Science OGT Study Guide Science & Technology, Scientific Inquiry, Scientific Ways of Knowing

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1 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. Ethics Ethics- a set of principles that guide decisionmaking. 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 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. 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

2 Cells Prokaryotes: no nucleus example: bacteria Eukaryotes: have nucleus & membrane-bound organelles example: plants, animals, protists, & fungi Differences between Plants & Animal Cells Plant Cells Have: Chloroplasts- contain chlorophyll; site of photosynthesis Cell Wall- gives plant cell support Science OGT Study Guide Life Science Nucleus Ribosome Mitochondria Cell Organelles Organelle Function Endoplasmic Reticulum Golgi apparatus Vacuole Cytoplasm Cilia/Flagella Lysosomes Plasma Membrane Control center of cell & contains DNA Makes proteins Site of cellular respirationbreakdown food to create energy Transports materials throughout cell Processes & packages proteins for shipment out of cell Stores water, food & waste Cell fluid that surrounds the organelles Assist in movement Breakdown of food, bacteria, old organelles Allows certain materials to enter or leave cell Examples of Eukaryotic Cells Cellular Processes Photosynthesis: process where plants take in water, carbon dioxide, and use light energy to make glucose (food). 6CO 2 + 6H 2 O + ENERGY C 6 H 12 O 6 + 6O 2 carbon + water + energy glucose + oxygen dioxide from sun FOOD Takes place in the Chloroplasts! H 2 0 CO 2 O 2 Food

3 Cellular Processes Respiration: breaking down food to release energy. C 6 H 12 O 6 + 6O 2 6CO 2 + 6H 2 O + ENERGY glucose + oxygen carbon + water + ENERGY food dioxide Takes place in the Mitochondria! oxygen carbon dioxide End products of photosynthesis are the starting reactants for respiration & vice versa! 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 Biotic & Abiotic Factors Abiotic: not living ex. rock, water, sunlight Biotic- living ex. tree, dog, bacteria 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% DNA Deoxyribonucleic acid genetic material that is passed down from parents to offspring shape is a double helix

4 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. 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 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)

5 Food Web gives energy to Example: Tree Deer Tree gives energy to the Deer 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. 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).

6 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, = 0 NO CHARGE! 6 C Carbon 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. Periodic Table 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 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 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. 2H 2 + O 2 2H 2 O 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.

7 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. 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. Burning wood ex. Heat from the sun Newton s Laws of Motion 1 st 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. 2 nd 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! 3 rd 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

8 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 Amplitude trough crest Frequency- the # of waves that pass a point in a given amount of time Low frequency- High frequency- Notes:

9 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. 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. 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. 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

10 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. Example: Glacial deposits would be the youngest rock and Granite would be the oldest rock 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 lifeamount of time required for half a sample of the radioactive isotope to decay. o Can use this to determine the age of the Earth. Diagram of the Earth Plate Tectonics Convection Currents Mantle Core Crust 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. 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 gasheat 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 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.

11 Renewable -can be replaced quickly -Examples: sunlight, water, wind, crops, & trees Earth s Resources Nonrenewable -cannot be replaced quickly -Examples: fossil fuels- oil, coal, gas & 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 CO 2 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 CO 2 into the atmosphere and the heat cannot escape. This is causing an increase in temperature for the Earth. 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. Effects of Global Warming ice caps melting- raise in sea level weather changes 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. Alternative Energy Sources Instead of burning fossil fuels that release CO 2 into the atmosphere, there are other energy sources that we can use! Energy Benefit Disadvantage Solar Produces no CO 2 Expensive Wind Produces no CO 2 Need wind Hydroelectric (water) Produces no CO 2 Need large river Geothermal Produces no CO 2 Need access to underground temperature Nuclear Produces no CO 2 Produces Biomass (composting/burning) Reduces landfill space radioactive waste Pollutes air & produces CO 2

12 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