What would make the results of an experiment carried out by a research team VALID or more RELIAABLE? • The experiment was repeated and the same results were obtained each time. • Use a larger sample size. The ________________does not contain the independent variable. control group What is MEASURED is known as the ______ variable. dependent A new idea that is tested in a scientific experiment is known as a(an) 1. theory 2. hypothesis 3. inference 4. observation The hypothesis is based on the 1.conclusion 2.dependent variable 3.data collected 4.background research To investigate the effect of a substance on plant growth, 2 bean plants of the same species were grown under identical conditions with Substance Z added to the soil of one of the plants. At the end of 2 weeks, the plant grown with Substance Z was 12.5 cm tall. The plant grown without Substance Z was 12.2cm tall. The researcher concluded that the presence of Substance Z causes the plants to grow taller. 1. Identify the independent variable. Substance Z 2. Identify the dependent variable. Plant height (how tall the plant grew) To investigate the effect of a substance on plant growth, 2 bean plants of the same species were grown under identical conditions with Substance Z added to the soil of one of the plants. At the end of 2 weeks, the plant grown with Substance Z was 12.5 cm tall. The plant grown without Substance Z was 12.2cm tall. The researcher concluded that the presence of Substance Z causes the plants to grow taller. 3. Identify the control group. The group that did not receive Substance Z. 4. Identify the experimental group. The group that received Substance Z. To investigate the effect of a substance on plant growth, 2 bean plants of the same species were grown under identical conditions with Substance Z added to the soil of one of the plants. At the end of 2 weeks, the plant grown with Substance Z was 12.5 cm tall. The plant grown without Substance Z was 12.2cm tall. The researcher concluded that the presence of Substance Z causes the plants to grow taller. 6. Identify 2 constants or controls. Same species Amount of water Amount of sunlight Temperature To investigate the effect of a substance on plant growth, 2 bean plants of the same species were grown under identical conditions with Substance Z added to the soil of one of the plants. At the end of 2 weeks, the plant grown with Substance Z was 12.5 cm tall. The plant grown without Substance Z was 12.2cm tall. The researcher concluded that the presence of Substance Z causes the plants to grow taller. 7. How can the results of this experiment be made more valid? Repeat the experiment. Use a larger sample size. 2cm 5cm 3cm Determine the volume of this object. 3cm x 30cm3 2cm x 5cm = 2cm 5cm 3cm Identify the type of solid represented. This is a regular solid because it has a length, width and height. 1. What is the volume of this toy dinosaur? 0.8mL (5.6mL – 4.8mL) 2. What is the name of this method? displacement 3. Identify the type of solid being measured. An irregular solid 1. What is the definition of mass? The amount of matter in an object. 2. What is the name of the instrument used to measure mass? triple beam balance 3. What are the units used to measure mass? grams 1. Identify the amount of space an object takes up. VOLUME 2. Identify the units for the volume of a regular solid. cm3 3. Identify the units for the volume of a liquid. mL 4. Identify the units for the volume of a irregular solid. mL or cm3 0 cm 1 2 3 4 What is the length of the object in centimeters? Millimeters? 2.8cm 28mm 1. How is the density of an object measured? D = M/V 2. What is the density of a 100gram object with a volume of 20 milliliters? 100g/20mL = 5g/ml 3. The object above was cut into three pieces. What is the density of one of those pieces? 5g/ml The density of an object DOES NOT CHANGE!!!! Explain why an object placed in a glass of water floats. The object has a density less than the density of water (1g/ml). Give the name and function of each structure labeled. E A – Ocular: eyepiece used to look at specimen B – Fine adjustment: to focus specimen under high power C – Arm: used to hold microscope D – Objective lens: used to magnify image E – Coarse adjustment: Used to focus specimen under low power F – Diaphragm – adjust amount of light reaching specimen F What was the highest possible magnification that can be obtained when using this microscope? E Objective - Ocular 40 x 10 = 400x F What happens to the field of view when switching from low to high power? E The field of view decreases ( so you see less of the slide). F Which structure can only be used to focus the specimen under high power? Support your answer. The fine adjustment because using the coarse adjustment under high power can break the objective lens or the slide. E F What happens to the number of cells that are visible in the field of view when switching to high power? The number of cells that are visible in the field of view decreases. What must be done to the microscope before switching from low power to high power? Center the specimen Focus with the coarse adjustment The total magnification of an image is the result of the combined magnifications of the 1) eyepiece and diaphragm 2) objective and eyepiece 3) objective and mirror 4) low-power and high-power objectives Identify the life process described. 