8th grade Science STAAR Review Objective 1: Matter & Energy

Transcription

1 8.5.A describe the structure of atoms, including the masses, electrical charges, and locations, of protons and neutrons in the nucleus and electrons in the electron cloud 8th grade Science STAAR Review Objective 1: Matter & Energy Atomic Particles An atom is made up of 3 subatomic particles. Subatomic Particles Proton Neutron 1 Approximate Atomic Mass (amu) Electrical Charge Location in Atom 1 Positive (+) Nucleus No Charge (0) Nucleus Electron 0 Negative (-) Electron Cloud 8.5.B identify that protons determine an element s identity and valence electrons determine its chemical properties, including reactivity Atomic Structure Protons= determine an element s identity; So this element s identity is Boron. The electrons in the last shell or energy level of an atom. Valence electrons determine reactivity of an atom. Valence Electrons= determine an element s chemical properties, including reactivity (how elements combine or break down into new products)

2 8.5.C interpret the arrangement of the Periodic Table, including groups and periods, to explain how properties are used to classify elements Periodic Table 8.5.D recognize that chemical formulas are used to identify substances and determine the number of atoms of each element in chemical formulas containing subscripts Rows on the Periodic Table are called Periods Columns on the Periodic Table are called Groups or Families Elements in the same Group/Family have similar properties because they have the same number of valence electrons! Chemical Formulas Chemical Formulas represent compounds as chemical symbols represent elements. Example: Water is a compound (2 or more elements chemically bonded.) Water s chemical formula is H 2 O. Example: Helium is an element. Helium s chemical symbol is He. Counting Atoms The subscript (little #) identifies how many atoms of that element are in each molecule If there is no subscript, there is just 1 atom of the element Subscripts get multiplied by the coefficient (big #) Example: 2Na 2 CO 3 a) number of sodium (Na) atoms = 2 x 2 = 4 b) number of carbon (C) atoms = 2 x 1 = 2 number of oxygen (O) atoms = 2 x 3 = 6

3 8.5.E investigate how evidence of chemical reactions indicate that new substances with different properties are formed Chemical Reaction A Chemical Reaction occurs when elements rearrange to form new substances. Example: 8.5.F recognize whether a chemical equation containing coefficients is balanced or not and how that relates to the law of conservation of mass It s made of the same ingredients, but has changed into another substance. Chemical Equation When a chemical reaction occurs, it can be described by an equation. This shows the chemicals that react (called the reactants) on the left-hand side, and the chemicals that they produce (called the products) on the right-hand side. Example REACTANTS PRODUCT Fe + S FeS So in the above equation, the reactants are Fe and S. The product is FeS. Law of Conservation of Mass The Law: Matter cannot be created or destroyed. What does this mean?? The mass of the reactants MUST EQUAL the mass of the products! Whatever atoms you start with, you have to have after the reaction. This is why equations must be balanced! Balanced Equation Reactants Si = 1 atom O = 2 atoms Products Si = 1 atom O = 2 atoms Balancing game: Are the following equations balanced or unbalanced? 1. Si + O 2 SiO H 2 0 H 2 + O Al + 3Cl 2 2AlCl 3

4 7.5.C diagram the flow of energy through living systems, including food chains, food webs, and energy pyramids Shows the flow of energy. All energy comes from the SUN! Food Chain Note: The sun provides energy to plants to produce food in the process called Photosynthesis The sun s energy is radiant energy! Food Web Shows all the possible feeding relationships between organisms living in an ecosystem. Arrows show the flow of energy points to the predator! Energy Pyramid Most of the energy is stored in the producers! Question/ Checkpoint: In the energy pyramid above, show the flow of energy using arrows.

5 7.6.A identify that organic compounds contain carbon and other elements such as hydrogen, oxygen, phosphorus, nitrogen, or sulfur Organic Compound MUST contain carbon and at least two hydrogen atoms. Can also contain O, P, S, F or N. 7.6.B distinguish between physical and chemical changes in matter in the digestive system C 12 H 22 O 11 Sugar Physical Change As food travels through the digestive system, it undergoes a series of Physical and Chemical changes that break it down to provide energy for cells. Physical Changes simply alter the appearance of something. For example, chewing breaks large food molecules into smaller ones. Chemical Change Chemical Changes occur when the chemical make-up of the food particle is changed to create a new substance. During the digestive process, enzymes change carbohydrates, proteins, fats and nucleic acids into substances that can be absorbed by cells called Chyme. 6.5.C differentiate between elements and compounds on the most basic level Elements An Element is a substance that contains only one kind of atom. Elements Compounds A compound is a substance that contains at least two different elements chemically bonded. Examples: Copper (Cu); Sodium (Na) Examples: NaCl, H 2 O, CaCO 3

6 6.6.A compare metals, nonmetals, and metalloids using physical properties such as luster, conductivity, or malleability 6.6.B calculate density to identify an unknown substance Physical Properties Metals Nonmetals Metalloids 1. Luster(shiny) Shiny/has luster dull Can be shiny or dull 2. Conductivity(conducts YES NO Maybe electricity) 3. Malleability (hammered into sheets) ex. Al foil Calculate Density YES NO Some Formula chart! Length = 8 cm Width = 2 cm Rock Mass = 27g Rock Volume = 10ml Height = 4 cm Mass = 352 g 352 g = 352 g = 5.5g/cm 3 64cm 3 Volume; 8cm x 2cm x 4cm = 64 cm 3 27g = 2.7 g/ml 10ml Volume: 10 ml Look at the table below to answer the following question: What is the rock in the example made of? Explain. Substance Density (g/ml or g/cm 3 ) Gold 19.3 Lead 11.3 Copper 8.9 Aluminum 2.7 Ethyl alcohol.92

7 8.6.A demonstrate and calculate how unbalanced forces change the speed or direction of an object s motion 8th grade Science STAAR Review Objective 2: Force, Motion, & Energy Force A Force is a Push or a Pull that can change motion. How Force is Measured Newton - The SI unit used to measure force. The symbol for Newton is N. Formula chart! Net force= 3N to the right Net Force= mass x acceleration F = m x a I am a roller skater with a mass of 72kg. If I am accelerating toward a wall at 3.7m/s 2, what will be the amount of force at which I hit the wall? Spring Scale Measures Force in Newtons (N). Net Force When more than one force acts on an object, the forces combine to form a Net Force. The combination of all the forces acting on an object is the Net Force. Net Force = 2 ADD forces in the same direction Magnitude is the size of a force. Net Force = 1 SUBTRACT forces in opposite directions.

