Download Review Notes Biology 20

Unit 1: Energy Flow and Cellular Matter
Cellular Chemistry:
 Metabolism: sum of all chemical reactions that occur within the cell.
 Catabolism: chemical reactions in which complex molecules are broken
down into smaller compounds.
 Anabolism: chemical reactions where simple molecules are combined
together to form more complex compounds.
Organic Chemistry:
 Chemistry of carbon ~ hydrocarbons (HC’s)
Carbohydrates: sugars (CHO) ending of OSE
 Role: Structure: cell wall in plant cells ~ cellulose. Function: energy.
 Monosaccharides: simple single sugars ~ C3 to C10
 Disaccharides: double sugars that are combinations of single sugars.
 Polysaccharides: many sugars. General formula (C6H10O5).
o Cellulose (dietary fibre) Starch ~ plant storage carbohydrate.
Glycogen: animal starch ~ animal storage liver and muscles.
Chemical Tests:
 Starch Test: drops of iodine solution; blue or black color indicates
presence of starch.
 Reducing (mono & diasaccharide) Sugar: drops of Benedict’s solution.
Lipids: (CHOP) ending of OL
 Role: Structural: phospholipids in cell membranes and fat deposits for
physical protection. Functional: fat deposits for heat insulation and long
term storage of energy.
 Triglycerides: union of glycerol and three fatty acids.
o Fats: animal lipids composed of glycerol and saturated fatty acids.
o Oils: plant lipids composed of glycerol and unsaturated fatty acids.
 Phospholipids: phosphate molecule is attached to the glycerol molecule
making the molecule polar. Major components to cell membranes in
animals and plants.
Chemical Test:
 Lipids Test:
1. Grease spot test on brown paper, translucent result indicates fat or
oil.
2. Add a trace of Sudan IV stain that is only soluble in lipids: color will
show.
Proteins: structural components of cells. (CHONS) ending of IN
 Roles: Structural: cell membrane and determine the shape of cells.
Functional: enzymes control all chemical reactions, hormones, and
energy.
 Very large macromolecules composed of Amino Acids.
Amino Acid ~~~ peptide bond ~~~~ Amino Acid
 Primary Structure: polypeptide chain O-O-O-O
 Secondary Structure: coil made of weak hydrogen bonds
 Tertiary Structure: unique 3-dimensional structure allows proteins to
become very specific and determines largely the properties of that protein.
o This process is called Denaturation ~ uncoiling the protein shape.
 Caused by environmental agents: Heavy metals ~ Pb and
Hg. Electricity ~ electrocution Heat ~ cooking eggs or fever
pH
 Sometimes if the agent is removed the protein can recapture
its shape, if not the permanent change is referred to
Coagulation.
Chemical Test:
 Protein Test: drops of Biuret Reagent (test for the peptide bond), a violet
color indicates the presence of protein.
Chemical Processes:
 Dehydration Synthesis: combination of simple molecules to form larger,
macromolecules which yields a water molecule.
 Hydrolysis: breaking down of a macromolecule to form simpler,
micromolecules through the addition of water.
Enzymes: “lock and key” hypothesis. Suffix ~ ase
Protein
Reactant :
2 Glucose
Must stretch to
+
Active
Site
Enzyme
(maltase)
+
H2O
break the bonds
Complementary
Shape
Substrate
(Maltose)
Enzyme/Substrate
Complex
Enzyme
Product
Induced fit hypothesis.
Substrate and enzyme must stretch and strain to fit. The strain breaks the bonds.
Characteristics of Enzymes:
 Proteins
 Needed in small quantities (reuseable)
 Substrate specific
 Action is reversible
 Organic catalysts
Great energy
Of activation
Less energy of activation
No Enzyme


Enzyme
Allow chemical reactions to proceed under “milder” conditions in terms of
temperature and pH.
Have optimum pH and temperature where they are most effective or work
the best.
Temperature
Reaction
Rate
pH
Opt.
Reaction
Rate
Temp.

pH
Rate is regulated by the relative amounts of enzyme and substrate.
High
(150)
Reaction
Rate
Low
Enzyme (100)
Concentration of Substrate
Co-Enzyme:
 Chemical molecules, such as a vitamin, which are needed to alter the
active site of enzymes to correctly fit it with the substrate.
Competitive Inhibition:
 Interference, caused by a non-substrate, with the active site of an enzyme
or a specific site on a substrate.
 This chemical interference prevents the normal chemical reaction that
involves that enzyme.
Non-Competitive Inhibition:
 A process where a substance that doesn’t resemble the substrate at all
attaches to the enzyme (not on its active site) which rearranges the
enzyme rendering it useless.
Negative Feedback ~ Homeostasis:
 The ability of the body to keep the normal internal body environment in a
stable state even as the external environment is changing.
 Stops a process
Positive Feedback ~ Precursor Activity:
 Activation of the last enzyme in a pathway due to a build up of the initial
substrate.
 Starts a process
Biology 20: Unit 2 Cellular Respiration and Photosynthesis
Cell Organelles:
 Cell membrane: controls what comes in and out of the cell.
 Cytoplasm: solution within the cell.
 Endoplasmic reticulum (ER): contain ribosomes which are responsible
for protein synthesis.
 Golgi Apparatus: prepare materials for secretion (proteins or enzymes).
 Lysosomes: Digestive enzymes
 Mitochondria: produces most of the cell’s energy, has its own DNA.
 Plastids: plants only, sites of photosynthesis, has its own DNA.
 Vacuoles: storage deposits
 Cilia and Flagella: movement of the cell.
 Microfilaments and Microtubules: movement of materials within the cell
and movement of the cell itself.
 Cell Wall: plants only, supports the cell.
 Nucleus: determines the shape, metabolism, and heredity of the cell
(DNA).
Movement through the Cell Membrane:
Passive Transport:
 Diffusion: movement of materials from an area of high concentration to
an area of low concentration.
 Facilitated diffusion: macromolecules that are recognized by proteins on
the membrane guide the molecules into the cell using passive transport.

Osmosis: movement of water across a semi-permeable membrane from
an area of low solute concentration to high solute concentration.
o Isotonic – solution on both sides have the same concentration of
water.
 Hypotonic solution: solution with less solute concentration and
more water.
 Hypertonic: solution with more solute and less water
Active Transport: similar to facilitated diffusion but the movement of the
molecules requires the cell to use energy.
o Endocytosis: large particle is engulfed by the cell
 Pinocytosis: small particles engulfed by the cell
 Phagocytosis: large particles engulfed by the cell.
o Exocytosis: vacuole moves toward the cell membrane and dumps
the contents out.
o Ion Pump: small ions move against the gradient
ATP:
 Adenosine Triphosphate (ATP) is the storage form of energy for cellular
activity.
 High energy bond between the second and third phosphate group. Once
broken the energy released is transformed and used within the cell.
Anaerobic Metabolism: ~ absence of oxygen
Glucose
Glucose
2 lactic acid
Alcohol + CO2
+
+
6 ATP ~ animals
6 ATP ~ plants = fermentation
Aerobic Metabolism: ~ presence of oxygen
Glucose + 6 O2
(C6H12O6)
6 CO2 + 6 H2O + 36 ATP * more energy and excrete wastes.
Phosphorylation: the process of adding a phosphate to a molecule.
FOOD + P
FOOD – P
Phosphorylation
FOOD ~ P
Food Fragments
internal
(into the bond)
arrangement
(lactic acid)
ADP
ATP
Oxidation and Reduction:
 Oxidation: release energy when a compound loses electrons.
 Reduction: absorb energy when a compound gains electrons.