1. Used to produce energy. Respiration 2. Type of nutrition in which organism produces its own food. Autotrophic nutrition 3. The movement of substances throughput a cell or organism. Transport 4. Type of nutrition that requires an organism to ingest food. Heterotrophic nutrition 5. The removal of metabolic wastes. Excretion 6. Type of respiration that does not use oxygen. Anaerobic respiration 7. Sum total of all life processes. Metabolism 8. Control and coordination of all life processes. Regulation 9. Maintaining a stable internal environment. Homeostasis 10. Type of respiration that uses oxygen. Aerobic respiration Identify the structures labeled and the function of each. 1- nucleus: controls all cell activities 2 – nucleolus: produces ribosomes 3 – cell membrane: controls what enters and exits the cell 4 – cytoplasm: holds cell organelles 5 – cell wall: keeps plant cells RIGID and supports plant cell 6 – vacuole: stores materials 7 - chloroplast: site of photosynthesis (autotrophic nutrition) The structures inside a cell that perform life activities are called (1)organs (2)systems (3)organelles (4)cells One difference between plant and animal cells is that animal cells do not have (1)a nucleus (2)chloroplasts (3)a cell membrane (4)centrioles Which structure permits the entry and exit of materials in an animal cell? (1.) lysosome (2.) chromosome (3.) cell wall (4.) cell membrane The rigidity (support) of a plant cell is due primarily to the presence of the (1) chloroplasts (2) centrosomes (3) cell membrane (4) cell wall Which structure is found ONLY in animal cells? (1.) cell wall (2.) vacuoles (3.) centrioles (4.) chloroplasts Which sequence of terms is in the correct order from simplest to most complex? (1) cells, tissues, organs, organ systems (2) tissues, organisms, cells, organ systems (3) cells, tissues, organ systems, organs (4) organs, organisms, organ systems, cells C6H12O6 + 6O2 6CO2 + 6 H2O + X Aerobic respiration 1. Identify the process represented above. 2. Identify the raw materials. glucose and oxygen Mitochondria 3. Where does this process occur? 4. Identify the waste products. carbon dioxide and water 5. Identify molecule X. Energy or ATP 6. Describe the importance of this process. It provides energy that is needed for all cell activities. When muscles are exercised extensively in the absence of sufficient oxygen, (1) lactic acid is produced (2) a large amount of ATP is formed (3) NADH molecules split (4) oxidative respiration occurs Yeast produce alcohol and CO2 in the process of (1)lactic acid fermentation (2)alcoholic fermentation (3)aerobic respiration (4) glycolysis The net yield of ATP from the process of fermentation is (1.) 2 (2.) 4 (3.) 34 (4.) 36 1. What type of transport does this picture represent? Active transport 2. Explain your answer. Substances are moving from a LOW to HIGH concentration. Identify the type of transport represented in the diagram. Support your answer. Passive transport because materials are moving from a HIGH to LOW concentration. Identify the type of passive transport occurring in the diagrams if the particle moving is glucose. Support your answer. Diffusion because glucose is moving from a HIGH to LOW concentration. When does this process stop? When equilibrium is reached. (When there is an EQUAL concentration on both sides) 1. Identify structure A. Support your answer. Electron because it is negative. 2. Identify structure B. Support your answer. Proton because it is positive. 3. Identify structure C. Support your answers. B A C Neutron because it is neutral. It does not have a charge. 4. Identify the structure in the middle of the atom that contains protons and neutrons. Nucleus B A C 5. Identify the atomic number of this atom. Support your answer. Atomic number is 8 because the atom has 8 protons. Element or compound? Bc it is made up of 2 or 1. NaCl Compound more different elements. 2. O Element Bc it is made up of only one type of atom it is made up of 2 or 3. CO Compound Bc more different elements. 4. C6H12O6 Compound Bc it is made up of 2 or more different elements. 5. N Element Bc it is made up of only one type of atom Bc it is made up of 2 or 6. CO2 Compound more different elements. 7. H2O Compound Bc it is made up of 2 or more different elements. A chemical formula like CO2 represents 1. an element 2. an atom 2. an electron 4. a compound A substance made up of two or more elements that have been chemically combined is a COMPOUND. A substance made up of two or more elements that have been physcially combined is a MIXTURE. Explain why sand and water is not a solution. The sand did not dissolve in the water. The sand was not evenly distributed. Chromatography 1. Identify the method used to separate the mixture. Filtration (filter paper) 2. Identify the type of mixture being separated. Solid-liquid mixture 1. Identify the method used to separate the mixture. Magnet 2. Identify the type of mixture being separated. Mixture with iron filings Chromatography 1. Identify the method used to separate the mixture. Evaporation 2. Identify the type of mixture being separated. A solution Chromatography 1. Identify the method used to separate the mixture. A sieve 2. Identify the type of mixture being separated. Rocks and sand What do we know about the elements in the same group or family? They have the same (BUT NOT IDENTICAL) properties. Identify the solid, liquid and gas! Support your answer. Gas - Atoms are very loosely packed Solid Liquid - Atoms are tightly packed - Atoms are loosely packed Identify the phase change described. 1. Solid to liquid: melting 2. Gas to liquid: condensation 3. Liquid to solid: freezing 4. Solid to gas: sublimation 5. Liquid to gas: vaporization For each phase change describe whether energy is RELEASED or ABSORBED. 1. Melting: ABSORBED 2. Freezing: RELEASED 3. Vaporization: ABSORBED 4. Sublimation: ABSORBED 5. Condensation: RELEASED