8 8.6.C investigate and describe applications of Newton s law of inertia, law of force and acceleration, and law of action- reaction such as in vehicle restraints, sports activities, amusement park rides, Earth s tectonic activities, and rocket launches Newton s 1 st Law Newton s First Law: An object at rest will remain at rest unless acted on by an unbalanced force. An object in motion continues in motion with the same speed and in the same direction unless acted upon by an unbalanced force. This law is often called the Law of Inertia Examples of Newton s 1st Law: Car suddenly stops and you strain against the seat belt (vehicle restraints) because our bodies want to keep moving When riding a horse, the horse suddenly stops and you fly over its head Ketchup stays in the bottom (at rest) until you bang (outside force) on the end of the bottom Can you think of another example? Newton s 2 nd Law Newton s Second Law: Acceleration is produced when a force acts on a mass. The greater the mass (of the object being accelerated) the greater the amount of force needed (to accelerate the object). It can be measured by F = M x A This law is often called the Law of Acceleration Calculate F = 1000 kg x 0.5 m/s/s F = 500 N Examples of Newton s 2nd Law: Hitting a baseball- the harder the hit, the faster the ball goes accelerating A grocery cart filled with lots of food vs. an empty grocery cart The positioning of football players massive players on the line with lighter (faster to accelerate) players in the backfield Can you think of another example?

9 Newton s 3 rd Law Newton s Third Law: For every action there is an equal and opposite re-action. For every force there is a reaction force that is equal in size, but opposite in direction. This law is often called the Law of Action-Reaction. Examples of Newton s 3rd Law: Momentum of the car moving forward and the car comes to a sudden stop, our body pushes against the seat (action) belt and the seat belt pushes back (reaction). When you lean on the wall to rest, the weight on the wall provides the reaction force and the wall pushes back on you (reaction force) with the same force. As the gases move downward, the rocket moves in the opposite direction. Can you think of another example? Use the Arrows to show Action and Reaction in the pictures below. Sudden stop Leaning on wall Rocket lifting off Forces may move an object Forces may transfer between objects. Types of Forces Balanced Forces that are equal in magnitude but opposite in direction. Balanced forces do not cause a change in the motion of objects. Unbalanced - Force that cause a change in the motion of an object. One force must be larger than the other.

10 8.6.B differentiate between speed, velocity, and acceleration Speed is the rate used to measure the distance traveled over a period of time. Speed, Velocity & Acceleration Velocity is a measure of the speed in a given direction. Question: A green helicopter is moving up at 30 kilometers per hour. A blue helicopter is moving down at 30 kilometers per hour. A. Are the helicopters speeds the same? Explain. B. Are the velocities the same? Explain. Acceleration is the change of velocity over a period of time. If speed or direction changes, then you have acceleration. In your own words, explain the differences between speed, velocity, and acceleration. 7.7.A contrast situations where work is done with different amounts of force to situations where no work is done such as moving a box with a ramp and without a ramp, or standing still Work Work is the amount of force applied times the distance over which it is applied. In order for work to occur or happen THE OBJECT MUST MOVE IN THE DIRECTION OF THE FORCE APPLIED. Work = Force x distance W=f x d Formula chart! Solve: 1. A force of 825 N is needed to push a car across a lot. Two student push the car 35 m. How much work is done? 2. You push against the wall for 3min with a force of 10 N. How much work is done? Explain.

11 Work or No Work? Leaning Pushing Leaning on wall: Work or No Work? Lifting barbell over your head: Work or No Work? Pushing skateboard forward: Work or No Work? Standing in the rain: Work or No Work? Lifting Standing 6.8.A compare and contrast potential and kinetic energy Forms of Energy Potential Potential Energy Description of Energy Energy that is stored in an object. Example: The rubber band chicken. As the rubber band is stretched and placed in the hold position, the rubber band will store energy. Kinetic Energy Kinetic Forms of Energy Description of Energy Energy of motion; Based on the mass and speed of the moving object. Example: The flying rubber band chicken. As the rubber band is released it becomes energy in motion.

12 Potential to Kinetic Energy When the coaster is at its highest point on the track, it has it the greatest potential energy. As the coaster loses height it gains speed: PE is transformed into KE. As the coaster gains height it loses speed: KE is transformed into PE. 6.8.C calculate average speed using distance and time measurements Formula chart! Average speed = distance time s = d/t Solve: 1. You arrive in my class 45 seconds after leaving math which is 90 meters away. How fast did you travel? 2. You need to get to class, 200 meters away, and you can only walk in the hallways at about 1.5 m/s. (if you run any faster, you ll be caught for running). How much time will it take to get to your class? 6.8.D measure and graph changes in motion Graphing Motion Time (sec) Distance (m) Race Distance (meters) Time (sec) distance Speed = distance time S = d t

13 6.9.C demonstrate energy transformations such as energy in a flashlight battery changes from chemical energy to electrical energy to light energy Energy Energy is the ability to do work. Forms of Energy: 1. Electrical 2. Chemical 3. Radiant/Solar 4. Nuclear 5. Mechanical Categories of Energy Potential 1. Chemical 2. Mechanical 3. Nuclear Kinetic 1. Radiant / Sunlight 2. Thermal / Heat 3. Electrical 4. Sound 5. Mechanical * Mechanical Energy can be both potential and kinetic. Electrical Energy Forms of Energy Electrical Description of Energy Delivered by tiny charged particles called electrons, this form of energy is typically moved through a wire. Example: Lighting or Electricity Radiant Energy Forms of Energy Radiant / Solar Example: Sunshine Description of Energy Energy that travels as light Solar Energy energy from the Sun only Radiant Energy energy from all other light sources

14 Nuclear Energy Forms of Energy Nuclear Description of Energy Energy stored in the nucleus of an atom the energy that holds the nucleus together. Example: Nuclear power plants split the nuclei of uranium atoms. Thermal Energy Forms of Energy Thermal / Heat Description of Energy The vibration and movement of the atoms and molecules within substances. As an object is heated up, its atoms and molecules move and collide faster. Example: Geothermal - heat from the earth. Mechanical Energy Forms of Energy Mechanical Description of Energy Potential energy stored in objects by tension. Kinetic energy when machine parts are moving. Example: Gears or compressed spring; moving parts Sound Energy Forms of Energy Description of Energy Sound The movement of energy through substances. Sound is produced when a force causes an object or substance to vibrate. Example: Moving guitar strings

