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Science OGT Study Guide
Science & Technology, Scientific Inquiry, Scientific Ways of Knowing
Science & Technology
Science- asking questions and seeking answers
in order to gain a better understanding of the
natural world.
Technology- using science to develop
new products.
Technology can have advantages &
disadvantages
Ex. Advantage: Cars allow us to travel and get
from place to place quickly.
Disadvantage: Cars release pollution and are
contributing to global warming.
ex. Hybrid cars- scientists using technology to
help reduce the amount of pollution released.
Scientific Knowledge
Scientific Knowledge: helps to solve problems and
make life easier.
• Important that scientific knowledge is
reviewed by other scientists
• Scientists always build on other scientists
work!
o Helps eliminate BIAS
Bias- unfair prejudice towards a particular opinion/
your personal point of view
Ex. The Ohio State Buckeyes are the best football
team in the nation because it is your hometown team.
Ethics
Ethics- a set of principles that guide decision-
making.
• What you feel is RIGHT or WRONG
Ex. Would it be ethical for researchers to test a
drug on you without telling you the side effects?
No- unethical
Ex. A coyote living in the wild has rabies. Would
it be ethical to kill it?
Side 1- unethical- it has not harmed any humans
yet
Side 2- ethical- it could come into contact with
humans and we must take every measure to
prevent harm and protect ourselves.
Science Ethical Questions
Examples- Stem cell research, cloning
Stem cell research has a great potential to help
cure many diseases, but many oppose because
using stem cells from embryos results in death of
the embryos.
Scientific Inquiry Scientific Method
1. Make an OBSERVATION
2. Ask a QUESTION
3. RESEARCH 4. Form a HYPOTHESIS – your educated guess to
answering the question.
5. EXPERIMENT – prove or disprove the hypothesis
• Must only examine one variable at a time! Try
to control all other conditions!
CONTROL GROUP- sample that is not treated
EXPERIMENTAL GROUP- sample that is treated
• Compare the two groups to see if the
hypothesis is correct!
DEPENDENT VARIABLE- What you MEASURE
INDEPENDENT VARIABLE- What you CHANGE
6. ANALYZE DATA
• Observations and measurements
• Put data in table or graph to analyze results
7. CONCLUSION
• Was the hypothesis right or wrong based on the
data
* Communicate results
* After repeated testing and same results - can formulate a
THEORY – detailed explanation of large bodies of
information that withstands repeated testing.
Example: You want to test fertilizer to see if it affects the
growth of tomatoes
Control- NO fertilizer
Independent variable- fertilizer
Dependent variable- Growth
Science OGT Study Guide
Life Science
Cell Organelles
Organelle Function Nucleus Control center of cell &
contains DNA
Ribosome Makes proteins
Mitochondria Site of cellular respiration-
breakdown food to create
energy
Endoplasmic Reticulum Transports materials
throughout cell
Golgi apparatus Processes & packages
proteins for shipment out of
cell
Vacuole Stores water, food & waste
Cytoplasm Cell fluid that surrounds the
organelles
Cilia/Flagella Assist in movement
Lysosomes Breakdown of food,
bacteria, old organelles
Plasma Membrane Allows certain materials to
enter or leave cell
Differences between Plants &
Animal Cells
Plant Cells Have:
• Chloroplasts- contain
chlorophyll; site of
photosynthesis
• Cell Wall- gives plant cell
support
Cellular Processes
Photosynthesis: process where plants take in water, carbon dioxide, and use light energy to make glucose
(food).
6CO2 + 6H2O + ENERGY � C6H12O6 + 6O2
carbon + water + energy glucose + oxygen
dioxide from sun � FOOD
O2
H20 Food
CO2
Takes place in
the
Chloroplasts!
Examples of
Eukaryotic
Cells
Cells
Prokaryotes: no nucleus
example: bacteria
Eukaryotes: have nucleus &
membrane-bound organelles
example: plants, animals, protists, &
fungi
Cellular Processes
Respiration: breaking down food to release energy.
C6H12O6 + 6O2 � 6CO2 + 6H2O + ENERGY
glucose + oxygen � carbon + water + ENERGY
food dioxide
oxygen carbon dioxide
• End products of photosynthesis are the starting reactants for respiration & vice versa!
Takes place in
the
Mitochondria!
Genetics
Genes come in pairs of chromosomes (half
from mom & half from dad)
Alleles: the different form of a gene
(ex. tall, short)
-can be dominant or recessive
dominant: will be expressed if any other
alleles are present
• CAPITAL LETTER (T)
recessive: won’t be expressed when a
dominant allele is present
• lowercase letter (t)
Homozygous: 2 of the same allele
ex. TT or tt
Heterozygous: one dominant and one
recessive allele
ex. Tt
Genotype: the genetic make-up of an
individual- letters!
ex. TT, Tt, tt
Phenotype: physical appearance (how they
look)
ex. Tall or short
Punnett Squares
Punnett squares: express the possible combinations
for a certain trait an offspring may inherit from the
parents.