Hydrogen or Electron Transport:
o Hydrogen electrons in hydrogen gas or in organic molecule have a
great deal of energy.
o Hydrogen electrons in water have low energy.
H2 ~ hydrogen is separated
2H+
2eNAD
P + ADP
ATP
P + ADP
FAD
ATP
½ O2
3 ATP
ADP + P = ATP
Cytochrome
System
H2O
Cellular Respiration:
Glycolysis: Outside of the mitochrondria
ATP  ADP
Glucose
6C no P
add P
Glucose – Phosphate
6C1P
Fructose - Phosphate
6C1P
add p
ATP  ADP
Fructose - Diphoshphate
6C2P
2P + 2ADP  2ATP
2 Phosphoglyceric Acid
2 diphosphoglyceric acid
2 Glyceraldehyde – 2 P
(PGA)
(PGA)
add 2 P
(PGAL)
2P
4P
2ATP  2 ADP 3 C 2 P
2H2
2NAD
2 phosphopyruvic acid
2P
6 ATP
2 pyruvic acid (0 P 3 C)
Used 4 ATP
Gained 10 ATP
Net gain of 6 ATP
2NADH2
2ADP  2 ATP
Fate of Pyruvic Acid:
 Without Oxygen: Anaerobic
Staircase is incomplete 0 ATP
Lactic Acid animals
Ethanol plants ~ fermentation
Amount of ATP = 6 ATP due to glycolysis

With Oxygen: Aerobic
Staircase is complete 36 ATP
Citric Acid/Krebs Cycle: within mitochondria
Uses oxygen and produces carbon dioxide and water
The cycle is repeated 2 times.
Total ATP produced = 6 + (2 x 12) + 6 (from glycolysis) = 36
Water as a waste
Photosynthesis:
 The process whereby plants store solar energy into organic compounds.
6 CO2 + 12 H2O + solar energy
carbon water
sunlight
dioxide

C6H12O6 + 6 O2 + 6 H2O
glucose
oxygen water
Takes place in the chloroplasts of plant cells.
o Contains cellulose and cholorphyll which is the pigment that traps
sunlight.
o Photosynthesis takes place within specialized membranes called
thylakiod membranes.
o These membranes are stacked one upon another to form stacks
known as grana
o The fluid surrounding the grana is called stroma.
Chemiosmosis:
o Different pigments absorb different wavelengths of light that provide
the right amount of energy to the electrons within them.
 Ex: chlorophyll a, chlorophyll b, carotenoid
 See colours not absorbed by the object (Chloroplasts absorb
red and blue)
o The trapped energy excites the electrons and boosts them to a
higher energy level.
Photosystems:
 Energy capturing phase ~ light dependent
 The thylakoid membrane appears to have two systems that operate at the
same time.
High Energy
Electron
Acceptor
Electron
Acceptor
Electron transport system
3 ATP
Electron transport system
3 ATP
Photosystem I
Pigment
Photosystem II
Pigment
Low Energy
2e-
H2O
H+
H+
O (lost)
Photolysis: splitting of water by light energy
NADP
Co-enzyme
accepts H+ from
photolysis
NADPH
Calvin-Benson Cycle:
 Carbon fixing phase ~ light independent
 Occurs in the stroma
Light
12 H2O
Thylakiod Membrane
(Photosystems)
ADP, NADP+
6 O2
ATP, NADPH
Light Independent Reactions
6 CO2
6 H2O
3 cycles
Glucose
Surcose
Lipids Proteins
Unit 3: Energy and Matter Flow in the Human Body
Muscles:
 Tissue designed to convert chemical energy (ATP) into kinetic energy
(movement & heat).
 Supports body functions
 Responsible for locomotion (bones), heat production, peristalsis, breathing
etc.
Types of Muscle Tissue:
 Smooth Muscle: non-striated, one nucleus, contracts involuntarily, slow
and long contracts, don’t fatigue easily, and found along the wall of
internal organs.
 Cardiac Muscle: striated, tubular and branched, one nucleus, contracts
involuntarily, found in the walls of the heart.
 Skeletal Muscle: striated and tubular, contain many nuclei, contracts
voluntarily, attached to bones of the skeleton.
Functions of Skeletal Muscle:
 Opposes the force of gravity and enables standing
 Constant temperature by releasing of metabolic heat is distributed to the body
(shivering)
 Protects internal organs and stabilizes joints:
 Ligaments hold bones (cartilage in between) together at the
joints.
 Tendons attach muscle to bones
Cooperation of Skeletal Muscle:
 All muscle tissue contracts (shortens) and relaxes (lengthens).
 Muscles can only pull on a bone when they contract but there must be a force
that stretches the muscle after it has stopped contracting and relaxes
 Flexing causes the bone or limb to move away from its original position.
Extension is when the bone or limb moves towards its original position.
 Muscles are allows in pairs: antagonistic
o Bicep causes the arm to flex as the muscle shortens
o Triceps causes the arm to extend as the muscle shortens.
Hierarchy of Muscle Structure:
 Muscle (Tendon is heavy tissue that attaches to bone)
 Muscle-Fibre Bundle (connective tissue surrounds each muscle fibre
with nerve and blood vessel running between each bundle of fibres)
 Muscle Fibre (single muscle cell)
o Myoglobin (stores oxygen)
o Sarcoplasm (cytoplasm of the muscle fibre, containds myoglobin &
glycerine)
o Sarcolemma (membrane of the muscle fibre that regulates
movement of material)
o Sarcoplasmic Reticulum (stores calcium ions)
o Myofibrils (cylindrical sub-units that make up a muscle fibre)
 Myofilaments (protein structures responsible for muscle
contractions)
 Thick Filaments: composed of myosin(heads)

Thin Filaments: composed of actin
Mechanisms of Muscle Contractions:
1. Myosin head attaches to actin
2. Myosin head flexes, advancing the actin filament
3. Myosin head releases and unflexes, powered by ATP.
4. Myosin reattaches to actin farther along the fibre.
Sliding Filament Model of the Sarcomere
1. The heads of the two ends of myosin filament are oriented in opposite
directions. When the heads attach to the actin, they bend towards the
centre of the myosin.
2. As one end of the myosin filament draws the actin filament and its
attached Z line towards the centre, the other end of the myosin filament
does the same.
3. Both Z lines move towards the centre, and contraction occurs.
Role of Calcium Ions in Muscle Contraction:
1. Muscle is at rest: A long filament, composed of the protein molecule
tropomyosin, blocks the myosin binding sites of the actin molecule.
Without these sites exposure, muscle contraction will not occur.
Calcium ions bond with a molecule called troponin, which results in
exposing the myosin binding sites of actin so now muscle contraction can
occur.
Sequence in Muscle Contraction:
1. Nerve impulse travels to the muscle fibre bundle (stimulus)
2. Ca ions are released from the sarcoplasmic reticulum into the sarcoplasm.
3. Ca ions attach to the troponin (Ca receptor site) thereby causing the
tropomyosin to release from the actin.
4. Myosin heads can now attach, release, and reattach using ATP thereby
causing muscle contraction (z-lines move together).
Sequence in Muscle Relaxation:
1. Nerve impulse stops
2. Ca ions reabsorbed from sarcoplasm into the sarcoplasmic reticulum.
3. Absence of the Ca ions on the troponin allows tropomyosin to reattach to
the actin preventing the binding of myosin.
4. Myosin and actin just slide away from each other (z-lines move away).
Energy for Muscle Contractions:
 Stored Energy in a Resting Muscle:
1. Creatine Phosphate is built up and stored in a resting muscle.
2. Glucose and Glycogen is stored in muscle to be used during
cellular respiration.
 Release Energy (make ATP) and Contract the Muscle:
1. Breaks down creatine phosphate, adding the phosphate to ADP to
create ATP for immediate use.
2. Carries out anaerobic respiration, by which glucose is broken
down to lactic acid and ATP is formed.
 Lead to fermentation (another way of providing ATP without
oxygen which causes cramping and muscle fatigue)
 Oxygen Debt (replenish creatine phosphate and remove
lactate)
 More in shape a person is the more mitochondria he
or she has the less oxygen debt.
3. Carries out aerobic respiration, by which glucose, glycogen, fats
and amino acids are broken down in the presence of oxygen to
produce ATP.
Muscle Contractions or Twitches:
 Muscles require a stimulus (nerve) to contract, latent period, contraction
period (muscle shortens), and a relaxation period (when the muscle returns to
its former length).
 All or none response (one muscle fibre will contract).