15 Chemical Energy Forms of Energy Chemical Description of Energy Energy stored within the bonds of atoms and molecules. Example: Gasoline, Batteries, or Food Energy Transformations Energy can change from one form to another. Example: Kinetic Energy can turn into potential energy and back again. Chemical Energy can be used to create Electrical Energy and Electrical Energy can be used to create Heat Energy Law of Conservation Energy cannot be created or destroyed but can only change from one form to another. Chemical - Electrical Radiant - Chemical Batteries made of chemicals Creates electricity to turn on the light bulb. Sunlight Photosynthesis produces glucose Nuclear Electrical Mechanical - Sound Nuclear Energy - Power Plant changes energy into electricity for homes Speaker movement Vibrations create sound

16 Energy Transformations Chemical - Mechanical Thermal Electrical Gas Engine turns blade to cut grass Heat from the Earth Power Plant changes it to electricity for homes

17 8.7A model and illustrate how the tilted Earth rotates on its axis, causing day and night, and revolves around the Sun causing changes in seasons 8th grade Science STAAR Review Objective 3: Earth & Space The Earth rotates or spins around its axis. The axis is an imaginary line running through the center of the earth from the North Pole to the South Pole. This rotation takes 24 hours causing the sun to rise and set (night and day). Earth s axis tilts 23.5 degrees. Earth Day & Night 1 rotation = 24 hours or 1day Earth & Sun Year & Seasons It takes just over 365 days or one year for the Earth to complete one revolution around the Sun. However because of its tilt, the Sun s rays hit the Northern Hemisphere longer and more directly in the summer the in the winter. When it s summer in the Northern Hemisphere, it is winter in the Southern Hemisphere.

18 Earth & Sun Seasons caused by tilt of the axis One hemisphere is Tilted away from the Sun and receives less direct solar rays from the Sun. The area around the Equator isn t affected by Earth s Tilt. Because it s in the middle, it will always have direct solar rays all year round. And this is the reasons for the seasons in the Northern and Southern Hemispheres. Around the equator there s only one season, Summer. QUESTIONS: 1. What is the difference between Earth s rotation and revolution? 2. Why do day and night occur? Draw a detailed picture to describe the process. Make sure to label and identify any important factors such as Earth s axis, the North Star, and the direction Earth moves. 3.. What causes seasons to occur? Use 2-3 sentences to explain the process.

19 8.7 B demonstrate and predict the sequence of events in the lunar cycle Earth, Moon & Sun Phases Description of Lunar Phases New Moon: The lighted side of the Moon faces away from the Earth. This means that the Sun, Earth, and Moon are almost in a straight line. First Quarter: The right half of the Moon appears lighted and the left side of the Moon appears dark. Full Moon: The lighted side of the Moon faces the Earth. This means that the Earth, Sun, and Moon are nearly in a straight line, with the Earth in the middle. Last Quarter: Sometimes called Third Quarter. The left half of the Moon appears lighted, and the right side of the Moon appears dark.

20 8.8 A describe components of the universe, including stars, nebulae, and galaxies, and use models such as the Hertzsprung- Russell diagram for classification Nebulae Asteroids Comet Components of the Universe Huge clouds of dust and gas. Large rock that orbits the sun Made of ice, dust & small rock. Star A star is ball of hydrogen and helium fueled by fusion. Galaxy A collection of stars held together by the gravity. Our Solar System is in the Milky Way Galaxy (Spiral). Types of Galaxies Spiral Elliptical Irregular Hertzsprung Russell Diagram

21 Star Classification Stars are classified by their spectra (the elements that they absorb) and surface temperature. There are seven main types of stars. In order of decreasing temperature, O, B, A, F, G, K, and M. O and B stars are uncommon but very bright; M stars are common but dim. An easy way to remember is: "Oh Be A Fine Girl (or guy) Kiss Me." Class Brightness Temperature Color O Brightest 30,000-60,000 Blue B 10,000-30,000 Blue- White A 7, ,000 White F 6,000-7,5000 Yellow- White G 5,000-6,000 Yellow K 3,500-5,000 Orange M Very Dim 2,000-3,000 Red Hertzsprung Russell Diagram The H- R Diagram is a graph that plots stars color (spectral type or surface temperature) vs. its luminosity (brightness). This diagram shows 3 different types of stars: 1. Most stars, including the sun, are "main sequence stars," fueled by nuclear fusion converting hydrogen into helium. For these stars, the hotter they are, the brighter. 2. As stars begin to die, they become giants and supergiants (above the main sequence). These stars have depleted their hydrogen supply and are very old. 3. Smaller stars (like our Sun) eventually become faint white dwarfs (hot, white, dim stars) that are below the main sequence. These hot, shrinking stars have depleted their nuclear fuels and will eventually become cold, dark, black dwarfs.

22 1. Use the information in the diagram below to answer the question. Massive stars tend to be either blue or white in color. What does this color tell us about these stars? 2. Use the information in the diagram above to answer the question. The Herztsprungn Russell diagram classifies stars by their surface temperature and luminosity. If a star has a low surface temperature and is considered very dim, where would you expect it to be located on the Herztsprungn-Russell diagram? 3. Which of the following can be found in galaxies? A. Stars, interstellar gas, and dust B. Stars, mini- galaxies, dust C. Dust, gas, and millions of black holes D. Lenticular galaxies and irregular galaxies 4. What are black holes, and how are they created? 5.What are nebulae, and how are they important? 6. How are stars different from each other? 7.What is the Herztsprung- Russell Diagram, and how is it used to classify stars? 8. How are galaxies classified?

23 8.9 B relate plate tectonics to the formation of crustal features Plate Tectonics Plate Tectonics is the movement of large sections of the Earth s crust called Tectonic Plates. The plates are like the skin of the planet. They constantly move. When we say moving, we're talking centimeters each year. Plate Boundaries The tectonic plates are floating on top of magma which causes them to move. Tectonic plates collide with one another along the Plates Boundaries. There are several types of plate boundaries. 1. Transform 2. Divergent 3. Convergent Caused by convection currents in the magma.

