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Unit 1 – Cells and Systems
Chapter 1 – The cell is the basic unit of life.
1.1 Observing Living Things
-living things can survive in almost any kind of environment
-have features that help them survive
-ex: hummingbirds can beat wings up to eighty times per second,
allowing them to hover and change direction rapidly
-all living things have needs that must be met if they are to survive
*Characteristics of Living Things*
-five characteristics of living things:
-living things respond to their environment
-living things need energy
-living things grow
-living things reproduce
-living things must get rid of wastes
*Examining Very Small Living Things*
-electron micrographs: images made by electron microscopes
-microscope is used by scientists to observe very small unicellular and
multicellular living things
-early microscopes were built in late 1600’s
-Anton van Leeuwenhoek was one of first people to build a microscope
-magnify up to 250x; used it to observe microscopic things
*Compound Light Microscope*
-sets of lenses that magnify an image
-magnification power: the number of times larger an image appears under a
particular lens
-Low power – 4x objective
-Medium power – 10x objective
-High power – 40x objective
-multiply objective by eyepiece for total magnification
-ex: High power – 40x10 = 400x
*Resolving Power*
-resolving power: ability to distinguish between two dots or objects that are
very close together
-human eye has certain resolving power
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1.2 Cells
-unicellular: one-celled; multicellular: more than one cell
-organelles: internal structures in which cell functions are carried out
-cellular respiration: the process in which glucose and oxygen produce energy
for the cell
-glucose +oxygen (produce) carbon dioxide + water + energy (ATP)
-metabolism: total of all chemical reactions that take place in our cells
-cells must have a balance of life processes to survive
-intake and storage of nutrients
-growth
-response to stimuli
-exchange of gases
-waste removal
-reproduction
*Cell Theory*
-all living things are made of at least one cell
-cells are the functional unit of life
-all cells come from pre-existing/other cells
*Organelle Functions*
-organelles: internal structures; special cell functions are carried out
>Cell (plasma) Membrane – thin outer covering that regulates materials
going in and out of the cell
>Cytoplasm – jelly-like substance made of water that contains the
organelles
>Nucleus – structure that directs all cellular activities, contains DNA
-DNA: deoxyribonucleic acid; carries heredity material that is
passed on from generation to generation
>Vacuole – in plants mostly, contains water – storage compartments;
smaller in animal cells and usually called vesicles
>Centrioles – protein fibres that aid cell division in animal cells by
helping to move chromosomes
>Mitochondrion – converts the chemical energy in glucose into ATP
energy that the cell can use; cellular respiration
>Ribosome – where proteins are assembled; without membrane
>Endoplasmic Reticulum – networks of membranes within the cytoplasm
that transports material through the cell; some ribosome attach to it
>Golgi Body – sorts proteins and packs them into vesicles (membranewrapped structures)
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>Lysosome – contains digestive chemicals that break down food
particles, cell wastes, and worn-out cell parts
>Cell Wall (only in plants) – structure that surrounds the cell
membrane; maintains shape and protects plant
>Chloroplast (only in plants) – carries out photosynthesis
-photosynthesis: chemical reaction that takes place when
carbon dioxide and water react in the presence of sunlight to
produce glucose and oxygen
*Prokaryotic and Eukaryotic Cells*
-cells are classified into two groups:
-Prokaryotic cells: have no nuclear
membrane or organelles
-Eukaryotic cells: have organelles that
are surrounded by membranes, usually
larger than prokaryotic cells (animal
and plant cells)
*Bacteria*
-bacteria: any of various groups of single-celled micro-organisms, some of
which can cause disease
-can vary from 1 mm~20 nm in length
-average range is 1 µm~20 nm in length (mm = millimeter; µm =
micrometer; nm = nanometer)
*1000 mm = 1 m
1 000 000 µm = 1 m
1 000 000 000 nm = 1 m
-bacteria have beneficial effects, such as digestive enzymes that help
digest food in our intestines; used to make food such as cheese/yogurt
-can also have bad effects on cells by producing toxins, reproducing causing
more damage; diseases such as tuberculosis and strip throat
-three common shapes:
Baccilli (rods)