When there is a short relaxation period, the muscle will fatigue due to a lack
of glycogen and excess lactic acid.
More stimulus is received, more 100% fibres bundles contract
Types of Muscle Twitches:
 Classified based on how fast the muscle fibres contract.
 Slow-Twitch: smaller, contract slow, produce energy aerobically, rich in
mitochondria, many blood vessels, and are resistant to fatigue
(endurance)
 Fast-Twitch: larger, contract fast, use a lot of ATP, rich in glycogen, low
in michondria, less blood vessels, produce energy anaerobically, and
fatigue faster (power)
 Intermediate –Twitch: fast twitch but have a high oxidative capacity. Can
increase the proportion of these fibers by training but also heredity.
Exercise:
 Limited by amount of glycogen stored and buildup of lactate.
 Adaptation to muscles that stores, utilizes, or spares glycogen and
removes lactate efficiently improves endurance.
 Hypertrophy: exercised induced increase in muscle mass
 Atrophy: reduction in muscle mass
o Loss of muscle mass as one ages
Disorders of Skeletal Muscles:
Technologies to treat muscle condition:
 Cold: reduces swelling after a tearing
 Heat: encourages blood flow to healing area (reduces pain and muscle
stiffness)
Unit 4 Digestion
Digestive Processes:
1. Ingestion: taking food into the body (eating).
2. Movement: propels food through the digestive system.
3. Secretion: release of digestive juices in response to a specific
stimulus.
4. Digestion: breakdown of food into molecular components
through the use of chemical and mechanical means.
5. Absorption: passage of the molecules into the body’s blood
stream and movement into the cells.
6. Egestion: removal of undigested food and wastes.
Mechanical Digestion verses Chemical Digestion:
Mechanical Digestion: molecules stay the same size and the
physical motions break big pieces into smaller pieces. Ex: chewing.
Chemical Digestion: molecules change and different molecules are
produced. Ex: enzyme action.
Factors that stimulate ingestion:
 Habit
 Hunger caused by low blood glucose levels.
 Brain stimulation
Organs of Digestion:
Organs are classified into two groups:
 Gastrointestinal (GI) Tract:
 Tube
 Oral cavity, pharynx, epiglottis, esophagus,
stomach, the small and large intestines, appendix,
and the rectum/anus.
 Accessory Structures:
 Teeth, tongue, salivary glands, liver, gallbladder,
and the pancreas.
 Digestive secretions.
Organs of Digestion:
Mouth: moistens food with secretions of saliva, grids food which
increase the surface area for chemical digestion, and directs the food
down the esophagus. Chewing or mastication food creates bolus.
Salivary Glands: secrets saliva into food, contains amylase
(enzyme) that begins the digestion of starch.
Epiglottis: a flap of skin in the pharynx region that closes off the
trachea when swallowing food.
Esophagus: a large muscular tube that carries food to the stomach.
It is made of smooth muscle that contracts in a peristaltic wave
motion, pushing the bolus of food along.
Peristalsis – squeezing, pushing down
Vomiting – reverse wave pushing up
Stomach:
1. Provides storage for 1 to 2 litres of material for 3 to 5 hours.
2. Mixes organic juices with a muscular wave-like motion.
3. Starts protein digestion.
4. Sets the rate of digestion between 4 to 24 hours.
Liver:
Chemistry lab of the body and is the largest gland
Produces bile (breaks down fats and neutralizes strong acids) which is stored in
the gall bladder.
Duel blood supply (poison smasher).
Pancreas:
 Endocrine gland that produces and secretes hormones into the
blood stream. (Insulin and Glucagon)
 Exocrine gland that releases chemicals into the small intestine.
Small Intestine:
Six meters long.
Majority of digestion and absorption occurs in this area.
Movement through active transport.
Three sections: duodenum (shortest), jejunum, and the ileum
(longest)
Absorption:
 Villius Structure:
Villi
Microvilli
Arterial
Venous Blood
To the liver (HPV)
Lymph Fluid



Uses active transport so the cells contain a large number of
mitochondria.
A capillary net supplies the mircovilli with oxygenated blood (arterial)
and removes carbon dioxide and organic molecules (amino acids,
glucose, fatty acids) through the venous vessels (deoxygenated)
toward the liver.
Glycerol and more fatty acids are removed via the lacteal vessel that
transports the materials to the lymphatic system.
Appendix:
Stores beneficial bacteria which assists in the digestion of organic material.
Large Intestine:
Absorbs water, minerals, and salts.
1. Decomposes left-over organic material with the help of resident bacteria
(e-coli) which produces vitamin B, K, and Folic acid.
Rectum & Anus:
Stores feces (undigested cellulose and matter) until it is appropriate to eliminate.
Digestion of Carbohydrates
Digestion of Lipids
Digestion of Proteins
Enzyme Summary:
Organ
Salivary Glands
Digestive
Secretion
Saliva
Stomach
Gastric Juice
Active Digestive Agent


Amylase



Pepsinogen (+HCL)
into Pepsin
Rennin
Lipase
Mucin
Liver
Bile
(gall bladder)

Bile Salts
Pancreas
Pancreatic Juice




Sodium Bicarbonate
Lipase
Amylase
Peptidase
Small Intestine
Intestinal Juice
(intestinal
glands)