Example:
In pea plants, the trait for height has two alleles- tall
or short. Tall is dominant over short.
Cross a heterozygous tall pea plant with a short.
Heterozygous tall: Tt
Short: tt
T t
t Tt tt
t Tt tt
Probability of offspring:
Genotypes:
Tt = 2 out of 4 or 50%
tt = 2 out of 4 or 50%
Phenotypes:
Tall (TT or Tt) = 50%
short (tt) = 50%
Biotic & Abiotic Factors
Abiotic: not living
ex. rock, water, sunlight
Biotic- living
ex. tree, dog, bacteria
DNA
Deoxyribonucleic acid
genetic material that is passed down from parents to offspring
• shape is a double helix
Pedigree
Shows the inheritance
of a particular allele,
usually an allele for a
disease throughout
generations of a
family.
Carrier: someone who
does NOT have the trait,
but carries the allele &
could pass it on to their
offspring.
Energy Flow
Producers- make their own food. (Autotrophs) Examples: plants & algae
Consumers- depend on other organisms for their food (Heterotrophs)
• Herbivore- eat only plants
• Omnivore- eat both plants & animals
• Carnivore- eat only other animals
• Saprophyte- organisms that obtain food from dead organisms or waste products from living
organisms (decomposers)
Community Interactions
Competition: occurs when organisms compete for a resource.
Predation: organisms (predator) that kill and eat other organisms (prey)
Symbiosis: relationship where one organism is living on or inside another.
Mutualism: a symbiosis where both organisms benefit
ex. Flower & Bee- Bee pollinates flower; the flower provides bee with nectar
Commensalism: a symbiosis where one organism benefits & the other is unaffected
ex. A bird living in a tree- the tree gives bird protection; the tree is not helped or harmed.
Parasitism: a symbiosis where one organism benefits & the other is harmed
ex. Flea and dog- The flea benefits by biting the dog to get the blood as food; the dog is harmed by the flea
���� gives energy to
Example:
Tree � Deer
Tree gives energy to the Deer
Food Web
Examples of Human Impact on Environment
• Pollution
• Global Warming
• Cutting down forests
• Growth & land exploitation
• Introduction of chemicals into the environment (examples: pesticides like DDT).
Natural Selection
Natural Selection: favorable traits are better able to successfully reproduce than organisms that lack these
traits.
• Survival of the fittest
• Driven by competition among individuals for resources necessary for survival
• One that survives can pass on those traits to future generations
Example:
Millions of years ago, some giraffes were born with short necks & others were born with long necks.
When low grass and plants (food) became scarce, the giraffes with long necks were able to reach the
leaves in high trees and survive. The short-neck giraffes could not reach the food, so they did not survive.
Only the long-neck giraffes were able to pass their long-neck gene to future generations. Nature favored
the long-neck trait.
Science OGT Study Guide
Physical Science
Atoms
Protons= positive charge, found inside
nucleus
Electrons= negative charge, found
outside of nucleus
Neutrons= neutral or NO charge,
found inside nucleus
In a neutral atom, the # of protons = #
of electrons
Ex. Carbon has 6 positive protons and
6 negative electrons so,
+ 6 – 6 = 0 NO CHARGE!
Periodic Table
Periodic Table
� Atomic # (#of protons)
� Atomic Symbol
� Atomic Mass = # of protons + # of neutrons
The group number (found at the top of each column) is
equal to the number of valence electrons.
This is used when drawing Lewis Dot Structures.
Ex.
X would be found in column VA because it
has 5 valence electrons.
6
C
Carbon
12.010
Reactions
Ionic Bonds- form when valence electrons
are transferred from one atom to another,
creating positive and negative ions.
Na + Cl � Na + Cl � Na+ + Cl
-
Na lost 1 negative electron, so now it is
positive. Cl gained 1 negative electron, so
now it is negative.
Covalent Bonds- form when sharing valence
electrons.
Cl + Cl � Cl Cl
Now both Cl atoms have 8 valence electrons
because they are sharing a pair of electrons.
Chemical Reactions can be shown with a
balanced chemical equation.
2H2 + O2 � 2H2O
H= 4 H= 4
O= 2 O= 2
The same # of atoms must be the same on the
reactant and product side of the equation.
Group 18 are the Noble Gases.
They are not likely to combine with other elements
because they have a full outer shell.
Properties of Matter Physical Property- determined without changing identity
of the substance.