Spirilla (spiral)
Cocci (spherical)
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*Viruses*
-virus: tiny non-living particles capable of reproducing only when they are
inside a host cell; they have no nucleus or organelles and are usually diseasecausing
-ex: HIV, chicken pox, cold sores, flu
-carries only the information, in form of DNA, necessary to reproduce itself
1.3 Diffusion, Osmosis, and the Cell Membrane
-diffusion: natural movement of particles form areas of higher concentration
to areas of lower concentration; ex: smell of fresh baked bread ‘spreading’
throughout the room
-concentration: the amount of a substance in a given space
-equilibrium: when concentration on both sides of membrane is same
-cell membranes act as barriers to diffusion
-selectively permeable: allows some things through
-osmosis: passive transport or diffusion of water across a selectively
permeable membrane
-if water concentration inside the cell is higher than it is on the
outside, water will flow out of the cell; vice versa
*Osmosis and the Cell*
-cells contain water and need this water to survive
-osmosis = how the cell gains and loses its needed water
-equal movement of water in and out of cells:
-cell retains its normal shape
-more water moving into cells than is moving
out:
-cell swells; red blood cells may
continue to swell and eventually may
burst; plant cell swells beyond its
normal size
-more water moving out of cells than is moving
in:
-cell shrinks; red blood cells shrivel up as
they lose water; plant cell membrane
shrinks away from the cell wall –- carrot
is limp, lack of water
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Chapter 2 – Human body systems work independently and together.
2.1 Body Systems
-all systems have following characteristics:
-is made of individual parts that work together as a whole
-is usually connected to one or more systems
-if one part of a system is missing or damaged, the system will not
function well or may not function at all
*Eleven Systems of the Human Body*
>Circulatory System – transports blood, nutrients, gases, and wastes
>Digestive System – takes in food; breaks down food; absorbs nutrients;
eliminates solid waste
>Respiratory System – controls breathing; exchanges gases in lungs and
tissues
>Excretory System – removes liquid and gas wastes from the body
>Immune System – defends body against infections
>Endocrine System – manufactures and releases hormones
>Reproductive System – includes reproductive organs for producing offspring
>Integumentary System – includes skin, hair, and nails; creates a waterproof
barrier around the body
>Skeletal System – supports, protects, and works with muscles to move parts
of the body
>Muscular System – has muscles that work with the bones to move parts of
the body
>Nervous System – detects changes in the environment and signals these
changes to the body, which then carries out a response
*Organ Systems*
-organ system: system that includes one or more organs that work together
to perform specific functions in the body
-tissues: a group of cells that have the same structure and function
-organ: a group of tissues (such as heart tissues) working together to
perform a task (such as pumping blood)
-within each organ system are tissues and cells
-cells of the same structure and function are grouped into tissues
-groups of tissues form organs
-heart cell  cardiac tissue  organ
(heart)  organ system (circulatory
system)  organism
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*Tissues*
-word ‘tissue’ comes from Latin word meaning to weave
-cells that make up tissues are often ‘woven’, or held together by fibres or
sticky materials that form between tissue cells
-four types of body tissue:
-muscle tissue: assists in body movement (skeletal muscle tissue);
helps some organs carry out specific functions (heart pumping blood)
-nerve tissue: transfers signals in the body and its organs to tell body
how to respond to changes in its internal and external environment
(transfers signals to and from brain)
-connective tissue: holds together/supports other tissues; connects,
protects, insulates organs
-epithelial tissue: covers surface of organs and body; lines inside of
body parts
2.2 The Digestive and Excretory Systems
-to grow, your body needs raw material or nutrients
-nutrients: substances the body requires for energy, growth,
development, repair, or maintenance
-comes from your diet
-four food groups:
-grain products
-vegetables and fruit
-milk products
-meat and alternatives
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*Types of Nutrients*
-five different types of nutrients you can obtain from food
-balanced diet will have correct amount