Trypsin (active)
Chymotrypsin
(active)
Carbohydrase
o
o


o
Mucin
Erepsin
Maltase
Sucrase
Lactase
Action on Food

Breaks down starch
into maltose
 Protein to
peptide chains
 Clots milk
 lipids into 3 fatty
acids and 1
glycerol
 protective
mucus secretion
 Emulsifies fats
 Neutralizes
acids
 Neutralizes
acids
 Breaks down
fats to fatty acids
and glycerol
 Breaks down
starch to
maltose
 Continues the
protein
breakdown of
amino acids.
 Completes
digestion of
sugars to
glucose.
 protective
mucus secretion
 Continues the
protein
breakdown of
amino acids.
Absorption:
 Stomach: alcohol and drugs
 Small Intestine: organic compounds
 Large Intestine: water, minerals, salts, vitamins
How the liver handles excessive material:
 Glucose is stored in the liver and muscle in the form of
glycogen controlled by insulin. Insulin is produced by the
pancreas.
 Glycogen is released by the liver and muscles in the form of
glucose controlled by glucagon. Glucagon is produced by the
pancreas.
 Glycerol and fatty acids are converted into lipids and is stored
as fat.
 Amino acids broken down (deamination) into fatty acids that is
stored in the liver or in fatty tissue and urea which is excreted
via the kidney.
 Water and minerals are stored in the blood and excess goes
through kidneys.
 Vitamins that are water soluble goes through kidneys and
vitamins that are fat soluble are stored in fatty tissue.
Glands are stimulated by:
 Neural control: senses
 Hormonal control: hormones in the blood
 Mechanical control or Movement: peristalsis and other
movement
The hormonal control of digestion:
Cholecystokinin (CCK) and Secretin:
Trigger: food in the small intestine
Produced by: cells lining the duodenum
Released into: blood
Travels to: gall bladder and pancreas
Cause: release of bile to emulsify fat and the release of pancreatic
juice (protease, amylase, and lipase)
Effect: neutralizes acids and digests fats, starch, and proteins
Gastrin:
Trigger: presence of undigested food in the stomach
Produced by: cells lining the stomach
Released into: blood
Travels to: gastric glands
Cause: release of HCl, pepsinogen, and lipase
Effect: digests proteins and lipids
Technologies:
 Endoscope: tube-shaped camera that is inserted into the
abdominal cavity.
Unit 5: Excretion & Pulmonary Systems
Excretion:
Location of the Kidney: Renal
 Abdominal cavity towards the back
 Right kidney is slightly higher than the left kidney.
Diagram of the Urinary System:
Role of the Kidney:
 Remove “waste”
 Remove any chemical that is present in the blood in amounts greater than
the body needs. (water, salt, glucose, etc.)
Structure of the Kidney:
Nephron:
Deamination: Removal of amino group from an organic compound which forms
one molecule of urea and one fatty acid.
 Urea ~ two molecules of ammonia and one molecule of carbon
dioxide (less toxic)
 Uric Acid ~ waste from breakdown of nucleic acid
Processes of the Kidney:
1. Force or Glomerular Filtration:
 Movement of fluids (exception of proteins) from the glomerulus
(blood) into the Bowman’s capsule due to blood pressure to become
apart of the nephric filtrate.
2. Tubular Reabsorption:
 Selective transfer of essential solutes back into the blood through
active transport. Molecules the body still needs.
 Proximal tubule, ascending loop of Henle, and distal tubule
3. Tubular Secretion:
 Movement of wastes from the blood into the nephron through diffusion.
 15% of the molecules stay within the nephric filtrate and are removed
via the bladder.
 Proximal tubule, distal tubule
4. Water Reabsorption:
 Removes water from the filtrate and returns it to the blood.
 Proximal tubule, descending loop of Henle, distal tubule, and
collecting tube.
Kidney Reabsorption:
 Glucose, amino acids, vitamins, and minerals are absorbed by active
transport.
 Change in solute concentration as Cl- is attracted to the + blood causes
the tubule to become hypotonic and the blood hypertonic.
Hormonal Control of Water Reabsorption: Urine Formation.
Hormone: Anti Diuretic Hormone (ADH)
Source: Posterior end of the Pituitary Gland
Trigger: decreased solute concentration in the blood and osmotic pressure.
Released: blood
Target: Proximal tubule, descending loop of Henle, distal tubule, and collecting
tube.
Effect: increased water reabsorption.
Hormone: Aldosterone
Source: Adrenal Cortex
Trigger: increased solute concentration in the blood and osmotic pressure.
Released: blood
Target: Proximal tubule, ascending loop of Henle, and distal tubule
Effect: Reabsorbs Na ions (Na pump) into the blood
Kidney Diseases:
 Diabetes Mellitus: sugar diabetes, body is not producing enough insulin,
sugar is not reabsorbed, causing a greater loss of water.
 Diabetes Insipidus: cannot produce ADH to regulate water reabsorption.
 Kidney stones: precipitation of mineral solutes in the blood break the
kidney tissue.
 Bright’s disease: protein found in the urine
Case Study: Comparing Solutes in Plasma, Nephron, and Urine
Micropipettes were used to draw fluids from the Bowman’s capsule, the
glomerulus, the loop of Henle, and the collecting duct. Solutes in the fluids were
measured. The resulting data are displayed in Table 1.
Table 1 Solute Concentrations in Various Parts of the Kidney
Solute
Bowman’s
Glomerulus
Loop of
Capsule
Henle
Protein
0
0.8
0
Urea
0.05
0.05
1.50
Glucose
0.10
no data
0
Chloride Ions
0.37
no data
no data
Ammonia
0.0001
0.0001
0.0001
Substance X
0
9.15
0
Quantities are in g/100ml
Technologies:
 Dialysis:
Collecting
Duct
0
2.00
0
0.6
0.04
0
Breathing and Gas Exchange:
Pulmonary System:
Bronchiole
Alveoli:
Artery
Vein
* surface area
Alveolus
(Alveoli)
Composition of Air:
Compound
N2
O2
CO2
High pressure to Low pressure
Forces air into the lungs
Inhaled Air
78%
21%
0.04%
Exhaled Air
78%
16%
5%
Breathing Centre:
Acidity(low pH) & High Temperature
High blood CO 2
No Nerve Impulse
Low blood O 2
Breathing Centre
Medulla
Breathing
impulse
Muscles
Breathing Muscles
Relax
Elastic Recoil
Of Cartilage, Alveoli,
& Lung
Contraction
Nerve Impulse Inhibiting Medulla
Decrease in Lung/Chest
Volume
Increase in Lung Volume
Stretch Receptors
Decrease Lung Pressure
Inhalation
Inflated Alveoli
Increase in Lung Pressure
Exhalation
Deflated Alveoli
Stops Impulse
Removes
Inhibition of Medulla
Chemoreceptors: send an impulse to the medulla initiating the breathing process.
Stretch Receptors: (inflated) inhibit the nerve impulse to the ribs. (deflated) enables
chemoreceptors to signal the medulla
Breathing Volumes
Residual (Dead) Air: air needed to maintain the inflation of the lung
Tidal Volume: normal breathing (10%)
Inspiratory Reserve Volume: inhale deeply as much as one can
Expiratory Reserve Volume: exhale deeply as much as one can
Vital Lung Capacity: Tidal, inspiratory, and expiratory reserve volumes.
Total Lung Capacity: All capacities together.
Case Study: Measuring Respiratory Volumes
Patient
Tidal Volume
(mL)
Vital capacity
(mL)
1 (normal)
2
3
4
5
500
500
400
550
550
5 000
4 000
3 000
5 000
6 000
Hemoglobin: last from 110 to 120 days
Hb (red)
carries O2 – 4 sites
Hb
Breakdown
Bilirubin (yellow)
Iron Containing
Molecule
Bile
Haem (hem)
Globin (protein)
Yellow/Brown
Feces
Kidney
Yellow
Urine
Deficiency
Anemia
Gas Exchange:
Oxygen Deficiency:
Short Term:
1. Increased breathing rate and depth
2. Increased heart rate
Long Term
1. Increased Hb production (red blood cells).
Respiratory rate
of patients at rest
(breaths/min)
18
20
38
17
17
Unit 6: Circulatory and Immune System:
Transport or Circulatory System:
Pulmonary Circulatory System:
o Carries deoxygenated blood from the heart to the lungs and oxygenated
blood back to the heart.
Systemic Circulatory System:
o Carries oxygenated blood from the heart to the body and deoxygenated
blood back to the heart.
Blood Vessels:
 Artery: white color, carry blood away from the heart.
o Strong, thick muscular walls, contains three layers.
o Has a pulse, carries oxygenated, bright red blood.
o Carries blood at high pressure and contains no valves.
o Found deep below the surface.
 Arteriole: tiny vessels that carry oxygenated blood away from the arteries
and into the capillaries.
 Capillary: fluid moves into and out of the capillaries with gases and
nutrients.
o Thin permeable walls.
 Venule: move deoxygenated blood back to the veins.
o Lower blood pressure because they are further from the heart.
 Vein: bluish red color, carry blood towards the heart.
o Weak, thin non-muscular walls, contains three layers.
o No pulse and has low blood pressure.
o Contains valves because pressure is low and uses skeletal muscle
movement to move blood back up towards the heart.
o Found near the surface.