Ex. Color, density, phase (solid, liquid, gas), odor, boiling
point, melting point
Density = mass/ volume
Substances that are MORE dense SINK
Substances that are LESS dense FLOAT
Chemical Property-displays when a substance changes
into a new substance.
Ex. Burning, corrosion
Chemical Chemical Reactions
Some reactions give off heat and some require heat to
react.
Endothermic- a reaction that absorbs heat from the
surroundings.
Ex. Baking a cake- needed heat from the oven
to bake.
Ex. Melting an ice cube
Exothermic- a reaction that gives off heat.
Ex. Burning wood
Heat Transfer
Heat energy always travels from HOT to COLD
Conduction- direct contact
ex. The heat from the burner transfers
heat directly to the pot.
Convection- heat rises; cool sinks/ liquid or gas
Radiation- by electromagnetic waves
ex. Heat from the sun
Newton’s Laws of Motion
1st Law- (INERTIA) an object in motion stays in motion and an object at rest stays at rest unless acted on
by an outside force.
Ex. Football will remain at rest on the field until someone kicks it.
The football will then stay in motion until gravity and friction stop it.
Friction- slows down an object Ex. Air resistance
Gravity- under ideal conditions, objects fall to the ground at the same rate- the mass does not matter.
2nd
Law- F = ma Force = mass x acceleration
• a force causes an object to accelerate
Ex. Bowling � the mass of the bowling ball multiplied by how fast the ball is rolling
determines how great the force is that hits the pins.
Which would provide a greater force- A truck traveling at 55 mph or a small car traveling at 55 mph?
or The truck- because it has more mass!
3rd
Law (ACTION/ REACTION)- for every action, there is an equal and opposite reaction.
• Ex. When a baseball bat hits a baseball (ACTION)
o The OPPOSITE REACTION force would be the baseball hits back on the bat with an EQUAL
amount of force
Energy
Potential vs. Kinetic Energy
Potential – Stored energy
Kinetic- Energy in motion
Law of Conservation of energy- energy
cannot be created or destroyed- only
CHANGED.
Energy Conversions
Ex. Light a match
Potential chemical � converted into heat
Energy and light energy
Waves
Waves- (ex. Sound, seismic, water, and light)
have energy and waves can transfer energy
when they interact with matter.
Wavelength crest
Amplitude
trough
Frequency- the # of waves that pass a point in
a given amount of time
Low frequency-
High frequency-
Notes:
Science OGT Study Guide
Earth & Space Science
Big Bang Theory
Theory that the earth was created in one
giant explosion billions of years ago, and is
constantly expanding today from this
location.
Evidence of the Big Bang Theory – red shift
Red shift: displacement of a star’s light
toward the red end of the spectrum, caused
by an increase in distance from the star and
the observer.
*The light most galaxies give off is close to
the red end of the spectrum because as they
move farther out, the energy becomes weaker
and stretched out. This light energy is
longer and the color is RED.
How a star is formed
Nebula: a cloud of dust and gas that are
pulled together by gravity.
The gravity produces great heat, when hot
enough, nuclear fusion occurs which
causes hydrogen protons to join together
producing the massive energy just as our
sun does.
Earth’s position in the Solar System
Geocentric Theory: earth is the center of the
solar system- WRONG
Heliocentric Theory: Copernicus proposed
that the sun is the center of the system.
CORRECT! Earth & other planets orbit the
sun.
Law of Universal Gravitation
-Between any two objects there is an attraction
(gravity) that is proportional to the mass of the
objects and the distances between them.
-Our sun is more massive than the planets so
they revolve around the sun.
-Earth is more massive than the moon, so the
moon revolves around the earth.
-Less massive objects still provide a pull
(force) on more massive objects.
-The moon has strong enough gravity to pull
on water from the oceans- this is why we have
tides: twice daily rise and fall in the water
level of Earth’s oceans.
History of Earth
• Began with a nebula
• Early earth had lots of volcanoes
o gas from volcanoes made first atmosphere
• cyanobacteria- first life on earth
o Lived in oceans, performed photosynthesis and released oxygen which helped put
oxygen into the atmosphere.
Learn about the history of Earth by studying rocks and fossils.
• Fossils can be used to match up rock layers that are far apart.
• Matching rock layers
Geologic Time Scales
Relative Time Scale: determine age by the sequences of rocks.
Ex. oldest rock would be found on bottom, youngest rock on top.
Absolute Dating: actual dates and ages
Ex. Radiometric dating
• Some rocks contain elements with unstable isotopes that decay slowly over time. They will
decay into a different element that is stable. This change occurs at a rate called a half life-
amount of time required for half a sample of the radioactive isotope to decay.
o Can use this to determine the age of the Earth.
Plate Tectonics
Convection Currents
Mantle
Core
Crust
Diagram of the Earth
Effects of Plate Tectonics: plates move & interact to
produce different results.
