavity or outside the body through
ducts.
– Endothelia. This tissue lines the interior surfaces of the body,
such as the blood vessels and the heart. It consists of a single layer
of cells.
• Glandular epithelia. This tissue makes up the glands. It produces
and secretes substances. There are three types of glands:
Endocrine glands
They secrete hormones directly into
the bloodstream without ducts.
Glandular epithelial cells
Mixed glands
They produce other substances and
secrete hormones into the blood.
Pancreas
Duct
Glandular epithelial cells
Sweat glands secrete sweat. The liver
secretes bile through a duct into the
gall bladder.
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Blood vessel
The thyroid gland secretes hormones
such as thyroxine, which controls the
body's metabolic rate and growth.
Hormoneproducing cells
Pancreatic
juice-producing
cells
The pancreas secretes hormones like
insulin into the bloodstream and digestive
enzymes into the small intestine.
The organization of the human body 1
Connective tissue
This tissue connects other tissues. It has three components: cells,
fibres (that may or may not be made of collagen) and an intercellular
substance or matrix. There are several types:
Osseous or bone tissue. The cells
responsible for bone formation,
osteoblasts, produce a strong, solid
matrix. Star-shaped bone cells found in
mature bone are called osteocytes.
Osteocyte
Dense connective tissue. It
is found between tissues and
organs holding them together.
Tendons and ligaments are
typical examples.
Adipose tissue. It is made up of
adipocytes or fat cells. They store
lipids and protect some organs.
Cartilage tissue. Its cells,
chondrocytes, contain elastic fibres
and produce a solid, flexible matrix
like the cartilage found at joints.
Adipocyte
Chondrocyte
Blood tissue. This special
tissue is made up of red
and white blood cells. Its
matrix, plasma, is liquid
with no fibres. Blood tissue
transports substances.
Muscle tissue
This contractile tissue has elongated cells called myocytes or muscle
fibres. It contains protein filaments of actin and myosin which
contract and relax muscles. There are three types of muscle tissue:
• Smooth muscle tissue. The myocytes have a single nucleus.
Contraction is involuntary. This type of muscle tissue is found in the
walls of internal organs.
• Skeletal muscle tissue. Skeletal myocytes have many nuclei.
Skeletal muscles are striated with dark and light bands. Contraction
is voluntary. Skeletal muscle tissue forms skeletal muscles.
Striated muscle tissue
• Cardiac muscle tissue. Cardiac myocytes are joined in a network.
They have a single nucleus and the cytoplasm looks striated.
Contraction is involuntary. This tissue forms most of the heart wall.
ACTIVITIES
Nervous tissue
Nervous tissue cells transmit and receive information throughout the
body. There are two types of cells:
• Neurons. They are star-shaped with branching projections. They
transmit nerve impulses.
• Glial cells. They nourish and support the neurons. They do not
transmit nerve impulses.
5 Make a table of the
different types of
connective tissue. Use
these headings: Tissue
type, Cell name, Function.
6 What special
characteristics do cells that
form muscle tissue have?
And nerve cells?
15
LEARNING OBJECTIVES
8
Organs and organ systems
• Identify the organ systems of
the human body.
• Relate organ systems to the life
functions they are involved in.
The human body is made up of many organs organized by function
into organ systems. These systems work together to enable the body
to function. The science that studies how living systems function is
called physiology.
• Organ. A group of tissues that work together to perform a specific
function or action. The heart, skin and muscles are examples of
organs.
WORK WITH THE IMAGE
1 Work with a classmate:
describe the difference
between an organ and an
organ system.
2 Play a matching game in
pairs. One person says an
organ system; the other
person names the organs in
that system. How many
organs can you match to
systems in one minute?
• Organ system. A group of organs that work together to perform
one or more functions. For example, the circulatory system consists
of various organs (the heart, veins and arteries) that work together
to transport nutrients throughout the body. The skeletal system is
made up of bones that perform different functions. For example, the
humerus and vertebrae are involved in movement; the ribs and
sternum protect organs.
Organ systems can be grouped by function: nutrition, interaction and
reproduction.
Organ systems involved in nutrition
These organ systems obtain nutrients, transport them throughout the
body and eliminate harmful substances produced in the body.
Digestive system. It consists of the digestive tube
and accessory glands (salivary glands, the liver and
pancreas). It obtains nutrients from food.
Circulatory system. It consists of the heart, blood and
blood vessels. It distributes blood, which delivers
nutrients to all the cells and collects harmful
substances.
16
Respiratory system. It consists of the respiratory
tract and the lungs, where gas exchange with the blood
takes place. This exchange provides oxygen to the body
and eliminates carbon dioxide produced by the cells.
Excretory system. It consists of the kidneys, the
urinary tract (ureters, the bladder and urethra) and
other organs, such as the sweat glands. Excretion is the
process of eliminating waste substances. These waste
substances are produced by the chemical reactions
that occur in cellular metabolism.
The organization of the human body 1
Organ systems involved in interaction
These organ systems enable the body to communicate and interact with
the environment.
Nervous system. The
main organs are the brain,
spinal cord and nerves. The
nervous system receives
information from the
internal and external
environment. It then sends
nerve impulses (messages)
to organs in response to this
information.