>carbohydrates: the body’s quickest source of energy
-two kinds:
>>simple carbohydrate: molecules of sugar, most common type
of sugar  glucose
>>complex carbohydrate: chain of simple carbohydrates joined
together
-body must break down the chain into simple sugars to
use the energy; ex: pasta, brown rice, whole grain cereals
-proteins: used to build muscles, skin, hair, nails; within cells, are used to
build various structures and are required for certain chemical reactions
-ex: fish, poultry, meat, nuts, soy, dairy products – rich in proteins
-fats: used to build cell membranes and that can be stored by the body for
future energy needs
-ex: shortening, butter, oil, cream, meant
>>unsaturated fats: come from fruits, vegetables, and fish
-liquid at room temperature
>>saturated fats: usually animal fats, such as butter or lard
-solid at room temperature
-diets rich in saturated fats can lead to an increase in heart
disease; plaque builds up in blood vessels, and flow of blood is
reduced
-plaque: fatty material that is deposited along the walls
of blood vessels
-leads to an increased risk of heart attack and
stroke
-minerals & vitamins: needed in small amounts to perform various body
functions
-vitamin D helps body absorb calcium; sunlight helps make vitamin D
--water: not a nutrient, but is essential for life
-transports nutrients and wastes
-necessary for many chemical reactions and for cooling the body
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*The Four Stages of Digestion*
-digestion: the process in which food is broken down, its nutrients are
absorbed and stored, and the wastes are eliminated
-digestive system: the system of organs and body structures that work
together during the process of digestions
①  ingesting – starting point of the digestion process; mouth
②  digesting – mouth: mechanical and chemical digestion begins
>-mechanical digestion: the chewing and breaking food
down into smaller pieces
>-bolus: each small piece of food
-saliva lubricates the food, and contains an enzyme called
amylase
>-chemical digestion: occurs when amylase begins to
break down complex carbohydrates
-esophagus: as food passes through the pharynx, the epiglottis covers
the airway tube
-food moves on to the esophagus
>-esophagus: tube that connects the pharynx and the stomach
☇ long and muscular
>-bolus is pushed through the esophagus in a process called
peristalsis
-stomach: like a stretchable muscular bag
-inside stomach is gastric juice; very acidic
>-gastric juice: a mixture of hydrochloric acid, mucus, and
enzymes; secreted by the stomach lining and aids in digestion
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-walls are lined with mucus that protects the tissue
>- pepsin: enzyme which breaks down protein, and needs an
acidic environment
>-bolus breaks down into liquid called chyme
-small intestine: once chime leaves stomach, it empties into the small
intestine
-first metre is called the duodenum
☇ digestion is complete after food leaves
-within the first 30 cm are ducts that connect to other organs
>-pancreas: produces enzymes
-liver produces bile; ☇ bile: break globs of fat into smaller
droplets
③  absorbing – nutrients are absorbed by the remaining 5 m of the small
intestine
-to help increase the rate of absorption of nutrients,
small intestine is covered in villi (sing. villus)
☇ villi: folds in the wall of the small intestine; increases
the surface area from 0.5 m^2 to 250 m^2
-food takes approx. five to six hours to move through
small intestine
-large intestine: 5 cm wide, 1.5 m long
☇ takes undigested material from the water and some
nutrients
-90% of water is absorbed by the time the undigested
material leaves the large intestine; -12~24 hours
-beneficial bacteria helps breakdown and absorption of
food
④  elimination – any undigested materials left are called feces
☇ feces: solid waste products -> stored in the rectum
until they are eliminated through the anus
-ingestion to elimination takes approximately 20~30hours
*Excretion*
-the excretory system removes liquid and gas wastes from your body
-excretion removes liquid wastes through the urinary tract
-main organs: two kidneys, two ureters, the bladder, and the urethra
-kidneys filter blood and removes wastes
-urine passes into the bladder, and is flushed out through the urethra
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*Nutritional Disorders/Eating Disorders*
-obesity: excess in body fat
-anorexia nervosa: occurs when a person severely restricts what he/she eats
- resulting medical problems could include damage to internal organs
and weakening of bones
-bulimia nervosa: occurs when a person eats large amounts of food and then
