Download Biology 20 Student Notes Ciculatory System To Evolution_1

Mrs. Paulgaard
Biology 20
Notes & Diagrams
Circulation, Immunity, Biosphere, Ecology,
Taxonomy, & Evolution
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:
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.
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.
 Control: Impulses from the medulla oblongata (parasympathetic) slow down the rate and
spinal cord (sympathetic) speed up the rate.
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.
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.

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).
Diastole:
Systole:
Systolic Pressure (heart contracts)
Diastolic Pressure
Heart relaxes

Electrocardiograph: Measures the electrical activity of the heart.
Blood Pressure and Capillary Exchange
 Blood pressure is necessary for circulation and fluctuates within normal ranges.
 High and low blood pressure.
 Hypertension: long term high blood pressure.
 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:
 Aneurysm: fluid-filled bulge found in the weakened wall of an artery that could rupture.
o Stroke is an aneurysm in the brain.
 Atherosclerosis: degeneration of the blood vessel caused by the accumulation of fat
deposits along the inner wall.
 Varicose Veins: distended or bulging veins.
 Angina: chest pains that occur when too little oxygen reaches the heart.
 Murmur: faulty heart valves which permit the back flow of blood into one of the heart
chambers.
 Coronary Occlusion: blockage of a blood vessel due to plague or a clot.
 Anemia: lack of hemoglobin
 Embolism: blood clot that dislodges and is carried by the circulatory system.
 Leukemia: overproduction of white blood cells (immature and non-productive) ~ cancer
of the blood.
Technologies:
 CT scan
 CAT scan
 MRI scan
 Angioplasty
Circulation Case Study:
Red blood cells (erythrocytes) carry oxygen to the cells of the body. A condition called hypoxia
(low oxygen) can result if the number of red blood cells is diminished or if there is a problem with
the hemoglobin within the red blood cells. Study the chart below, and match the condition with the
correct patient. Please note that the information in the chart refers only to the patient’s systemic
circulation.
Patient
Condition
Hemoglobin
(grams Hb/100
mL blood)
1
2
3
4
5
Normal
Hypoxic
Hypoxic
Hypoxic
Hypoxic
15
15
9
16
15
Oxygenated
blood (mL
O2/100 mL
blood)
19
15
9.5
21
19
Deoxygenated
blood (mL
O2/100 mL
blood)
15
12
6.5
13
18
Cardiac
Output
(L/min)
5.0
6.6
7.0
3.0
No information
given.
1. Which patient might be suffering from a dietary iron deficiency? How do you know?
2. Which patient may be experiencing heart failure and thus poor blood circulation? How do you
know?
3. Which patient may recently have experienced high altitude (hiked up a mountain) where air is
lower in atmospheric oxygen? How do you know?
4. Which patient may have been exposed to a poison that prevents the cells from using
oxygen? How do you know?
5. Answer the following questions in relation to Patient 1:
a) How much blood is flowing through the lungs each minute?
b) How much oxygen (in mL) is transported to the lungs each minute? Explain.
c) How much oxygen (in mL) is carried away from the lungs each minute? Explain.
d) Use the answers from b) and c) to calculate the oxygen consumed each minute. Show
and explain all of your work.
Components of Blood:
Whole Blood
Plasma (Liquid)
55%
*cannot pass through a capillary
Proteins ~ Albumins & Globulins
(antibodies)
Smaller Proteins ~ Insulin
Cell Component
Bone Marrow ~ Stem Cells
Erythrocytes
Red Blood Cells
Hemoglobin which transports O2
45%
Organic Molecules (G, AA, FA)
Glycerol, Vitamins
Urea
Mineral Salts
Water
Mineral Ions
*can pass through a capillary
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 Clotting:
Tissue Damaged
Thromboplastin Released
+ Ca
+
Protein in plasma
Fibrinogen (Plasma Protein)
Thrombin
Fibrin (sticky protein threads)
Serum: blood plasma with fibrinogen removed
Blood Types: ABO
 Antigen: proteins found on cells ~ identification marker
 Antibody: proteins found in plasma that react with specific antigens
Antigen
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
RBC
A
2nd most common
B
B
3rd most common
A&B
AB
Universal
Recipient
Least common
-
O
Anti A and B
Most common