Endocrine system. The
organs in this system are the
endocrine glands, which are
made of glandular epithelial
tissue. These glands produce
chemical substances called
hormones, which are
excreted into the
bloodstream. Hormones act
on specific cells and organs.
Musculoskeletal system. It consists of
muscles and bones that work together to
produce locomotion.
Skeletal system. It is the passive part of
the musculoskeletal system. It consists of
bones of different types and shapes. The
mineral matrix of bone tissue provides
strength and stiffness. The skeletal system is
involved in locomotion. It also protects
organs and structures.
Muscular system. It is the active part of
the musculoskeletal system. It consists of
skeletal muscle made of skeletal muscle
tissue. It enables locomotion and
movements and helps to maintain posture.
Organ systems involved in reproduction
Reproductive systems. Male and female systems, each consisting of
internal and external organs. This system produces reproductive cells or
gametes.
The male
reproductive system
produces sperm and
male sex hormones.
The female reproductive
system produces ovules
(eggs) and female sex
hormones. After fertilization,
it hosts the developing
foetus until birth.
ACTIVITIES
3 Summarize the information on these three organ
systems and their organs in a mind map.
4 What organs are involved in two different life
functions? Name the organ systems they are
related to.
17
ACTIVITY ROUND-UP
1 Copy and complete the diagram of the levels of
6 A white blood cell ingests a bacterium by phagocytosis
organization in human beings.
and digests it intracellularly. What organelles are
directly involved in this process: the mitochondria, the
Golgi body, lysosomes or the vesicles? Explain why.
7 Look at the pictures and answer the questions.
A
B
Cell
a) What organelles or cellular structures are visible in
each picture? What are their functions in the cell?
b) Are these pictures of a prokaryotic or eukaryotic cell?
Explain how you know.
8 Why do cells need a cell membrane?
9 What is the relationship between DNA, chromatin and
2 Make a table to classify inorganic biomolecules and
describe their components.
chromosomes?
10 How are endoplasmic reticulum, the Golgi body and
3 What type of metabolic reaction produces energy? What
type requires energy? Draw diagrams to explain what
occurs in each case.
4 Copy the drawing in your notebook. Add a title and
label parts A–E. Which living things have this type of
cell?
vesicles related?
11 Identify each type of tissue, the name of the cells it is
made of and the function of the tissue. Explain how
you recognized the tissues.
A
B
A
B
COOPERATIVE PROJECT
A poster on cellular structures
C
E
D
5 Choose four organelles present in eukaryotic cells.
Make a fact sheet to compare them. Use these
headings:
• Name of the organelle.
• Main characteristics.
• Function or functions.
• Drawing of the organelle.
18
Posters are a form of visual communication. Good
posters combine text and graphic elements in an
attractive design. Texts, photos and illustrations
should be large, clear and concise.
• Form groups to design the poster for lab photos
that will be used in an exposition.
• Organize the work so each group member has a
different task.
• Select the photos; write the texts using fact sheets.
Use Activity 15 as a model.
• Assemble the poster using the contributions from
each group member.
KNOW HOW TO
The organization of the human body Scientific competence
1
Identify cells and cell structures in micrographs
The images below were taken using optical and
electron microscopes.
A
B
C
They correspond to different types of tissue, cell
structures and organelles.
MICROGRAPHS
• Mitochondria.
D
E
F
• Ciliated epithelium.
• Pores in the
nuclear envelope.
• Ovule (egg).
• Blood tissue.
• Centrosome.
• Cardiac muscle.
• Neuron.
• Adipose tissue.
• Buccal epithelial
cells.
• Cartilage tissue.
• Rough ER.
• Golgi body.
• Cell nucleus.
• Flagellum.
• Glandular tissue.
PRACTICAL MANUAL OF MICROSCOPY
Optical microscope (OM)
• Maximum magnification: 1 000 X.
• Samples are stained to colour them.
• Living material can be viewed.
Scanning electron microscope (SEM)
• Maximum magnification: 500 000 X.
Sperm (OM). Cell movement
can be observed.
Sperm (SEM). The surface is
visible in 3D.
• Black and white images can be stained.
• Surface images are in 3D.
• Living material cannot be viewed.
Transmission electron microscope (TEM)
• Maximum magnification: about 1 000 000 X.
• Black and white images can be stained.
• Internal structures are in 2D.
• Living material cannot be viewed.
ACTIVITIES
12 Design a fact sheet for photos A–F. Identify the cell
and include information about: cell structure, the
organelle or tissue, the type of microscope used.
13 Make simple drawings of photos C–F. Label the
parts of each cell and explain:
• The type of cell it is found in. • Its main function in the cell.
Sperm (TEM). The orderly arrangement of the mitochondria
can be observed in the tail. The nucleus is visible in the head.
14 If you had to use assisted reproduction techniques,
would you donate spare embryos for research?
15 Which microscope would you use to view:
• The wing of a fly. • The inside of a mitochondrion. • The surface of a nuclear envelope. • The shape of a chromosome. • The cilia of a paramecium.
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