Skeletal Muscle Pump:
Cardiac or Heart Muscle:
 Muscle tissue contracts without any nervous impulse (myogenic muscle)
and needs to be regulated.
 Cardiac nodes control and regulate the simultaneous contraction.
o Sino-Atrial (S-A) Node: the main regulator or pacemaker of the
heart that is able to develop an electrical charge that will cause the
atria to contract as a single unit.
o Atrial-Ventricular (A-V) Node: tissue that detects the contraction
and after a slight pause it develops an electrical charge
(depolarization) of its own.
RA
S-A Node
LA
A-V Node
Bundle of His
RV
LV
Purkinje Fibres
Heart Structure:
Chambers:
 Right Atrium: receives blood from the body (deoxygenated)
 Right Ventricle: sends blood directly to the lungs (deoxygenated)
 Left Atrium: receives blood from the lungs (oxygenated)
 Left Ventricle: sends blood to the entire body (oxygenated)
Valves:
 Tricuspid Valve: connects the right ventricle to the right atrium.
 Prevents blood from flowing back into the atrium when the ventricle
contracts.
 Bicuspid Valve: connects the left ventricle to the left atrium.
 Prevents blood from flowing back into the atrium when the ventricle
contracts.
 Semi-lunar Valves: prevent the back flow of blood from the arteries to the
ventricles.
 Pulmonary Valve: prevents deoxygenated blood from back flowing
from the pulmonary artery to the right ventricle.
 Aortic Valve: prevents oxygenated blood from back flowing from the
aorta to the left ventricle.
Septum: divides the right ventricle from the left ventricle.
Blood Vessels of the Heart:
 Coronary Arteries: the blood vessels of the heart, provides oxygen and
nutrients to the heart tissue.
 Pulmonary Artery: carries blood to the lungs for oxygen (deoxygenated).
 Pulmonary Vein: carries blood to the heart from the lungs (oxygenated).
 Aorta: the main artery of the body arising from the left ventricle of the
heart.
 Inferior Vena Cava: large vein that leads into the heart with blood from
the lower body.
 Superior Vena Cava: large vein that leads into the heart with blood from
the upper body.
Pericardium: membranous sac of fluid found around the heart to reduce friction
and protect the heart as it works.
Major Blood Vessels:
 Hepatic Portal Vein: blood rich with food material from the intestinal walls
traveling to the liver.
 Hepatic Artery:
 Hepatic Vein: blood (deoxygenated) the travels from the liver (without
food material) back to the heart.
 Carotid Arteries: left and right in the neck, supplies blood to the neck and
brain.
 Jugular Veins: left and right in the neck, drains blood from the neck and
brain.
 Renal Artery:
 Renal Vein:
 Gastroduadenal Artery: connects the hepatic artery to the small
intestine.
Mechanics of the Heart:
 Pulse: the movement of the arterial walls due to surges of blood.

Vasoconstriction: narrowing of a blood vessel. Less blood goes to the
tissues when the arterioles constrict. Caused by low blood volume or
increased arteriolar resistance due to plaque or muscle contractions.

Vasodilatation: widening of the diameter of the blood vessel. More blood
moves to the tissues when the arterioles dilate.

Control:
Brain
* S-A Node
Pace Maker
Parasympathetic NS
Sympathetic NS
(Slows)
(Speeds)
Atria
A-V Node (delays impulse)
Ventricles
Spinal Cord

Mechanics:
1. Atrium relaxed (diastole) and fills with blood from the S.V.C. and I.V.C.
2. Atrium contracts (systole) and forces blood through the A-V valves
into the ventricle which is relaxed (diastole).
3. Ventricle contracts (systole). Blood tries to escape to the atrium (back
flow) but gets caught in the valve flaps causing the A-V valves to snap
shut. (1st heart beat ~ lub). Blood is now forced out the pulmonary
artery or aorta opening the semi-lunar valves which causes the arteries
to stretch.
4. Ventricle relaxes (diastole). Blood pressure decreases and blood
attempts to back flow because of gravity and the elastic recoil or the
arteries. This blood gets caught in the semi-lunar valves which snap
shut. (2nd heart beat ~ dub).

Electrocardiograph: Measures the electrical activity of the heart.
Systolic Pressure (heart contracts)
Diastolic Pressure
Heart relaxes
Blood Pressure and Capillary Exchange
 Blood pressure is necessary for circulation and fluctuates within normal
ranges. Measured in the arteries
 Factors involved with Blood Pressure:
 Blood Volume: amount of blood. Hemorrhaging (blood loss) can
cause a drop in blood pressure.
 Heart Rate and Force
 Arteriolar Resistance: vasoconstriction increased blood pressure
vasodilatation decreased blood pressure
 Control of Blood Pressure:
o Blood pressure sensed by baroreceptors or stretch receptors
found in the aorta and carotid arteries sends messages to the
medulla oblongata.
o Osmotic Pressure: pressure exerted on the wall of a semi
permeable membrane resulting from differences in solute
concentration sends information to hypothalamus.

Sphygmomanometer: measures blood pressure using mm
Mercury (mm Hg) Ex: 120 / 70 mm Hg
Cardiac Output:
 Humans have about 5 L of blood in an adult
 Cardiac Output: the amount of blood pumped from the heart each
minute.
o Cardiac output = stroke volume X heart rate
 Stroke Volume: the quantity of blood pumped with each beat of the heart.
o Most individuals pump about 70 ml of blood per beat while resting.
o Stronger hearts pump more which results in lower heart rates.
CO = SV x HR
5 L = 50ml/beat x 100 beats/minute
Heart Diseases or Disorders:
Technologies:
 CT scan
 CAT scan
 MRI scan
 Angioplasty
Components of Blood:
Whole Blood
Plasma (Liquid)
55%
*cannot pass through a capillary
Proteins ~ Albumins & Globulins
(antibodies)
Smaller Proteins ~ Insulin
Organic Molecules (G, AA, FA)
Glycerol, Vitamins
Urea
Mineral Salts
Water
Mineral Ions
*can pass through a capillary
Cell Component
Bone Marrow ~ Stem Cells
Erythrocytes
Red Blood Cells
Hemoglobin which transports O2
45%
Leucocytes (Leukocytes)
White Blood Cells
Larger / Less than RBC
Immunity Cells
- engulf organisms
- produce antibodies
<1%
Platelets (Thrombocytes)
Very small and rare
Blood Clotting
Blood Types: ABO
 Antigen: proteins found on cells ~ identification marker
 Antibody: proteins found in plasma that react with specific antigens
RBC
Antigen
A
Blood
Type
Antibody
Potential
Whom it
can be
Donated
Whom it
can be
Received
A
Anti B
A, AB
A, O
Anti A
B, AB
B, O
-
AB
A, B, O, AB
nd
2 most
common
B
rd
B
3 most
common
A&B
AB
Universal
Recipient
Least
common
-



