Scientific Method
Name the problem or
question
Form an educated guess
(hypothesis) and make
predictions
Test your hypothesis by
doing an experiment.
Check and interpret
(analyze) your results
Report your results.
Scientific Method
•
Constant – does not change in an
experiment; stays the same through all trials
•
Control – “standard for comparison;” not
tested
•
Independent variable – factor that is being
tested; what the experiment (“I”) is testing
•
Dependent variable – result of the
experiment; what happens because of the test
Characteristics of Life
1.
2.
3.
4.
5.
6.
7.
Made of cells
Reproduce
Grow and Develop
Use energy
Respond to stimuli
Maintain Homeostasis
Genetic Code
Organic Molecules
• Lipids: Fats, Oils, Steroids
• Smallest unit - Fatty Acid & glycerol
• Test: Brown Paper Bag Test
• Proteins: Enzymes, Insulation, Help fight disease
• Look for Nitrogen in the chemical formula or structure!
• Smallest unit - Amino Acids & peptide bonds
• Carbohydrates: Starches and Sugars (GLUCOSE)
• Main Source of Energy
• Smallest unit - monosaccaride
• Test: Iodine
• Nucleic Acids: DNA & RNA, Genetic / Hereditary Info.
• Smallest unit - Nucleotide (sugar, phosphate, nitrogenous
bases)
Ecology Terms
•
Habitat- Place that an organism occupies for shelter.
Includes abiotic and biotic factors.
•
Niche: Role organism plays within an ecosystem.
Community Interactions
1. Competition: organism competes for resources
2. Predation: situation where one organism captures
and feeds on another
3. Symbiosis: relationship where one organism lives
in close association with another.
Symbiotic Relationships
1. Mutualism- Both species benefit (Flower & Bee)
2. Commensalism- One species benefits and the other
is neither hurt nor harmed. (Coral and Clown Fish)
3. Parasitism- One species benefits and the other is
harmed. (Tick and Dog)
Ecology Terms
• Population= Same species, same area
• Community= Different species, same area
• Ecosystem= All Biotic and Abiotic parts
• Producer, Plant, Autotroph= make own food, photosynthesis
• Consumer, Heterotroph= consume other things to get energy.
–
–
–
–
–
Herbivore: only plants
Carnivore: only meat
Omnivore: plants and meat
Scavenger: eat dead material
Decomposer / Bacteria or fungi: Breakdown dead organic material and
return nutrients to the soil
Energy Pyramids
•Shows the flow of energy within an ecosystem!!
10
energy units
owl
100
energy units
1 000
energy units
10%
snake
cricket
10 000
energy units
grass
C3
10%
C2
HEAT
10%
C1
Producers
Greatest number of
organisms, energy and
biomass (amount of living
substance) is found at bottom
of pyramid!
Behavior
• Behavior: Way that an organism reacts to
changes in its internal and external
environment.
• Stimulus: anything that makes an organism
respond. EX: Light, Smell
• Response: A single specific reaction to a
stimulus. EX: Reflex
• Innate Behaviors: Inherited behaviors
Innate Behaviors
• Migration: movement due to seasonal changes.
• Hibernation: Response to cold to conserve energy
• Estivation: Response to heat
• Circadian Rhythm: 24-Hour Routine (day-night)
• Territoriality: Animal defends territory / Reduces
Conflict; uses resources efficiently; controls size of
population  pheromones
• Aggressive behavior: Intimidate another animal of
same species to determine dominance hierarchy.
Types of Learning
1. Habituation: Reduction in a previously displayed
response  habit. Ex: Horses stop reacting to traffic!
2. Conditioning: learned behavior in response to a
reward or punishment  training. Ex: Pavlov's Dog
3. Trial and Error: learning which involves practice.
4. Insight Learning: Learning from experience 
problem solving.
5. Imprinting: Animal forms a social attachment to
another object at a specific time. Ducks/Birds!!
Cell Theory
All living things are composed of cells.
Cells are the basic unit of life.
New cells come from old cells.
Levels of Cellar Organization
Cells Tissues Organs Organ System
1. Cells- basic unit of living things
2. Tissues- a group of similar cells that perform a
particular function.
3. Organs- groups of tissues that work together to
perform a task.
4. Organ System- a group of organs that work
together to perform a specific function.
Two types of cells
Prokaryotes
• Smaller and Simpler
• No Nucleus /
Nucleoid
• Bacteria
Eukaryotes
• Larger and Complex
• Contain more Organelles
• Nucleus
• Plants, Animals, Fungi,
and Protists
Plant and Animal Cells
• Plant cells have a cell
wall and chloroplast
• Animal cell do not
have a cell wall or
chloroplast.