• Alfred Wegener proposed the theory of
Continental Drift – continents are drifting across
Earth’s surface.
o based on how the continents fit together like pieces of a puzzle.
o Evidence: Matching fossils found on different continents.
• Sea-floor spreading: new ocean crust is created at mid-ocean ridges as older crust moves away.
Mid-ocean ridge: underwater mountains that extend into all oceans.
• Subduction Zone: when an ocean plate collides with a continental plate, the ocean plate tends to
slide under the continental plate & forms a subduction zone.
• Mountain Ranges: occurs when Earth’s plates collide and push up.
• Earthquakes: when one plate slides past another
• Volcanoes & islands: hole in crust, magma rising up from earth’s interior to the surface
o Example: Hawaiian Islands
• Folding & Faulting: movement of plates can cause rocks to bend, fracture, and slide.
Plate tectonics: theory that Earth’s crust is
broken up into a number of large plates
that move & interact.
Convection Currents: transfer of heat by
the flowing action within a liquid or gas-
heat rises, cool sinks. (Moves the plates)
Mantle: Thick layer of rock below
Earth’s crust; it is solid, but flows very
slowly
Core: Earth’s center
Crust: Outermost solid rock layer
Example: Glacial deposits would be the
youngest rock and Granite would be
the oldest rock
Earth’s Resources
Renewable Nonrenewable
-can be replaced quickly -cannot be replaced quickly
-Examples: sunlight, water, wind, -Examples: fossil fuels- oil, coal, gas &
crops, & trees minerals
• Fossil Fuels- oil, coal, & natural gas
o form from fossils millions of years ago.
� Burning of fossil fuels can cause global warming.
Global Warming
Global Warming: increase in worldwide
temperature.
• The Earth needs a process called the
greenhouse effect to keep it from
freezing.
The Earth has an insulation layer of CO2 in
the atmosphere to help keep the warmth. It
allows some heat to escape, so it does not get
too hot. When we burn fossil fuels, we
release CO2 into the atmosphere and the heat
cannot escape. This is causing an increase
in temperature for the Earth.
Effects of Global Warming
• ice caps melting- raise in sea level
• weather changes
Protecting Earth’s Resources
What can we do to protect Earth’s Resources?
• Conservation- protecting Earth’s resources
Examples on how to Conserve:
1. REDUCE
• reduce amount of driving-ride bike, carpool
• turn off water & electricity when not in use
2. REUSE
• Donate old clothing so others can reuse
• Reuse plastic bags
3. RECYCLE
• Recycle cans, newspaper, glass, etc.
Alternative Energy Sources
Instead of burning fossil fuels that release CO2 into the
atmosphere, there are other energy sources that we can use!
Energy Benefit Disadvantage
Solar Produces no CO2 Expensive
Wind Produces no CO2 Need wind
Hydroelectric (water) Produces no CO2 Need large river
Geothermal Produces no CO2 Need access to
underground
temperature
Nuclear Produces no CO2 Produces
radioactive waste
Biomass
(composting/burning)
Reduces landfill
space
Pollutes air &
produces CO2
Ozone Layer
• Ozone layer: layer that shields Earth
from harmful UV light.
• Chemicals called chlorofluorocarbons
(CFCs) damage the ozone layer.
CFCs can be found in refrigerators, air
conditioners, & aerosol cans.
o These substances react &
destroy the ozone layer
o The chemicals have been
banned in the U.S.
Biomes
Biome: very large region with its own characteristic groups of plants & animals, and climate
(how much rainfall and temperature).
• Biomes with colder temperatures have less amount of life living there.
o Low Biodiversity
• More heat & precipitation means more plants & more life
o High Biodiversity
6 Major Biomes
• Tundra- N & S Poles
o Cold
o Low biodiversity
• Coniferous Forest
o Cool summers & cold winters
o Trees are coniferous (pine cones)
• Deciduous Forest- State of Ohio
o Warm summer & cold winters
o Trees are deciduous- loose their leaves
• Grasslands
o Dry & wet seasons
• Tropical Rainforest
o Abundant rainfall
o High temperatures
o Great biodiversity of plants & animals
• Desert
o Little rain
o Extreme temperature fluctuations (cold at night & hot in the day)
o Low biodiversity
Weather
• Sun is a main cause of weather
o Heats air & land
o Different surfaces on Earth will heat up at different rates causing hot air to rise
& cool air to sink� causes wind
• Air pressure reflects temperature
o Cold air sinks � producing high air pressure
o Warm air rises� producing low air pressure
o Wind patterns are produced by air flowing from a region of high air pressure to
low air pressure
• Weather patterns related to geography include: tornadoes, tropical hurricanes, lake
effect snow, monsoons, & El Nino