A, B, AB, &
O
O
Universal
Donor
Sensitized Blood: blood has developed antibody potential
For Compatible Transfusions: must match donor’s antigen with
recipient’s antibodies
Agglutination: clumping of blood caused by the antibodies attacking the
antigens.
Rhesus Factor: Rh -/+
Antigen
RBC
R
Most common
O
Anti A and
B
Blood
Type
Antibody
Potential
Whom it
can be
donated
Whom it
can be
received
Rh +
-
Rh +
Rh + & Rh
-
Anti R
Rh + & Rh
-
Rh -
Most common
-
Blue Baby Syndrome:
Rh -
Lymphatic System
 Collects the excess fluid and proteins that causes swelling in the tissues
(edema).
 Fluid and proteins are returned to the circulatory system by way of the
lymphatic system.
 Lymph Nodes: enlargements located at intervals along the lymph vessel
that house lymphocytes (white blood cells). ~ swell when sick.
 Fluid moves as a result of osmotic pressure, gravity, and absorption.
Lymph node
Lymph Vessel
The Immune System:
 A system of non-specific and specific defence mechanisms.
Lines of Defence:
1. Skin and Mucus Membranes: (barriers)
 Oil, sweat, mucus, and tears contain chemicals that kill or capture
bacteria.
2. Non-specific Defence (Cell-Mediated Immunity):
 White Blood Cells: Macrophages, neutrophils, & monocytes
o Phagocytes (neutrophils & Monocytes) eat other cells or
objects found in the body using phagocytosis.
o Natural Killer Cells target the body’s own infected cells or that
have become cancerous.
 Inflammatory Response:
o Damaged tissue release histamine which cause blood to flow to
the area (swelling and pus formation) and could cause the body
to raise its temperature.
 Allergies: overreaction to harmless cells.
3. Specific Defence (Antibody-Mediated Immunity):
 Immune Response: a recognization system that distinguishes “self”
from “non-self”.
 Production of antibodies that circulated around the body in blood and
lymph fluid. Protects against bacteria and viruses.
 Cells destroy host cells infected by protozoans, fungi, bacteria, and
viruses as well as cancer cells and foreign tissues.
 B Cells (from bone marrow) ~ produce antibodies
 T Cells (from thymus gland)
Immunological Memory: enables a quick response to reinfection by the same
antigen. Vaccines: adding a weakened version of the antigen to the body so that
it develops antibodies and a memory to combat it in the future.
Unit 7: Energy and Matter Exchange in the Biosphere
Biosphere: Stable environment in which nonliving and living things interact and
in which minerals are recycled and energy flows in and out.
Closed System:
 System is self-contained
 Nothing is needed from an outside source ~ raw materials or waste
removal.
Abiotic and Biotic components
 Abiotic or Nonliving Components ~ chemical, geological, or physical
factors.
 Ex: soil, minerals, temperature, water, energy, and atmosphere.
 Biotic or Living Components ~ life forms
Biotic Influences in the Biosphere:
 Solar energy powers the cycling of biochemical matter trapped and release in
living organisms.
Input energy solar energy
Biochemical Cycles
Output Energy heat
The Biogeochemical Cycles:
1. Hydrological Cycle:
 As water travels through the biotic and abiotic components of the
biosphere, it carries much material with it, including chemical nutrients.
This links the hydrologic cycle with the biogeochemical cycles, through
which nutrients travel.
 Large specific heat capacity holds and releases a great deal of heat.
 Hydrological cycle connects ecosystems together
 Metabolic reactions take place within water.
 Supply of hydrogen and oxygen
1.
2.
3.
4.
5.
6.
7.
evaporation
condensation
precipitation
infiltration
runoff (percolation)
transpiration
storage (in atmosphere, ice and snow, freshwater bodies, and oceans)
2. The Carbon Oxygen Cycle:
 Biotic component ~ complementary processes of photosynthesis and
cellular respiration. Decomposers release organic material back into
carbon dioxide.
 Abiotic component ~ carbon dioxide is mostly stored as carbonic acid
in water and the release via volcanic eruptions
 Disruption by human activity ~ release of stored organic (deforestation)
and inorganic (fossil fuels) carbon. ~ greenhouse effect
3. The Nitrogen Cycle:
 The nitrogen cycle is a biogeochemical cycle that shows how nitrogen is
converted into different forms as it is transported through the air, water,
and soil. All organisms require nitrogen to make proteins and genetic
material (DNA).
 Nitrogen in the Air: Nitrogen gas (N2) makes up 78.1 percent of Earth’s
atmosphere by volume. Most organisms, however, cannot use
atmospheric nitrogen.
 Nitrogen in the Water: Nitrogen gas is removed from the atmosphere via
nitrogen-fixing cyanobacteria, which convert it into a form plants can use—
ammonium (NH4+). Some types of aquatic bacteria then convert the
ammonium into nitrate (NO3), which plants can also use.
 Nitrogen in the Soil: Nitrogen fixation or Nitrification is the conversion
of nitrogen gas (N2) into nitrates (NO3-) and ammonium ions (NH4+), which
then can be used by plants. Nitrogen-Fixing bacteria convert atmospheric
nitrogen to nitrates Ammonification ~ process where nitrogen is released
from decaying protein as ammonia. Other bacteria convert nitrate back
into nitrogen gas via denitrification. Lightening causes nitrogen to react
with oxygen to produce nitrates to be dissolved in the soil solution.
4. The Phosphorous Cycle:
 The phosphorus cycle is a biogeochemical cycle that shows how
phosphorus is converted into different forms as it is transported through
the water and soil. All organisms require phosphorus as a part of cellular
DNA and ATP (the energy carrier essential to all cells).
 Phosphorus in the Air: Unlike carbon, nitrogen, and sulfur, phosphorus
does not cycle through the atmosphere.
 Phosphorus in the Soil: Weathering gradually releases phosphorus
trapped in rocks and makes it available to organisms. Plants and algae
can only use phosphorus in the form of phosphate (PO 43). Phosphorus is
scarce in the environment. This keeps the growth of producers in balance,
but it can also limit the growth of crops.
 Phosphorus in the Water: The growth of algae in aquatic ecosystems is
limited by the amount of available nutrients. Because it is scarce in the
environment, excess phosphorus in aquatic ecosystems can result in algal
overgrowth, known as an algal bloom.
5. The Sulfur Cycle:
 The sulfur cycle is a biogeochemical cycle that shows how sulfur is
converted into different forms as it is transported through the air, water,
and soil. All organisms require sulfur as an important component of
proteins and vitamins.
 Sulfur in the Air: The decomposition of organic matter, volcanic offgassing, and human activities all release sulfur into the atmosphere. Rain
and snow soon return sulfur to Earth’s surface via acid deposition.
 Sulfur in the Water: Plants and algae take up sulfur in the water-soluble
form of sulfate (SO42).
 Sulfur in the Soil: Decomposers quickly return sulfur to the soil or air as
hydrogen sulfide (H2S). Soil bacteria use sulfur compounds in
photosynthesis or cellular respiration, thus playing an essential role as
they convert one form of sulfur to another. Some sulfur is taken out of
rapid cycling when bacteria convert sulfur to forms that are layered down
as sediments, eventually becoming part of rocks.
Ecology:
 The study of the flow of energy and matter through an environmental system.
Open System:
 System is depended upon an outside source ~ influx and removal of
materials.
 Ex: human cells, ecosystems etc.
Dynamic Equilibrium or Homeostasis:
 All parts of a system must adjust to any change made by one component
to keep balance.
Ecosystems:
 Semi-closed system where matter is recycled between abiotic and biotic
components.
 Driven by energy driven ~ eventually lost. ~ open system
The Laws of Thermodynamics:
1. Energy cannot be created nor destroyed, only transformed from one form
to another.
 Energy Input = Energy Output
2. During an energy transformation, some of the energy produced (heat) is
lost from the system.
 Energy Input = Energy Output + Waste Energy (Heat)
All organisms need:
 Organic molecules and energy
Energy Flow in the Ecosystem:
 Autotrophs ~ Self-Feeder, organisms capable of obtaining their energy and
matter from the physical environment.
 Producers: photosynthesis or chemosynthesis ~ formation of
carbohydrates from chemical energy and not light energy. Ex: nitrogenfixing bacteria
 Heterotrophs ~ organisms that obtain food and energy from autotrophs or
other heterotrophs.
 Consumers: organisms that break down living tissue.
 Primary: herbivores (organisms that only eat producers)
 Secondary: omnivores (organisms that eat producers and primary
consumers)
 Tertiary: omnivores and carnivores (organisms that only eat consumers)
 Decomposers ~ bacteria and fungus that break down the remains or waste
of other organisms to obtain their organic nutrients.
Trophic Levels:
 Locates the position of an organism during its energy – seeking activities.
 The number of energy transfers an organism is form the original solar energy
entering the system.
Food Chain: rule of 10
!00%
0.001%
Sun
Top
10%
1%
0.1%
Plant
Grasshopper
Bird
Producer
Primary Consumer
st
1 Trophic
nd
2 Trophic Level
Herbivore
Snake
Secondary
rd
3 Trophic
Carnivore
0.01%
Owl
Tertiary
Quaternary or
th
4 Trophic
5
Th
Trophic
Food Webs:
A series of interlocking food chains representing the transfer of energy through
various trophic levels in an ecosystem.
th
4 Consumer
Sun
nd
2 Consumer
st
1 Consumer
Producers
Decomposers
Heat
Types of Ecosystems:
1. Terrestrial Ecosystems:
 Classified into major types called biomes.
 Each biome has a distinctive climate (water and heat), plant and animal life.
 Tundra: arctic, short growing season, permafrost, low precipitation, seals,
lichen, caribou.
 Boreal Forest: south of tundra, wet & acidic soil, more precipitation,
spruce, moose.
 Mixed Deciduous Woodland Forest: rich fertile soil, most precipitation,
maple, weasels, woodpeckers.
 Grassland: less precipitation, soil holds less water, hawks, rattlesnakes,
bison.
2. Aquatic Communities:
 High specific heat capacity and the high thermal conductance (rate at
which heat passes through water) of water allows a much more stable
temperature than in the terrestrial ecosystem.
 Divided into two categories depending upon the amount of salt dissolved
in the water (salinity); Freshwater and Saltwater.
Marine Communities:
 More diverse than freshwater communities.
 Divide it into zones based upon water depth.
Freshwater Communities:
 Lakes have three layers:
 Littoral region: light can reach the bottom resulting in a large
community of producers and consumers.
 Limnetic region: open water that allows for photosynthesis but
doesn’t allow rooted plants to exist.
 Profundal region; Insufficient light for photosynthesis and contains
only scavengers.
Littoral
Limnetic
Profundal
Ecological Pyramids:
 Represent energy flow in food chains and webs.
 Based on the idea that energy is lost at each trophic level.
 Energy lost due to heat, activity, growth, and reproduction.
1. Pyramid of Numbers:
 Energy pyramid based on the numbers of organisms in each trophic level.
th
1 4 consumer
rd
75 3 consumer
nd
500 2 consumers
st
50 000 1 consumers
100 000 producers