A, B, AB, & O
Universal
Donor
O
Sensitized Blood: blood has developed antibody potential
For Compatible Transfusions: must match NOT donor’s antigen with recipient’s
antibodies
Agglutination: clumping of blood caused by the antibodies attacking the antigens.
Rhesus Factor: Rh -/+
Antigen
RBC
R
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
-
Rh -
Blue Baby Syndrome:
 Mom is Rh – and baby is Rh +, baby’s blood enters mom’s blood and causes her to
produce Anti R antibodies, next babies will be miscarried since its blood carries the
antigen and the mom’s immune system rejects it.
Case Study Sheet:
A clever student has sensitized group A blood. She is given 4 containers of blood and told that
one container is type A, another AB, one is B, and the remainder group O. Unfortunately the
labels fell off but she knew that all of the blood samples were sensitized. Her job is to identify
each blood sample’s type. She collects some of her own blood (type A) and separates it and the
4 samples into plasma and cell components.
Sample #1
Sample Cells
Student Plasma
(Anti B)
Student Cells
(A)
Sample Plasma
Sample #2
Agglutination
Sample #3
Sample #4
Agglutination
Agglutination
Agglutination
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.
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 causes 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 recognition 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.
 Antibodies bind with Antigens preventing them from attaching to
receptor sites on healthy cells. ~ Phagocytes then eat them.

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)
o Helper T Cells ~ identify invaders
o Killer T Cells ~ puncture infected cells and kill them.
o Suppressor T Cells ~ turn off the immune system
o Memory T Cells ~ remembers the shape of the antigen
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.
 Autoimmune Disease: antibodies attack the body’s own uninfected cells.
 Antibiotics: chemicals that attack bacterial cell membranes.
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.
 Ex: space station, biosphere, or biodomes etc.
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.
 Holds a vast amount of heat during the day and releases it at night.
 Hydrological cycle connects ecosystems together
 Universal solvent as a result is the medium by which matter is cycled
 High boiling and melting point
 Special adhesive and cohesive properties
 Metabolic reactions take place within water.
 Supply of hydrogen and oxygen
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 (PO43). 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 off-gassing, 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.
Acid Rain:
 Sulfur dioxide and Nitrous oxides are released from fossil fuels and fertilizers.
 Acids can combine with water vapour and return to the earth in the form of acid rain or snow.
 Acids can fall back to earth as dry pollutants.
 Acids react with marble, metals, plastics, and rubber.
 Kills plants, soil bacteria, and fish.
 Can be neutralized with basic soils.
Wind
Sulfuric Acid and Nitric Acid
Wet Acid Deposition
Dry Acid Deposition
Basic Soil Neutralizes
Deep Lakes
Buffered
Ocean
Shallow Lakes
Acidic
Nitric Oxide and Sulfuric Dioxide
Solutions:
 Higher smoke stacks ~ resulted in a local problem turning into an international problem.
 Scrubbers on smoke stacks ~ remove harmful emissions
 Lime added to lakes ~ neutralizes the acid.
 Though legislation has forced solutions.
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.
 Example: bear population is dependent upon deer population or high pulse rate is
dependent upon breathing rate.
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:
 30% of solar energy is reflected (albedo)
 19% of solar energy is absorbed by water vapour & carbon dioxide.
 51% of solar energy is absorbed at the earth’s surface.
 1% to 2% of solar energy is captured by producers
 Photosynthesis makes all the energy available to the community, thus light is the source of all
energy within an 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: nitrogen-fixing 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
Food Webs:
A series of interlocking food chains representing the transfer of energy through various trophic
levels in an ecosystem.
4th Consumer
Sun
Heat
2nd Consumer
1st Consumer
Producers
Decomposers
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.
 Reason why most ecosystems have a maximum of five trophic levels.
 Illustrates the interrelationship between energy, matter, and ecosystem productivity. Tropical
rainforest vs. Desert, Taiga vs. Tundra, etc.
1. Pyramid of Numbers:
 Energy pyramid based on the numbers of organisms in each trophic level.
1 4th consumer
75 3rd consumer
500 2nd consumers
50 000 1st consumers
100 000 producers