Cell Organelles
•
•
•
•
•
•
•
•
Nucleus: Brain of cell (DNA)
Cytoplasm: Houses all the cells organelles
Ribosome: Protein Synthesis
Vacuole: Storage
Chloroplast: Site for Photosynthesis
Mitochondria: Site for aerobic respiration (ATP)
Cell Wall: Extra support & protection, cellulose.
Cell Membrane: allows some things in and
others out.
Cell Membrane/Plasma
Membrane
• Phospholipid bilayer (two layers of phospholipids)
– circular phosphates - hydrophillic (like water)
– fatty acid tails (lipids) - hydrophobic (don’t like water)
• Transport proteins allow movement of materials in
and out by active and passive transport.
• Cholesterol – keeps lipids from sticking
Homeostasis
•
Homeostasis- balance between internal
and external environment of cell.
Factors Affecting Homeostasis
1. Temperature
2. pH Level
3. Salt Concentrations
Types of Transport
• Passive
• Active
• Does not require ATP
• Requires ATP
• Move from high
concentration to low
concentration.
• Move from low
concentration to high
concentration.
• Osmosis (WATER)
• Diffusion (MOLECULES)
• Facilitated Diffusion
Cellular Movement (OSMOSIS)
•
WATER FOLLOWS THE SMALLER #!!
•
DISTILLED WATER IS ALWAYS 100%!
Steps to solve problems
1. If problem only contains water just follow the rule
that water follows the smaller #!
2. If solute is given subtract the number from 100 to get
the amount of water.
3. Once you have the amount of water for the inside
and out, follow step one.
What is an Enzyme?
•
Proteins that catalyze (speed) chemical
reactions within a cell.
•
LOCK AND KEY (Specific for substrate)
Factors affecting enzyme activity
1. pH
2. Temperature
Enzyme Activity
Cell Communication
Cells communicate to maintain Homeostasis!!
•
Hormonal Communication - chemical
message that travels through the bloodstream
to a target cell or target organ.
•
Neuron Communication - method that allows
organisms to detect and respond to stimuli.
PARTS OF A NEURON
1. Axon - sends message
2. Dendrite- receives message
Respiration
• Aerobic
• Anaerobic
• Requires Oxygen
• Mitochondria
• Provides Cell with
ATP
• No Oxygen Required
• Fermentation
• Bacteria
2 Types of Fermentation
Alcoholic: Alcohol / Yeast
Lactic acid: Muscle Soreness
EQUATION FOR
RESPIRATION
CARBON
DIOXIDE
GLUCOSE
C6H12O6 + 6O2
OXYGEN
ATP
6CO2 + 6H2O + ENERGY
WATER
Respiration in Humans = diffusion
in Lungs
Oxygen goes into the lung
Carbon Dioxide leaves the lung
CO2
O2
EQUATION FOR
PHOTOSYNTHESIS
WATER
6CO2 + 6H2O +ENERGY
CARBON
DIOXIDE
OXYGEN
C6H12O6 + 6O2
GLUCOSE
DNA
•
•
•
•
•
•
•
•
•
•
Deoxyribonucleic Acid
Double Helical Structure (Watson and Crick)
Deoxyribose Sugar
Determine Traits
Found in Nucleus
Hydrogen Bond holds bases together.
Covalent Bonds hold phosphates and sugars.
Bases: GCAT
G=C
A=T
Hydrogen Bond Holds bases!
Covalent Bond holds sugar and phosphate!
DNA Replication
•
USE BASES GCAT
•
TAKES PLACE IN THE NUCLEUS
Steps
1. DNA polymerase separates the original strand
of DNA. (unzips)
2. Replication begins on both strands of DNA
following the rules of base pairing.
RNA
• RNA is Ribonucleic Acid
• Ribose Sugar
• Single Stranded
• Bases: GCAU
• G=C
• A=U
• Protein Synthesis
Three types of RNA
Protein Synthesis
• Process whereby DNA encodes for the
production of amino acids and proteins.
• Process is divided into two parts:
» Transcription: Nucleus
» Translation: Ribosome
• 20 Amino Acids held by peptide bonds.
• 64 combinations for Codons
• Codons: 3 letter base sequence that codes for
one amino acid. EX: AUG
TRANSCRIPTION
• Nucleus
• Base U is used instead of T.
• mRNA is created.
TRANSLATION
• Ribosome
• Amino acids are brought to mRNA strand by
tRNA.
• Amino acids are held together by peptide
bondsprotein.
Mitosis
•
Results in Diploid (2n) cells = 46 chromosomes.
–
daughter cell is identical to parent cell
•
Interphase is the longest of the phase  DNA
replication and other preparation for cell division.