24 Transform Boundary Type of boundary Transform Description Where the two plates slide against each other in a sideways motion. Occasionally this energy is released suddenly in the form of large earthquakes. sideways Divergent Boundary Type of boundary Description Divergent Where two tectonic plates are moving away from one another. Examples: - mid- ocean ridge - fault block mountains - rift valleys

25 Convergent Boundary Convergent Type of boundary Description Where two plates push against each other. As two plates rub against one another, a number of small and large earthquakes are common near convergent boundaries. There are 3 kinds of Convergent Boundaries: A. Oceanic Plate to Oceanic Plate B. Oceanic Plate to Continental Plate C. Continental Plate to Continental Plate A. Convergent Boundary: Oceanic Plate to Oceanic Plate Kind of Convergent Boundary Oceanic Plate to Oceanic Plate Description When two oceanic plates converge, one is usually subducted under the other, and in the process a trench is formed. B. Convergent Boundary: Oceanic Plate to Continental Plate Kind of Convergent Boundary Description of Energy Oceanic Plate to Continental Plate When an oceanic plate and continental plate converge, one is usually subducted under the other causing volcanoes and mountains.

26 C. Convergent Boundary: Continental to Continental Plate Kind of Convergent Boundary Continental to Continental Plate Description of Energy When two continental plates converge, one is usually subducted under the other causing mountains. QUESTIONS: 1.What features of Earth s crust do convergent, divergent, and transform boundaries form? 2. What land features formed by the movement of tectonic plates can be observed using images from space? 3. Which layer contains the tectonic plates? A. Core B. Asthenosphere C. Lithosphere D. Atmosphere

27 4. What crustal feature may be formed when the two plates shown below collide? 5. How has satellite technology supported Plate Tectonic Theory? a. Can see crustal features have formed along boundaries b. Actual movement of the plates can be seen c. Can see how the continents once fit together d. Can predict earthquakes and volcanic eruptions 8.9 C interpret topographic maps and satellite views to identify land and erosional features and predict how these features may be reshaped by weathering Topographic Maps Topographic Maps are 2- D drawings of 3- D land features. A topographic map is often a very large scale map that shows the shape of the land s surface. Contour lines are imaginary lines that connect places of equal elevation. When contour lines are close together, the slope is very steep. When contour lines are far apart, the slope is very shallow. Scenario A: Look at diagram below to answer the questions that follow. The top of this drawing is a topographic map showing the hills that are illustrated at the bottom. On this map, the vertical distance between each contour line is 10 feet. Which is higher, hill A or hill B? Which is steeper, hill A or hill B? How many feet of elevation are there between contour lines? How high is hill A? How high is hill B?

28 Scenario B: Satellite Views/ Erosion Satellite views- Images taken over time that can be used for comparison and interpretation of erosional features such as these taken of the Yellow River Delta. What happened to the land between 1989 and 2009? Scenario C: Study the diagram above showing an island before and after a hurricane. What most likely caused the changes to the island seen in the diagram? A The rainwater from the hurricane raised the level of the ocean. B The island sank deeper into the ocean during the hurricane. C Ocean waves caused by the hurricane eroded sand from the beaches. D Rivers on the island deposited new sand on the beach. Scenario D: Define and give examples of erosion, decomposition, and weathering.

29 8.7 C relate the position of the Moon and Sun to their effect on ocean tides Tides Tides are the periodic rise and fall of the ocean waters. They are caused by the gravitational pulls of the Moon and Sun, as well as the rotation of the Earth. The Sun and Moon pull on the Earth, the water, even you! Spring Tide Neap Tide

30 8.8 B recognize that the Sun is a medium- sized star near the edge of a disc- shaped galaxy of stars and that the Sun is many thousands of times closer to Earth than any other star The Sun Did you know? Our Sun is a medium size yellow star near the edge of a disc-shape galaxy of stars. The Sun is many thousands of times closer to Earth than any other star. QUESTIONS: 1. Which of the models below is the best representation of the location of the Sun in the Milky Way galaxy? 2. Describe the location of our Sun and other stars near it in relation to the Milky Way galaxy. 3. Compare a planet, a star, and a galaxy in terms of: (a) size (b) light emitting ability and (c) location. Components of Universe Planet Size Light emitting ability Location Star Galaxy

31 8.8 C explore how different wavelengths of the electromagnetic spectrum such as light and radio waves are used to gain information about distances and properties of components in the universe Electromagnetic Spectrum Electromagnetic Waves have different wavelengths. Waves in the electromagnetic spectrum vary in size. All electromagnetic waves travel at the same speed - the speed of light. Radio waves and visible light are types of electromagnetic waves. They differ from each other in wavelength. Wavelength is the distance between one wave crest to the next. Other examples are microwaves, infrared, ultraviolet, X- rays and gamma- ray. Each type of wave on the spectrum has a different effect and use. Scientists use the electromagnetic radiation given off by components in the universe to measure distances in space and the composition of objects in our universe. Radio Waves Objects in space, such as planets, comets, giant clouds of gas, stars and galaxies, give off light at many different wavelengths. Some of the light they give off has very large wavelengths sometimes as long as a mile! Radio telescopes look at planets, comets, giant clouds of gas, stars and galaxies. By studying the radio waves originating from these sources astronomers can learn about their composition, structure, and motion. Radio astronomy has the advantage because sunlight, clouds, and rain do not affect observations. Radio Telescope

32 Electromagnetic waves are important because they provide scientists with important information about components of our universe. Electromagnetic waves are also used to measure distance in space. How the EM spectrum can be use to gain in information about the Properties of Components in the Universe Images from telescopes engineered to detect different types of electromagnetic radiation show the same astronomical object in different ways. Skilled observers can recognize certain properties of the object from these images. For instance, in the case of a nebula, the gaseous remnant of an exploding star, the color and intensity of visible light and other portions of the spectrum indicate which elements are present and in what quantity. Infrared images provide information about planets, comets, newly forming stars, and other relatively cool bodies. X- ray telescopes capture and show radiation from very hot regions in stars and from violent events like explosions or collisions. Crab Nebula X-Ray Crab Nebula Infrared X-ray, Infrared, Visible Light Waves Visible light waves are the only electromagnetic waves we can see. We see these waves as the colors of the rainbow. Each color has a different wavelength. Red has the longest wavelength and violet has the shortest wavelength. When all the waves are seen together, they make white light. Visible light helps scientists understand the chemical composition of stars.

33 QUESTIONS: 1. How do astronomers use the electromagnetic spectrum to gain information about the properties of the components of the universe? 2. How do astronomers know that galaxies are moving away from Earth? 3. Look at the electromagnetic spectrum provided above. What kind of waves are the longest in the electromagnetic spectrum? 4. Which one of the choices below is the best representation of a Gamma Ray? 5. Look at the electromagnetic spectrum. List the following waves in order of HIGHEST to LOWEST frequency. (gamma rays, radio waves, orange light, infrared rays, microwaves, violet light) 6. What are radio telescopes used for? 8.8 D model and describe how light years are used to measure distances and sizes in the universe Light Years Distances in space are SO large that is does not make sense to use a typical unit such as kilometers or miles when measuring distances. Instead, astronomers use a special unit called a light- year to measure the distance between stars and galaxies. A light- year is the distance that light travel in one year. Proxima Centauri is 4.3 light- years away. It takes 4.3 years for light from this star to travel the distance needed to reach Earth. Speed of light = 300 million meters per sec or 186,282 miles per sec!