Sometimes a pyramid of numbers can be inverted because many 1st 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
Without the continuous supply of solar energy the energy available to maintain the food chain
would eventually run out (lost as heat).
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.
 Produced oxygen and organic molecules like monosaccharides, amino acids, fatty
acids etc from basic elements like nitrogen, sulfur, and phosphorous and compounds
like carbon dioxide and water.
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:
 Nitrogen 78%, Oxygen 21%, Argon 0.9%, Carbon Dioxide 0.03%, and Trace Gases
(Ozone, Methane) 0.01% ~ relatively fixed.
 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.
 5 degree increase in average temperature could cause the ice caps to melt.
 Venus
 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.
 Stratosphere
Geological Evidence for Climate Change
 Deposits of ancient micro-organisms hold clues about the composition of Earth’s
atmosphere and oceans. (Fossil Evidence)
 Stromatolites are fossilized sedimentary structure formed from ancient bacteria that
provide evidence of oxygen formation due to the presence of iron.
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.
 Ex: soil, minerals, temperatures, water, energy, and atmosphere.
 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)
Ex: Humans
Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species

Eukarya
Animalia
Chordata
Mammalia
Primates
Hominidae
Homo
sapiens
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, membrane-bounded
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 species or Genus species
Dichotomous Keys:
 Identification key that uses series of paired comparisons to sort organism into smaller
and smaller group.
Norns belong to the genus Norno and can be divided into eight species that are
generally located in specific regions of the world. Use the dichotomos key to identify the
norns below. Write their complete scientific name (genus + species) in the blank.
Dichotomous Key
1. Has pointed ears .................................... go to 3
Has rounded ears ....................................go to 2
2. Has no tail ............................................. Kentuckyus
Has tail .................................................. Dakotus
3. Ears point upward .................................... go to 5
Ears point downward .
.............go to 4
4. Engages in waving behavior ......... ....... Dallus
Has hairy tufts on ears .............................Californius
5. Engages in waving behavior ............................. WalaWala
Does not engage in waving behavior ....................go to 6
6. Has hair on head ............................................. Beverlus
Has no hair on head (may have ear tufts) .......go to 7
7. Has a tail ............................................. Yorkio
Has no tail, aggressive ............................ Rajus
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.
Ex: Each transect has an area of 20km2 and the entire area of the habitat is 20,000km2. Calculate
the total number of deer found in this habitat based on this data and the diagram provided below.
Ex: If there are 30 bears in a sample area of 500km2, how many bears are there in total in a
habitat that reaches 10,000km2?
Ex: If there are 15 wolves in the sample area of 1000km2 then how big is the total habitat if a total
of 182 wolves are counted?
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.
Mate Selection: A Study Summary
"A Half Century of Mate Preferences: The Cultural Evolution of Values." It's by Buss,
Shackelford, Kirkpatrick, and Larsen, and appeared in the Journal of Marriage and
Family. The authors found that various college students had answered the same
questionnaire in 1939, then ran surveys in 1996. This makes a reasonably consistent
sample of undergraduates over time. In each survey, the heterosexual students were
asked to rank 18 mate characteristics from highest or most desired (1) to lowest or least
desired (18). They are listed in the table below.
Good Cook and Housekeeper
Pleasing Disposition
Sociability
Similar Educational
Background
Refinement and Neatness
Good Financial Prospect
Chastity
Dependable Character
Emotional Stability and
Maturity
Desire for Home and
Children
Favorable Social Status
Good Looks
Similar Religious Background
Ambition and
Industriousness
Similar Political Background
Mutual Attraction and
Love
Good Health
Education and
Intelligence
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.
 Ex: Australia, marsupial animals evolved.

Reproductive Isolation: Any resulting barrier to interbreeding which limits
variation and produces new species. Ex: dogs
 Differences in mating habits
 Physical impossibility
 Seasonal differences
 Chromosome differences
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
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 wisdom teeth 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. 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.
6.



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.