•
Body Cells (SOMATIC)
4 Stages: PMAT
1. Prophase
2. Metaphase
3. Anaphase
4. Telophase
5. Cytokinesis
Meiosis
•
•
•
•
•
Sperm in Males
Ova or Egg in Females
2 Cell Divisions
Haploid Cells (n=23)
Produces 4 total cells
– 4 sperm
– 1 egg & 3 smaller cells
Mitosis
Meiosis
1 division2 cells
2 divisions 4 cells
Daughter cells genetically
identical to parent cell & to
each other
Daughter cells are genetically
distinct from parent & each
other
Division is equilateral
2n2n
1st division reduction 2n n
2nd division equilateral n n
Sister chromatids migrate
Homologous chromosomes &
sister chromosomes migrate
Occurs in somatic/body cells
to reproduce body cells
Occurs in sex cells produces
gametes
Diploid diploid cells
Diploid haploid
No genetic variation
Crossing over causes variations
Gene Mutations
• Point Mutations- mutation that affects a
single nucleotide only at a specific point.
• Frame shift Mutations- mutation that shifts
the reading frame of the genetic message
by inserting or deleting a nucleotide.
Gene Chromosome Model
Body  Cells  Chromosomes  Genes DNA
Genes Provide Organisms with:
1. Looks
2. Some illnesses
3. Body Structure
What is Genetic Engineering?
• Method of inserting foreign DNA into a host
organism of the same or different species!!
• Known as Recombinant DNA Technology!!
• Recombinant DNA is foreign DNA!
Genetic Engineering
• Process of making changes in the DNA code of
living organisms.
• Gel Electrophoresis- a procedure used to
separate and DNA fragments into bands.
• Cloning- copying an organisms DNA to make
an exact copy of the same organism.
DNA Fingerprinting
 Identifies crime suspects
Identifies
paternity 
Mendel’s Work
• Study of Heredity (Gregor Mendel= Pea Plants)
• Genes – chemical factors that determine traits
• Alleles – different forms of genes
• Traits – a specific characteristic, such as color or plant height,
that varies form one individual to another
– Dominant traits always show up in an offspring (capital letter)
– Recessive traits are masked by a dominant gene (lower case letter)
• Hybrids – The offspring of crosses between parents with
different traits
Genetics
• Principle of Dominance: some alleles are dominant and others
are recessive.
• Principle of Independent of Assortment- genes for different
traits can segregate independently during the formation of
gametes.
• Incomplete dominance- situation in which one allele is not
completely dominant over another. WHITE and RED = PINK
• Codominance- situation in which both alleles of a gene
contribute to the phenotype of the organism.
BLACK and BLUE= BLACK & BLUE
• Multiple Alleles = having three or more traits for the same gene.
Multiple Alleles / Blood Type
• NOTE: O blood type is recessive.
– O= little i
– Blood Types: A, B, AB, & O
• OO = blood type O
AO = blood type A
BO = blood type B
AB = blood type AB
AA = blood type A
BB = blood type B
Genetics
• Homozygous (PURE)= TT or tt (SAME)
• Heterozygous (HYBRID)= Tt (Different)
• Phenotype= Physical characteristics
• Genotype= genetic makeup using alleles
(Letters)
• Sex-linked Traits= genes found only on the X
chromosome and not on the Y chromosome.
– Males= XY
– Females= XX
Monohybrid Cross
Heterozygous
tall parent
T
t
T
T
T
t
TT
Tt
Tt
tt
t
Heterozygous
tall parent
Test Cross
T
 Always use
homozygous recessive
 If all offspring have
the dominant trait then
the genotype is
probably pure (TT x tt)
 If some of the
offspring show the
recessive trait, then
the genotype is
heterozygous.(Tt x tt)
t
t
Tt
Tt
T
Tt
Tt
T
t
t
Tt
tt
t
Tt
tt
Dihybrid Cross
RrYy x RrYy
RY
Ry
rY
ry
RY
RRYY
RRYy
RrYY
RrYy
Ry
RRYy
RRyy
RrYy
Rryy
rY
RrYY
RrYy
rrYY
rrYy
ry
RrYy
Rryy
rrYy
rryy
Patterns of Inheritance
Karyotype- set of photographs of chromosomes grouped in order in pairs.
Human Karyotype= 46 chromosomes (23 pairs)
44 chromosomes= Autosomal Chromosomes
2 chromosomes= Sex Chromosomes
TOTAL= 46
• Results from having an extra chromosome!
• Pedigrees- Chart that shows the hereditary
relationships within family a family.
Evolution
• CHANGE OVER TIME (Charles Darwin)
• Found similarities with finches and tortoises
• Fossils- preserved remains of ancient
organisms.
Stanley Miller’s Experiment
Re-created early Earth’s atmosphere and found
that simple organic molecules such as amino
acids were present.
Evidence of Evolution
• The fossil record!
• Geographical Distribution of living Species!
• Homologous Body Structures- structures that have
different mature forms but develop from the same
embryonic tissues.