34 8.9 A describe the historical development of evidence that supports plate tectonic theory Theory of Continental Drift Theory of Continental Drift was proposed by Alfred Wegener in the early 1900 s. Theory stated that the continents were once joined in a large land mass called Pangaea. They have been drifting away from each other for millions of years. Pangaea Pangaea - This super- continent was made up of all the continents on Earth. Over time, these continents have broken apart, and slowly drifted away from one another. This drift continues today. Pangaea Evidence of Continental Drift 4 Pieces of Evidence Supported Wegener s Theory 1. The continents fit together like puzzle pieces. 2. Similar fossils were found on opposite continents. 3.Similar land features (like mountain ranges) were found on opposite continents. 4. Tropical regions have evidence of once being arctic glaciers, which suggests the continents have moved over time.

35 QUESTIONS: 1. A scientist found fossils of the same tropical fern in Africa, Antarctica, and Australia. What conclusion can the scientist make? A. The fern can live in any climate B. Birds who eat the fern also live in Africa, Antarctica, and Australia. C. More evidence is needed to make a good conclusion. D. The continents have moved. 2. Explain in your on words the Theory of Plate Tectonics. 3. If a photo of Earth, from space, was taken 25 million years from now, would the landmasses appear the same as they currently do or different? Why do you think this? 8.10 A recognize that the Sun provides the energy that drives convection within the atmosphere and oceans, producing winds and ocean currents Unequal Heating in the Oceans and Atmosphere The source of almost all Earth s heat energy is the Sun. The Sun gives off its heat in the form of electromagnetic radiation, which travels through space. The Sun s heat is distributed throughout the atmosphere, land, and the oceans by radiation, conduction, and convection, providing the energy to make weather.

36 Ocean Currents Ocean currents are mainly caused by wind and differences in temperature. Currents are responsible for a vast amount of movement of the water found in the Earth s oceans. The ocean plays a starring role in whatever happens with the environment. One big part of its role is to soak up energy (heat) and distribute it more evenly around the Earth. Ocean currents influence the weather in coastal areas. Wind Currents High pressure Low pressure Wind can be defined as air moving from an area of high pressure to an area of low pressure in the atmosphere. The greater the difference between high and low pressures, the faster the air moves. If all areas across Earth s surface had the same air pressure, there would be no wind. The Sun, however, heats some parts of Earth more than others, creating pressure differences. Thus, winds are driven by solar energy. QUESTIONS: 1. What is the source for almost all of Earth s energy? 2. Are all areas of Earth equally heated by the Sun? Why or why not?

37 8.10 B identify how global patterns of atmospheric movement influence local weather using weather maps that show high and low pressures and fronts Weather Map A weather map or chart shows the weather conditions at a specific point in time over Cold Front Forms at the surface of Earth when a cold, dry air mass overtakes a warmer, humid air mass Cold fronts are fast moving with steep frontal boundary that force the warm air to rise quickly, resulting in rapid phase changes. Cold fronts are characterized by dramatic storms, cumulonimbus clouds, thunder, lightning and sometimes tornadoes. Precipitation occurs at the frontal boundary and tends to be heavy but of short duration; local air temperature changes from warm to cool after the front passes.

38 Warm Front Forms at the surface of Earth when a warm, moist air mass overtakes a cool, dense and dryer air mass Precipitation occurs ahead of the frontal boundary and tends to be prolonged but gentle; local air temperature changes from cool to warm after the front passes. QUESTIONS: 1. What is the density of air over an area called as symbolized in the graphic below?

39 8.10 C identify the role of the oceans in the formation of weather systems such as hurricanes Oceans Affect Climate On Land When the sunrays hit the surface of the Earth, it is heated. However, there is big a difference between how fast the land and the sea are heated. The land is heated a lot faster than the sea. The air above land is heated faster than the air above the sea. The hot air above land rise high into the sky, where it cools off. High in the sky the cold air now moves out over the sea. Here it sinks down pressing cool air towards land. The air moving towards land is what we know as wind (convection current). At night the opposite happens. That means it is the sun that makes the wind blow. Warm air holds more water vapor than cold air does. When warm, moist air is cooled, clouds form and can produce precipitation (rain or snow). This warm air can be cooled by rising into the colder upper atmosphere, by moving over cold ocean or lakes or by mixing with colder air. Example: A Front Boundary The edge where cool, dry air meets warm, moist air often causes stormy weather. Hurricanes Hurricanes get their energy from warm ocean waters. As ocean water increases in temperature, it slowly turns into water vapor. The warmer the water temperature is, the higher the water vapor rises. After the water vapor has risen, it begins condensing into rain in the form of clouds. When the clouds release the rain, heat is released as well. When this heat stays in the same area, the eye of the hurricane is formed.

40 7.8 C model the effects of human activity on groundwater and surface water in a watershed Watershed Watershed - An area of land where all water from rain and melted snow that is under land or drains off of land goes into a larger body of water. Watershed Parts Surface Water Description Water above the Earth s surface that eventually moves into a river, stream, or lake. Ground Water Water that seeps into the ground but eventually moves into a river, stream, or lake. Aquifer A groundwater reservoir that can store and release large amounts water below the surface Infiltration The process of surface water entering the soil

41 Human Effects on Watersheds Overdraft Over- use or overdraft can cause problems to humans & the environment. One big problem is a lowering of the water table beyond the reach of existing wells. Subsidence Subsidence occurs when too much water is pumped out from underground causing the ground to actually collapse. Causes sinkholes. Pollution Pollution of groundwater from pollutants released to the ground can work their way down into groundwater and contaminant an aquifer B understand that gravity is the force that governs the motion of our solar system Newton s Law of Universal Gravitation The law that says every object in the universe attracts every other object

42 Our Solar System Our solar system resides in the Milky Way galaxy and is made up of the Sun, eight planets, and many moons, asteroids, meteoroids, and comets. All of the celestial bodies in the solar system move in predictable patterns known as orbits, and this motion is controlled by gravity. Gravity is a force of attraction between two or more masses. Everything that has mass has gravity. The more mass you have, the stronger the gravitational force you give off. For example, Earth has more mass than the Moon, so its gravitational field is stronger. So what planet do you think should be listed as having the greatest gravitational force? In addition, as the distance between two masses increases, the gravitation attraction between them decreases. For example, Earth s gravitation pull on us is strongest when we are standing on its surface compared to if we were floating in space, thousands of miles away.