vomits or takes laxatives to get rid of the food before it can be completely
digested
-health problems include stomach and esophagus irritation and tooth
decay from stomach acid in vomit
2.3 The Circulatory and Respiratory Systems
-circulatory system consists of the heart, arteries, capillaries, and veins
-your heart is a pump; pushes approximately 4 L of blood through body every
minute
-main purpose of respiratory system is to exchange gases
-main organ of respiratory system are the lungs
*Taking a Closer Look at the Heart*
-heart: muscular organ that pumps blood throughout your body
-four chambers:
-atria (left/right) – moves the blood from the body into the heat;
pumps blood into ventricles
-ventricles (left/right) – pumps the blood out of the heart
♦ Left atrium
◘ blood arrives from your lungs
♦ Right atrium
◘ blood arrives from your body
♦ Left ventricle
◘ pumps blood to your body
♦ Right ventricle
◘ pumps blood to your lungs
-between the chambers are one=way valves
-valves allow blood to flow in only one direction
-‘Lub dub’ – opening and closing of the valves
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*The Circulatory System*
-made up of blood vessels
-if all blood vessels lined up, approximately 100 000 km
-types of blood vessels
☇ arteries: blood vessels that carry blood away from the heart
-most carry oxygenated blood
-thick-walled and elastic to handle blood flow
-largest artery  aorta
-arteries branch into arterioles, and finally capillaries
☇ capillaries: networks of tiny blood vessels that connect arteries to
venules; where gases and nutrients are exchanged with the cells
-venules: smallest veins in the body, join veins to capillaries
☇ veins: blood vessels that carry deoxygenated blood back to the heart;
have valves that prevent backflow of blood
-blood returns to heart through veins, superior vena cava, and inferior
vena cava
-superior vena cava: large vein that carries deoxygenated blood
from the head and arms back to the right atrium of the heart
-inferior vena cava: large vein that carries deoxygenated blood
from the lower body to the right atrium of the heart
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*The Components of Blood*
-blood: the fluid that transports substances to and from all parts of the
body; consists of plasma, red blood cells, and white blood cells
-transports oxygen, nutrients, and water to cells; carries carbon
dioxide and wastes away from you cell
-also carries cells that fight infection and heal wounds
-55% of 5 L of blood is plasma
-plasma: clear, yellowish fluid that contains numerous
water, proteins and minerals, dissolved salts
-45% of 5 L of blood are red blood cells, white blood cells, and
platelets
-red blood cells: carry oxygen from lungs to body and carbon
dioxide from body to lungs; formed in the bone marrow, liver,
and spleen
>-within each RBC are protein molecules of haemoglobin;
carries oxygen in the capillaries
-white blood cells: fight infections; much larger than RBC’s
-platelets: help clot blood by thickening blood; forming scabs
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*The Respiratory System*
-when you breathe, you inhale oxygen and exhale carbon dioxide
-lungs deliver the oxygen, and excrete carbon dioxide
-breathing brings the oxygen in, air is filtered by cilia and mucus
-cilia: tiny hairs
-air travels down the pharynx and larynx (voice box), and then the trachea
-pharynx: tube at the meeting point of the airway passage and the
esophagus
-larynx: tube-like structure that contains vocal chords; air passes
through larynx to produce sounds of voice
-trachea: airway passage that leads from larynx to lungs
-at the base of the trachea are the bronchi, which branch into smaller tubes
called bronchioles
-bronchi: two tubes that branch out from trachea into the right and
left lungs
-bronchioles: in the lungs, small air tubes branching out from bronchi
-finally, air reaches tiny sacs – alveoli
-alveoli: in the lungs, tiny, thin-walled air sacs at the ends of
bronchioles, where gas exchange takes place
*Gas Exchange in the Alveoli*
-each alveolus is surrounded by capillaries
-oxygen diffuses out of alveolus, into blood and binds with red blood cells,
and carbon dioxide diffuses into the alveolus
-oxygenated blood returns to heart to be pumped to rest of body
*Smoking*
-causes many respiratory diseases, such as lung
cancer and emphysema
-emphysema causes alveoli walls to lose
elasticity, makes breathing increasingly difficult
as disease progresses
-over 4000 chemicals in a cigarette
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Chapter 3 – The immune system protects the human body.