st
Sometimes a pyramid of numbers can be inverted because many 1 consumers can live on
one producer.
2. Pyramid of Biomass:
 Energy pyramid based on the dry mass of tissue of the organisms at each
trophic level.
 Measured in kg
25kg
500kg
12 000kg
200 000kg

3. Pyramid of Energy:
 Energy pyramid based on the amount of thermal (heat) energy produced
at each trophic level.
Measured in KJ/m²/year
100
1 000
15 000
100 000
20 000
Factors Interfering with Ecological Pyramids:
 Seasons ~ decreased amount of solar radiation in winter months changes the
number of producers.
 Natural Changes ~ retreating glaciers, floods, volcanic eruptions,
earthquakes, and fires.
 Human-Induced Changes ~ Fires, flooding due to dams, pollution, hunting
and fishing, monocultures ( growing a single plant species to the exclusion of
others), and pesticides (DDT and Peregrine falcon).
Biological Amplification:
 The buildup of toxic chemicals in organism as tissues containing the chemical
move through the food chain.
Scientific Explanations for Changes in Atmospheric Conditions:
Beginning: anoxic environment (no oxygen)
 Big Bang which released radiation, particles, and clouds of atoms creating
stars.
 New stars (SUN), with the help of gravity, created planets.
 Soon life appeared on Earth in the form of primitive single cell
photosynthetic organisms.
Middle:
 Evolution was played out the same time the continents were drifting.
 Single cell organisms with nuclei appeared e.g.; algae (plants) and
protozoa (animals)
 Organisms began to live together in colonies resulting in invertebrate
animals and more complex algae.
 Plants moved onto land and followed by animals.
Current: (Biosphere Equilibrium)
 Atmosphere is composed of solid particles, water vapour, and
atmospheric gases:
 Greenhouse Effect:
 Carbon Dioxide absorbs the heat and acts as a heat trap and
results in the warming of the Earth’s temperature.
 Human activity has caused an influx of carbon dioxide.
 Ozone Layer:
 Contains the ozone layer absorbing ultraviolet radiation (O2 ~~> O3)
 Depletion is the result of the release of Chloroflurocarbons (CFCs),
which are broken down by UV light allowing chlorine molecules to
combine and trap thousands of ozone molecules.
Unit 8 Ecosystems and Population Change
Organizational Levels of the Biosphere:
 Organism: one individual (single or multicellular)
 Population: group of individuals of the same species located in a
particular area.
 Species: individuals which are genetically similar enough to
produce viable and fertile offspring.
 Sexual reproduction at this level allows for variation and genetic
recombination.
 Variation is any genetic, behavioural, and physical difference
between individuals in a population or between parents and
offspring, allows for the continuation of the species in changing
environments, and is source of new adaptations (mutations).
 Community: many populations interacting together as they coexist in
the same area.
 Ecosystem: biotic (living) and abiotic (non-living) characteristics
combine and interact together.
 Biotic Components: community (living factors)
 Abiotic Components: chemical, geological, or physical factors
(environment) that influence living organisms.
 Biosphere: many ecosystems (terrestrial and aquatic) interacting
together
 Biogeochemical and Hydrological Cycles connect the
ecosystems together.
Taxonomy: Classification of Living Things (Domains, Kingdoms, Phyla,
Classes, Order, Family, Genus, Species)
 Three Domains
 Bacteria: prokaryote, unicellular organisms, lack a membrane-bound
nucleus, reproduce asexually, heterotrophic by absorption, autotrophic
by chemosynthesis or photosynthesis, move by flagella.

Archaea: prokaryote, unicellular organisms, lack a membrane-bound
nucleus, reproduces asexually, many are autotrophic by
chemosynthesis, unique rRNA sequence, distinctive cell membrane.

Eukarya: eukaryotic, unicellular to multicellular organisms, membranebounded nucleus, sexual reproduction, nutrition diverse.

Six Kingdoms:
 Archaea: single celled, prokaryote cells living in extreme
environments.
 Bacteria: single celled, prokaryote cells living in a wide range of
habitats.
 Protista: unicellular and multicellular organisms that are eurkaryote
(autotrophs and heterotrophs).
 Fungi: obtain food by digesting and absorbing food outside of their
tissues, sessile, no chloroplasts.
 Plantea: photosynthesizers, sessile, contain chloroplasts
 Animalia: consumers (decomposers) that move and ingest food
Binomial Nomenclature:
 Linnaeus used Latin and Greek terminology to name organisms (universal
understanding)
 Genus and Species
Dichotomous Keys:
 Identification key that uses series of paired comparisons to sort organism
into smaller and smaller group.
Climate and Biomes
 Climate: average weather conditions (temperature and rainfall) in a
particular region over a period of time affected by unequal heating of the
earth (sphere), snow and ice cover, proximity to water, local geography,
currents, and seasons (tilt).
 Biomes: terrestrial ecosystems types that are directly affected by climate.
(Ex: taiga, tundra, desert, etc.)
o Mix of plants and animals that are adapted to living under these
climate conditions.
Habitat:




The environment in which an organism survives.
Limited by climate, water, soil conditions, and vegetation.
Geographic Range:
o The total area, extent of locations of habitat, where and organism
may live naturally.
Ecological Niche:
o An organism’s profession, role, trophic level or feeding level
o It is the total environment and way of life of all the members of a
particular species in the ecosystem
o Involves factors like feeding habits, number of offspring per birth,
interspecies (different species) relationships, effect on soil, etc.
o E.g. producer/consumer/decomposer, predator, prey, parasite.
Limiting Factors: Components of an ecosystem that can limit or restrict the
number of individuals within a population. They can influence an organism
distribution and range.
 Abiotic Limiting Factors:
o Non-living components or requirements like soil type, moisture,
humidity, temperature, altitude, pH levels etc. that can influence the
growth of plants and thus, animals.
 Biotic Limiting Factors:
o Populations can grow fast when more births occur than deaths
o Populations can level off and be constant if births roughly equal
deaths
o Populations can also drop or die off if there are more deaths than
births.
o Determined by:
 Competition for Resources: food, space, water, niche, mates
 Intraspecific competition for resources among
members of the same species
 Interspecific competition for resources among
populations

Predators:
 Predator consumes prey (deer eating grass or wolf
eating deer)
 More prey, more predators etc.