43 Which diagram above, A or B, has the greatest gravitation attraction? The celestial body in our solar system with the most mass and hence strongest gravitational force is the Sun. Because the Sun has the strongest gravitation field, it has the strongest influence on the motion of the other bodies in the solar system (i.e., planets). Celestial objects, such as planets, moons, asteroids, comets, meteors, and even satellites, move within the solar system, around more massive objects (e.g., the Sun), along paths known as orbits. These paths are determined by the momentum with which these objects are travelling and by the gravitational force they experience from other, more massive objects. For example, Earth s orbit around the Sun is determined by the balance of the Sun s gravitational pull on Earth and Earth s momentum as it travels around the Sun. Without the Sun s gravitational pull, Earth would not move in a circle around the Sun, but would continue moving straight throughout the Milky Way. Without Earth s momentum, the Sun would pull Earth into it. YIKES!

44 Explain to your partner why the planets do not crash into each other. QUESTIONS: 1. Why do the planets in our solar system orbit the Sun? A. The Sun has the strongest magnetic pull B. The Sun is the celestial body with the greatest mass C. The Sun is the brightest celestial body in our solar system. D. The Sun was created millions of years before our planet. 2. Which two forces control the orbit of a planet? A. The force of motion and the force of the Sun B. The force of gravity and the force of motion C. The force of Newton and the force of gravity D. The force of attraction and the force of planetary motion 3. Examine the figure below. Which objects show the strongest gravitational force of attraction? A. The Sun and Planet A because Planet A has a greater mass than planet B. The Sun and Planet B because Planet B has a greater mass than planet A C. The gravitation force of attraction is the same between the Sun and planet A and between the Sun and planet B. D. None of these answers are correct

45 8th grade Science STAAR Review Objective 4: Organisms & Environment 8.11 A describe producer/consumer, predator/prey, and parasite/host relationships as they occur in food webs within marine, freshwater, and terrestrial ecosystems ECOSYSTEM - an ecosystem includes the biotic (living) and abiotic (non - living) parts of the environment. Food Chain The path of food energy from the sun to the producer then transferred to a series of consumers Arrows show the flow of energy. Note: The sun provides energy to plants to produce food in the process called Photosynthesis. Food Web - A model that shows all the possible feeding relationships between organisms living in an ecosystem. Energy flows through various food chains as animals eat plants and predators consume prey, creating a food web. The energy that flows though food chains and food webs comes from the Sun. Trophic levels of organisms in a food web range from primary producers (autotrophs), and different levels of heterotrophs, including primary consumers (herbivores), secondary consumers (carnivores that eat herbivores), and tertiatry consumers (carnivores that eat carnivores).

46 AQUATIC ECOSYTEMS Aquatic ecosystems include freshwater and marine biomes and constitute the largest part of the biosphere. In marine ecosystems, phytoplankton are autotrophic producers and are consumed by zooplankton and small invertebrates, which are consumed secondarily by fish and larger marine life. Question: What is the main difference between freshwater and marine ecosystems? Question: Give an example of a predator/prey in this ecosystem. TERRESTRIAL ECOSYSTEMS A terrestrial ecosystem is an ecosystem that is found on land. In terrestrial ecosystems, the primary producers are plants, which are consumed by insects, arthropods, and grazing animals. Secondary consumers include spiders, frogs, and carnivorous animals. Question: Give an example of a predator/prey in this ecosystem.

47 Symbiosis Parasitism is an interaction between two organisms, in one organism benefits (the parasite) and the other organism is harmed (host). Mutualism is an interaction between two organisms, in which there is benefit to both. Commensalism is an interaction between two organisms, in which one benefits and the other is not affected. Words you need to know: A producer is an organism that is able to produce its own food, usually by using energy from sunlight to make sugars (photosynthesis). A consumer is an organism that eats other organisms for energy. Ex: plants Ex: herbivores, carnivores, omnivores, and scavengers A decomposer is an organism that gets energy by breaking down the remains of dead organisms or organic wastes and consuming or absorbing nutrients (recycle nurients). Ex: fungi and bacteria

48 A herbivore is an organism that consumes only plants Ex: Giraffe, rabbits, cows A carnivore is an organism that consumes other animals An omnivore is an organism that consumes both plants and animals Ex: hawks, tigers A parasite is an organism that survives on a host organism and causes harm to the host. Ex. Humans, bears A host is an organism that is used by another for nutrients, shelter, or transport; it is harmed by the relationship A prey is an organism that is hunted by other organisms for food Ex. Insects that eat tomatoes Ex. Humans are host for mosquitoes A predator is an organism that hunts for its food Prey Predator

49 8.11 B investigate how organisms and populations in an ecosystem depend on and may compete for biotic and abiotic factors such as quantity of light, water, range of temperatures, or soil composition Biotic & Abiotic Term Definition Examples Biotic factors are the living parts of an ecosystem Animals (ex. Horses, dogs) Plants (ex. Trees, grass) Fungi (ex. mushroom) Microorganism (ex. bacteria) Abiotic Factors are the non living parts of an ecosystem Sunlight Air Temperature Water Soil Wind Clouds Competition for Biotic & Abiotic Biotic Competition Abiotic Competition Competing for food Competing for sunlight Resources for an organism s habitat, including space, food, shelter, and water, may be limited or depleted by competition. Two species cannot operate in the same niche in the same environment.

50 DEFINITIONS you must know. A population is a group of living organisms of the same kind living in the same place. Ex. Group of polar bears A niche is an organism s job or role in an ecosystem. A community is ALL species or populations living in the same area. Examples: A ladybug eating aphids Competition occurs when more than one individual, or populations in an ecosystem relies upon the same limited resources. Examples of limited resources: food, water, territory Two types of competition: a. Intraspecies competition: occurs when members of the same species compete for same resources in an ecosystem b. Interspecies competition: occurs when individuals of two separate species share a limiting resource in same area. Invasive species vs. native species An "invasive species" is defined as a species that is non- native (or alien) to the ecosystem under consideration and whose introduction causes or is likely to cause economic or environmental harm or harm to human health.