3.1 The Immune System
-infectious disease – can be spread by contact with infected people, animals,
water, or food
-pathogens: disease-causing ‘invaders’/organism or substance
-four ways to transmit infectious diseases
>-direct contact – shaking hands, sharing drinks or bodily fluids with
an infected person
>-indirect contact – being near an infected person who sneezes
without covering his or her mouth
-some pathogens can travel up to 5 m and infect
people within that range
>-water and food – eating foods infected with certain bacteria
(food poisoning)
-ex: Salmonella
-drinking water infected with E. coli bacteria can
result in serious illness
>-animal bites – being bitten by an animal carrying rabies
*First Line of Defence*
-skin and linings of all internal body systems
-sweat and oil are acidic
-gastric juice is very acidic
-can destroy pathogens
-mucus and cilia prevent pathogens from
entering your respiratory system
*Second Line of Defence*
-innate immune response
-response you are born with
-quick and general
-usually fight bacteria and some
viruses
-first action is a flow of fluid, cells,
and dissolved substances to the
infection site
-fever, inflammation, and redness occur
☇ inflammation: swelling and redness
-phagocytes will increase in number
☇ phagocytes: a type of white blood cell that fights infection by
swallowing up/engulfing pathogens
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-acquired immune response
-highly specific attack on pathogens or antigens
☇antigens: any substance the body cannot recognize, it is a non-living
particle or substance
-your body uses white blood cells called B cells and T cells to respond
-B cell: type of white blood cell that recognizes antigens
present in body and produces specific antibodies to fight them
-T cell: specialized white blood cells that fight disease either
by activating B cells (helper T cells)/by attacking antigens
directly (killer T cells)
-process can take up to a week
(first process) -B cells recognize antigens and produce antibodies to fight them
☇antigens: specific particles created by the immune system to
destroy specific disease-causing invaders
-antibodies attach & destroy antigens and pathogens carrying antigens
-T cells: helper T cells recognizes an antigen or pathogen and
activates B cells
(second process)
-killer T cells: work independently, destroy antigens
pathogens
-all acquired immune responses help give you active immunity
-your body remembers which antibodies should be used to
attack a pathogen that it has seen before
-memory B cells store the new antibodies
>Recognition: white blood cell surrounds pathogen and signals T cells; more
T cells produced; helper T cells signal B cells
>Mobilization: B cells produce antibodies
>Disposal: antibodies destroy pathogens
>Immunity: some antibodies remain for future use
3.2 Factors Affecting the Immune System
*Montagu’s Observations*
-Mary Montagu traveled to Turkey in 1717, discovered a vaccine for smallpox
-women performing procedure, seemed to protect children getting smallpox
-women made small scratch on child’s arm, then put drop of pus from a
patient who had mild case of smallpox on scratch
-soon pus-filled blisters broke out on the child’s body; healed easily
-children treated this way quickly recovered from this mild version of
smallpox without ever developing serious form of disease
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*Jenner’s Famous Experiment*
-Jenner gave eight-year-old boy cowpox by placing him near infected cows
-after boy recovered, Jenner infected him with smallpox
-did not develop an of symptoms of smallpox
*Vaccines*
-vaccine: a special version of an antigen that gives you immunity against a
disease; weakened forms of a disease
-stimulates your immune system to create antibodies against the disease
-these antibodies are reactivated to fight the antigen if it enters body
-some vaccines require booster shots
-all grade nine students receive booster shots for tetanus, diphtheria, and
pertussis
*Disorders of the Immune System*
-allergy: an unusually high sensitivity to some substance
-allergen: something that causes an allergic reaction
-acts as an antigen, and your immune system kicks in
-symptoms of an allergy are caused by histamine
-histamine: a chemical released by the body in response to an injury or
allergen; can cause symptoms such as a runny nose and watery eyes
-anaphylactic shock: severe allergic reaction that can result in swelling,
breathing difficulty, and sometimes death
-adrenaline auto-injectors are one-time-use needles that inject
adrenaline into body to counter allergic reaction
-Acquired Immunodeficiency Syndrome (AIDS): an infection of the immune
system
-caused by Human Immunodeficiency Virus (HIV)
-HIV attacks immune system itself, and destroys it by affecting
helper T cells; immune system unable to activate killer T cells or B
cells
*Taking Care of Your Immune System*
-eat a well-balanced diet
-maintain person hygiene – brush teeth, shower/bathe, wash hands often
-keep home clean
-avoid tobacco and other non-prescription drugs
-get plenty of rest and exercise
-keep vaccinations up to date
-do not engage in activities that involve sharing body fluids with others
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