Parasites:
 Parasite derives nourishment from a host that is
harmed by the relationship.
 More hosts, more parasites
Sampling Population Size and Density:
 By sampling a portion of the population one can get an estimate of the
whole population size. Biologist use transects and quadrates to calculate
density which is used to estimate the size of populations. Random
locations.
 Transects are long, narrow, rectangular area marked out in a study area
where one counts all the individuals of each species. (5m x 100m)
 Quadrates are square areas used to count the individuals of one species.
(1m x 1m).
 Density: the number of individuals per unit of volume or area.
Environmental Changes:
 Organisms are adapted to their environment and when there is a change
in those environmental conditions they have to do one of three things:
1. Migrate to a more suitable environment. E.g. birds, seeds.
2. Die out as a species.
3. Adapt as a species or Evolution
Evolution:
 Cumulative changes in characteristics of populations of organism in
successive generations.
 Environment exerts selective pressure on the population not the
individual.
 Certain characteristics are better suited for the environmental
conditions are selected for and ones that are not are selected against.
Adaptation:
 An inherited trait or set of traits that improve the chances of survival and
ultimately lead to a greater chance of reproducing. ~ genes or DNA
 Variation in traits can provide a population with flexibility if the environmental
conditions change.
 Selective Advantage: characteristic that improves an organism’s chances of
survival in a changing environment as a result of a mutation.
 Ex: ground squirrel blood factor that combats rattlesnake venom
Types of Adaptations:
 Structural:
 The most obvious adaptation.
 Involves modifications to the organisms’ body shape or parts.
 Functional like ducks have webbed feet for swimming.
 Deceptive like camouflage
 Warning coloration: bright colors and patterns to warn other
organism like a bee
 Mimicry: color pattern or body shape which resembles a harmful or
distasteful organism.
 Physiological:
 Involves the chemical processes organisms use to survive and be
successful in their environment.
 Enzymes: special protein structures that control body functions like
temperature, digestion, muscle contraction, etc.
 Example: snake venom
 Pheromones: chemicals secreted by organisms to influence the
behaviour of another organism of the same species.
 Example: line of ants

Behavioural:
 Quickest adaptation to environmental change.
 Involves a behavioural response to a specific stimulus.
 Hibernation, migration, hunting, reproductive rituals, attraction to light.
 Ex: dogs, plants, people.
Evolution of the Theory of Natural Selection:
Leading theory behind the mechanisms of evolution
1. Buffon’s Histoire Naturelle:
 Suggested that the earth was older than 6000 years.
 Noted similarities between humans and apes and suggested that they
might have a common ancestor.
2. Cuvier’s Fossils:
 Developed the science of paleontology which studies ancient life by
looking at fossils and the residue of geological changes in time (volcanoes
etc.)
 Oldest fossils are in deeper layers.
3. Lyell’s Principle of Geology:
 Geological changes and processes operate at the same rate now ands
they did in the past. (Biblical stories ???)
4. Lamarck’s Theory of Evolution: 1801
 One attempt to explain evolution had three parts:
1. The Theory of Need:
 Organisms produce new organs or parts as they need them.
 Ex: ancestor of snakes had a short body and legs but as the land
changed it became necessary for them to stretch into narrow spaces.
2. The Theory of Use and Disuse:
 Organs and parts only remain healthy and strong as long as they are
used and disappear when they are no longer used.
 Ex: snake’s legs disappeared because the snake didn’t use them
anymore.
3. The Theory of the Inheritance of Acquired Characteristics:
 All the changes that an organism makes in life are passed onto its
offspring.
 Ex: snakes whom lost their legs in life would produce legless offspring.
5. Charles Darwin and Alfred Wallace’s Theory of Natural Selection: 1859
1. Overproduction:
 All organisms produce more offspring than can survive.
 Ex: Fish
2. Struggle for Existence: (Competition)
 Due to this overproduction, organisms constantly struggle for
existence.
 Ex: My brother the hamburger
3. Individual Variation:
 Individuals within a species will vary.
 Genes the basis of natural selection.
4. Survival of the Fittest:
 The best adapted, or fittest, individuals will survive.
 Organisms, which survive, will pass the variations onto their
offspring.
5. Origin of New Species:
 Over numerous generations, new species arise by the
accumulation of inherited variations.
 Species becomes a group of organisms which normally interbreed
in nature to produce fertile offspring.
Speciation: the formation of a new species..
1. Transformation: a new species gradually develops as a result of
mutation and adaptation to changing environmental conditions and the old
species is replaced.
Ex: ancestral mammoths to steppe mammoths to wooly
mammoths.
2. Divergence: one or more species, with different characteristics adapted to
different environmental factors, arise from a parent species that continues
to exist.
Ex: Ancient bear evolved into polar bear, grizzle bear, and brown
bear.
 Isolation or Barriers that Lead to Divergence:
 Geographic Isolation: A part of a population becomes isolated
by the environment causing the changes to the amount of
variation found in the gene pool.
 Adaptive Radiation: evolution of many new species from a
common ancestor in new environments. New species fit into
different niches and are then adapted to that different
environment but from the same ancestor ex: finches found
on many islands.
 Reproductive Isolation: Any resulting barrier to interbreeding
which limits variation and produces new species. Ex: dogs
Pace of Evolution:
 Gradualism: changes in populations occur in a steady, linear fashion
where change is consistent. (Contradicted by fossil record)
 Punctuated Equilibrium: long periods of equilibrium where there is little
change and then is interrupted by periods of speciation.
Evidence for Evolution:
1. Fossil Record:
 Skeletal remains preserved as fossils documents the gradual change that
has occurred among species.
 Fossils are formed in sedimentary rock and deposited in layers.
 Many extinct organisms documented in deeper layers.
 Fossils provide direct evidence of the pathways taken by living organisms
in their evolutionary history or phylogeny.
 Older organisms are less complex than newer ones.
 The number of early forms of organisms was small.
 Gaps in the record prevent a complete pathway of evolution.
2. Biogeography:
 Distribution patterns of organisms have been affected by geographical
events:
 Theory of Plate Tectonics:
 The earth’s plates are constantly moving and have caused the continents
to drift apart.
 Separated and isolated species.
 Climate:
 Different climates have caused different species to evolve in order for
them to survive the environment.
 Convergent Evolution: the process by which distantly related organisms
develop similar characteristics as a result of being subjected to similar
environmental pressures.
 Ex: dolphin, salmon, whale
 Ex: Australia, marsupial animals evolved.
3. Embryology:
 The development of the embryo is similar for all vertebrates which suggests a
relationship between species or that they all evolved from the same ancestor.
4. Physiological Evidence:
 Vestigial Organs: seemingly useless organs that are also found in related
species.
 Remnants of structures in ancestors that are no longer selected for.
 A contradiction to Lamarck’s Theories.
 Ex: Human appendix or tailbone.
 Similar physiology can also indicate a relationship between two species.
 Ex: kidney waste in birds is similar to that of reptiles.
 Ex: hormones from sheep and pigs can be injected into humans ~ insulin.
5. Biochemical Evidence:
 Similar molecules that make up different living things suggest relationships.
 DNA analysis, humans share 98% of the same genetic information as
chimpanzees.
 Amino acid sequencing.
6. Homologous and Analogous Structures:
 Homologous Structures: similar origins but difference uses in different
species. Ex; front flipper of a dolphin and front paw of a dog.
 Indicate similarities in ancestry.
 Analogous Structures: similar in function and appearance but not in origin.
Ex. Wing of a bird and insect.