51 8.11 C explore how short- and long- term environmental changes affect organisms and traits in subsequent populations Short- Term and Long- Term Environmental Change Effects Adaptations are traits that make an animal suited to its environment. Two Types: Structural Adaptations are inherited physical features of and organism. (Ex. White fur on a polar bear) Behavioral Adaptations are things organisms do to survive. (Ex. Migration & hibernation) Biodiversity-The number of different species of plants and animals in an area Short Term and Long Term Environmental Changes Short-Term - Drought - Smog - Flooding - Volcanic Eruption - Blizzard - Pollution Long-Term - Ice Age - Deforestation - Urbanization - Global Warming - Extinction of Species - Radioactive Waste/Pollution Changes in environmental conditions can affect the survival of individual organisms and entire species. Long- term environmental changes, like climate change, can permanently alter an ecosystem, but over time the change may cause some genetic variations to become more favorable or less favorable in the new environment. If adaptations to the new environment are not present or do not develop, populations can become extinct.

52 Short- term environmental changes, like "floods, don t give populations time to adapt to change and force them to move or become extinct. Human activity affects natural systems through agriculture, resource consumption, and pollution from waste disposal and energy production D recognize human dependence on ocean systems and explain how human activities such as runoff, artificial reefs, or use of resources have modified these systems Dependence on Ocean Systems Humans depend on the ocean for: Weather, Food, Transportation and Recreation Overfishing Humans modify by: personal sport, commercial harvesting Artificial Reefs man made underwater structure to promote marine life such as a sunken ship Run Off chemicals and trash flow to the ocean from rivers and streams

53 Human activity such as runoff pollution can originate from small or large sources on land and water, including motorized vehicles, oil spills, agricultural chemicals, and recreation. Runoff pollution negatively affects beaches and ocean habitats. Overharvesting food from the ocean creates an imbalance in existing ocean food webs. (What does overharvesting mean and how would this cause an imbalance?) Other examples of the effects of human activity on oceans include climate change, spread of disease, and introduction of exotic species. Climate Change Disease Exotic species/invasive 7.10 B describe how biodiversity contributes to the sustainability of an ecosystem BIODIVERSITY The number of different species of plants and animals in an area Biodiversity, or biological diversity, is the variety of life and the intricate interactions that support and link organisms together in a geographical region. Biodiversity includes a variety of genes, species, and ecosystems. The higher the biodiversity of an ecosystem, the better that ecosystem can withstand environmental stress. Hence, if biodiversity is lost, that ecosystem has less ability to withstand the same environmental stress C observe, record, and describe the role of ecological succession such as in a microhabitat of a garden with weeds Ecological Succession The gradual replacement of one plant community by another through natural processes over time Primary Begins in a place without soil (Side of a Volcano) Starts with Pioneer Spices (like Lichen that doesn t need soil). They die /decompose and leave behind organic matter on bare rock to make soil. Then simple plants, grass, shrubs, trees grow and die to provides home to insects, birds and small mammals. Secondary - Begins in a place that already has soil and was once the home of living organisms. Example.. After forest fires.

54 Following a major disturbance, such as natural disaster, a progression of re- building occurs. Weeds, small insects, and other pioneers will move into the disturbed area first. This literally lays the foundation for other species to move into the area, and the progress continues. This is referred to as ecological succession. Vocabulary you need to know: Habitat A place where an organism naturally lives and grows Microhabitat A very small specialized habitat, such as the space under a rock Succession (Ecological Succession) small pond or in a schoolyard tree. Transition of species present in a community in an area virtually barren of life, or after a disturbance QUESTION: A very hot wildfire burns up an acre of prairie. Organisms above and below ground get wiped out, and even the abundance of soil nutrients suffers. What will happen first in the area s recovery? A. Organisms will return to the soil B. Weeds will return. C. Humans will plant saplings D. Rain will bring nutrients

55 7.11 A examine organisms or their structures such as insects or leaves and use dichotomous keys for identification Dichotomous Key Dichotomous Key - a tool that allows the user to determine the identity of items by their characteristics, such as insects, leaves, trees, mammals, reptiles and others. Follow the clues in a dichotomous key to identify the organism! Based on the observation data and key below, what is the correct identification for the three arachnids? Arachnid #1 s identity: Arachnid #2 s identity: Arachnid #3 s identity:

56 7.11 C identify some changes in genetic traits that have occurred over several generations through natural selection and selective breeding such as the Galapagos Medium Ground Finch (Geospiza fortis) or domestic animals Changes in Genetic Traits - Natural Selection Natural Selection - the basic concept by Charles Darwin is that environmental conditions (or "nature") determine (or "select") how well certain traits of organisms can survive and be passed on; organisms missing these traits might die before reproducing. As long as environmental conditions remain the same, the traits that help them survive will become more common within the population. Natural Selection There is a variation in traits. For example, some beetles are green and some are brown. There is a degree of difference in reproduction. Since the environment can't support unlimited population growth, not all individuals get to reproduce to their full potential. In this example, green beetles tend to get eaten by birds and survive to reproduce less often than brown beetles do. There is heredity. The surviving brown beetles have brown baby beetles because this trait has a genetic basis. End result: brown colored beetle have more offspring, becomes more common in the population. Darwin's finches are an excellent example of the way in which species' gene pools have adapted in order for long term survival through their offspring. The Darwin's Finches diagram shows the way the finch has adapted their becks to take advantage of feeding on different foods in different ecological niche. Selective Breeding Selective Breeding - is the process of breeding plants and animals for particular genetic traits. Such as the various breeds of dogs.

