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