• Vestigial Structures- structures that serve no useful
function in an organism.
• Similarities in Embryology!!
Principles of Evolution
• Adaptation - any inherited trait that increases
and organisms chance of survival.
• Common Descent - all living and extinct species
were derived from a common ancestor.
• Humans and Chimpanzees have the closest
evolutionary (DNA) similarity!!
Principles of Evolution
• Natural Selection - Naturally in the environment
(Also known as Survival of the Fittest)
• Only the strongest/Fittest species survives
to pass on its traits to offspring.
Charles Darwin’s Theory of Evolution
1. Overproduction
•
Species produces more offspring than survive.
2. Competition
–
Organisms compete for limited resources
3. Survival of the Fittest
•
Only the strongest survive and pass on their traits to their
offspring.
4. Variations
–
–
–
differences among organisms that help organism survive
occur among members of the same species
Result from sexual reproduction, mutations, meiosis
4 Factors that change a gene pool
1. Natural Selection: only the strongest survives and
passes on genes.
2. Mutations: adds new genes to the pool to be passed
on to offspring.
3. Migration: movement into and out of population.
•
•
INTO= Adding genes
OUT= Removing genes
4. Isolation: Often causes speciation.
Geographic isolation
•
Barrier between population divides it / Habitat
Fragmentation
•
Speciation= development of a new species.
Reproductive isolation
• Organisms can no longer mate / caused by
geographical isolation
Classification
•
Taxonomy- discipline of classifying organisms and
assigning each organism a universally accepted
name. (Carolus Linnaeus)
•
Binomial nomenclature- System in which each
species is assigned a two part scientific name.
•
Genus (Capitalized) Species (Lowercase)
Levels of Organization (general to most specific)
1.
2.
3.
4.
5.
6.
7.
Kingdom
Phylum
Class
Order
Family
Genus
Species
Dichotomous Key Example
Kingdoms
Kingdom Cells
Feeding
Example
Monera
prokaryotes Heterotroph
bacteria
Fungi
eukaryotes Heterotroph
Protista
Plant
eukaryotes Autotroph
Heterotroph
eukaryotes Autotroph
mushroom,
mold, yeast
amoeba,
paramecium
Animal
eukaryotes Heterotroph
angiosperm,
gymnosperm
annelid,
arthropod,
amphibian,
mammal
Plants
• Gymnosperms
• Angiosperms
• Reproduction by seeds
• Seed inside of Cone
• Needle shaped Leaves
• Flowering Plants
• Seeds inside of Ovary
Example: Fruit
Plant Parts
• Root System - provides plant with water
and nutrients, anchors the plant.
• Stem System - support and transport of
nutrients.
• Leaf System - absorb light, gas exchange,
and transpiration.
Plant Tropisms
• Tropisms – growth of a plant in response to
stimuli. This is an innate behavior!!
• Positive Tropisms - Plant grows toward the
stimulus.
• Negative Tropisms- Plant grows away from the
stimulus.
Plant Tropisms
• Phototropism- response to light.
• Geotropism - response to gravity.
• Thigmotropism- response to touching.
Leaf Structure and Functions
•
•
•
•
•
Cuticle: Waxy Layer, Protection
Epidermis: Skin, Protection
Palisade: photosynthesis
Spongy: Gas exchange
Vascular Bundle: Transport
– Xylem: Water/Minerals up
– Phloem: Sugars down
• Stomata: Opening where gas
exchange occurs and
transpiration.
• Guard Cells: Regulate the
opening and closing of the
stomata.
Viruses
• Not classified in a kingdoms
• Nonliving
• Piece of nucleic acid covered by protein coat
(capsid).
Capsid
Nucleic acid
Tail
Immunity to Disease
• Passive immunity – medicines
• Acquired immunity – B & T cells (made by
body)
• B-cells – make antibodies
• T-cells – 2 types:
– helpers (help B-cells make antibodies)
– killers (destroy invaders)
Internal & External Factors
• Viruses (infections) – HIV, Influenza,
smallpox
• Bacteria (infections) – streptococcus (strept
throat)
• Parasites (mosquitoes – carry viruses)
• Toxins – lead poisoning (bioaccumulation in
the food chain)
Health Factors…
• Tobacco use may cause lung and/or mouth
cancer
• Exposure to the sun may increase your chance
of skin cancer (negative), provides Vitamin D
(positive) and Folic Acid (positive)
• Diabetes may be controlled with diet and
exercise, but genetics are a major factor
• PKU diets consist of fruits, vegetables, and
proteins low in phenylalanine
• Genetic disorders (down syndrome – trisomy 21)
Malaria
• Vector
(transmitted by)
Plasmodium
parasite
• Sickle cell
anemia makes a
person resistant
to malaria