57 Adaptation A process by which a population becomes better suited to its habitat; a genetic variation that provides an advantage to survive and reproduce, generally spreads through the population Bird Adaptation Bird feet have adapted through natural selection B identify the main functions of the systems of the human organism, including the circulatory, respiratory, skeletal, muscular, digestive, excretory, reproductive, integumentary, nervous, and endocrine systems Human Body Systems Endocrine System Function: Regulates body by secreting hormones into the bloodstream, such as insulin Helps body maintain homeostasis Also controls growth, reproduction and metabolism Includes: Glands and hormones

58 Circulatory System Function: Transport blood throughout the body via the heart, veins (blood flows to the heart) and arteries (blood flows away from the heart). Includes: Heart Arteries Veins Blood Respiratory System Function: Supplies blood with oxygen in the lungs and removes carbon dioxide. Includes: Airways, such as the trachea, as well as lungs, and alveoli Skeletal System Function: Support the body Protects internal organs Makes red blood cells Includes: Bones and joints

59 Muscular System Function: Provides movement to the body Contract (become shorter) Relax (become longer) Provides strength, balance, and warmth Includes: Muscles, ligaments and tendons There are three types of muscles: skeletal, smooth, and cardiac Digestive System Function: Breaks down food Absorbs nutrients Includes: Mouth, esophagus, stomach, small and large intestines, and anus Excretory system Function: Filters the blood (kidney) Removes waste in the form of fluids (urine). Includes: Kidneys and bladder

60 Reproductive System Function: Male- to produce and deliver sperm Female- to produce ova and prepares the female s body to nourish a developing embryo Function: Integumentary System Helps regulates temperature Protects the body from the outside world Includes: Skin, hair, nails and sweat glands. Nervous System Function: Network that relays messages back and forth from the brain to different parts of the body Functions as the control center, coordinating all actions and reactions Includes: Brain, spinal cord, and nerves

61 7.12 D differentiate between structure and function in plant and animal cell organelles, including cell membrane, cell wall, nucleus, cytoplasm, mitochondrion, chloroplast, and vacuole Differentiate: Structure and Function Plant & Animal Cells Plant Cell Animal Cell Plant Cells have a chloroplast and a cell wall. Animal cells do not. Plant Cell Similarities Animal Cell

62 STRUCTURE & FUNCTION of Plant and Animal Cell Organelles Organelles Function In plant, animal, or both? Nucleus Controls the cell & contains genetic material In both Cytoplasm The jellylike material that makes up much of a cell inside the cell membrane, and, in eukaryotic cells, surrounds the nucleus. Supports and protects organelles In both Mitochondrion Provides energy for the cell In both Vacuole Stores water and food/waste vacuole In both Cell Membrane Controls movement of materials in & out of cell and a barrier between cell and its environment In both cell membrane

63 Cell Wall Supports and protects the cell Chloroplast The green organelle in plant cells that converts light energy into chemical energy. Uses energy from the sun to make food (photosynthesis) Only in PLANT cells! Only in PLANT cells! 7.12 F recognize that according to cell theory all organisms are composed of cells and cells carry on similar functions such as extracting energy from food to sustain life Cell Theory - The most basic unit of living system and all living things are made up of cells Cells are the structural and functional units common to all living organisms. A cell is the smallest unit of life that is classified as a living thing. Some organisms are unicellular, meaning they consist of only a single cell. Most bacteria are unicellular. Other organisms, including humans, are multicellular, consisting of many cells. For example, humans have about 100 trillion cells. All cells need genetic and environmental information in order to function. The cell theory states that new cells come from old survive. Cells use a series of chemical reactions to break down nutrients in food to create energy and produce waste through a process called metabolism. Cells use energy from food to carry on life. Cellular respiration (heterotrophs) The process of using oxygen to break down nutrients to release energy for the cell Photosynthesis (autotrophs) Process by which plant cells make food using water, carbon dioxide, and light from the Sun

64 To carry out their day to day functions, cells require energy. The ultimate source of this energy is the sun. Some organisms can trap energy directly from the sun, storing it away to used for energy. These organisms are called autotrophs. Autotrophs can make their own food. This process is called photosynthesis. Organisms which are not capable of photosynthesis are called heterotrophs, and must get their energy through their diet instead. Cellular respiration is the process of breaking down carbohydrates, fats and proteins (obtain from diet) to release energy that can be delivered to each cell for use. To convert the energy stored into a form that is usable, both autotrophs and heterotrophs must take large molecules and break them down into smaller, easier to use molecules B compare the results of uniform or diverse offspring from sexual reproduction or asexual reproduction Asexual Reproduction Only 1 parent Offspring exactly like parent genetically (uniform) Asexual & Sexual Examples Uniform or Diverse offspring? Budding Fission uniform Sexual Reproduction Requires 2 parents Offspring is different from each parent (diverse) diverse

65 In asexual reproduction of prokaryotic cells, DNA is replicated from the parent resulting in uniform offspring. These cells divide by binary fission. Organisms composed of eukaryotic cells can also reproduce asexually by forming spores, by budding, or by vegetative propagation. In sexual reproduction of eukaryotic organisms, DNA is combined and unique combination of dominant and recessive traits from two parents create diverse offspring C recognize that inherited traits of individuals are governed in the genetic material found in the genes within chromosomes in the nucleus Genetic Material Gene - a unit of instructions for traits, found in the DNA of an organism. Genes play an important role in determining physical traits (how we look). DNA is located in chromosomes in the nucleus Humans have 23 pairs of chromosomes Traits - characteristics that distinguish an organism. Inherited Traits - traits that are inherited in the genes and passed down from parent to offspring (generation to generation) Type of Inherited Trait Genes are located in the Chromosomes in the Nucleus Attached Ear Lobe Hanging Ear Lobe Genetic information is inherited from both parents in sexual reproduction. Inherited traits include expressed external characteristics such as eye color and hair color and internal characteristics such as blood type. Inherited traits are not affected by the organism s surroundings.

66 VOCABULARY YOU NEED TO KNOW : Heredity: Process of characteristics transmitted from parent to offspring. Genes: The basic physical and functional unit of heredity made up of DNA. Genotype: A genetic makeup of an organism Example: Bb (brown hair dominant) Phenotype: The physical appearance of an organism Example: long body, brown hair, etc. Trait: A characteristic of an organism controlled by genetics. Example: color Alleles: Variations of a gene relating to the same trait. Allele for purple flower Heterozygous: Having two different alleles for a trait. Example: Bb in picture to your right. Allele for red flower Homozygous: Having two of the same alleles for a trait. Example: BB or bb in picture to your right.

67 6.12 D identify the basic characteristics of organisms, including prokaryotic or eukaryotic, unicellular or multicellular, autotrophic or heterotrophic, and mode of reproduction, that further classify them in the currently recognized Kingdoms Characteristics of Organisms Prokaryotic Does not have an organized nucleus. Their DNA is floating around the cell. Eukaryotic Has a nucleus. Autotrophic Organisms that make their own organic food Heterotrophic Organisms that consume food that is already present in the environment Three domains are used to classify or group organisms. DOMAIN Description Examples Archae Primitive unicellular prokaryotes; some autotrophs and some heterotrophs; some live in harsh conditions Bacteria Eukarya Unicellular prokaryotes; most are heterotrophs; typical bacteria Unicellular and multicellular eukaryotes Halophilic archae live in very salty water Staphylococcus bacteria, E. coli Fish, tree, algae