7 th GRADE LIFE SCIENCE REVIEW PACKET

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1 Name Period Date 7 th GRADE LIFE SCIENCE REVIEW PACKET PART 1. SCIENTIFIC METHOD I. STEPS 1. PROBLEM - always in the form of a _question 2. HYPOTHESIS - _an educated guess / possible answer to the problem_ 3. EXPERIMENT - 3 parts: Control, dependent variable, independent variable 4. OBSERVATIONS - analyze data, charts, graphs 5. CONCLUSION - is your hypothesis right or wrong? II. DEFINE THE FOLLOWING TERMS: 1. CONTROL = used as a comparison in the experiment_(does not get the independent variable)_ 2. INDEPENDENT VARIABLE = experimental factor 3. DEPENDENT VARIABLE = what is being measured in the experiment (ex: height of plant) 4. Example: A student set up the experiment shown to learn about plant growth. The student added a different amount of water to 4 identical containers, each containing 4 seeds in 100 cubic centimeters of soil. All of the containers were placed in the same sunny location. The height of the plants were measured and recorded for 5 weeks. a. State a hypothesis for this experiment. If more water is added to the plant it will increase growth of the plant. b. Independent variable = water c. Dependent variable = height of plant d. Identify the factors that must remain constant in this experiment. location, # of seeds, soil, type of seeds, container, etc 1 III. REVIEW QUESTIONS 1. The first step in the scientific method is a. state the hypothesis b. state the problem c. experiment d. observation 2. What is the factor in an experiment that remains constant?

2 2 a. control b. variable c. theory d. hypothesis 3. A student placed 10 radish seeds of the same variety on moist paper in each of three petri dishes and placed the dishes in the following environments: Dish 1: Refrigerator, 5 C Dish 2: Room Temperature, 20 C Dish 3: Incubator, 37 C Which factor is the independent variable in this investigation? a. temperature b. kind of seeds c. moisture d. number of seeds 4. Identify 2 safety rules that must be followed when performing a lab. PART 2. MEASUREMENT I. LENGTH meter 1. What is the length of the tadpole at the right? a. In centimeters= 3.1 cm b. In millimeters = 31 mm II. MASS - meters 1. What instrument is being used to measure the mass of the object at the right? triple beam balance 2. What is the mass of the object? 175 grams III. VOLUME - liters 1. Calculate the volume of the block below. Show all work in the work space below. V = LxWxH V = LxWxH V= 2.4cm x 4.2cm x5.3cm V= 53.4cm 3 2. What is the name of the instrument at the right? 4. What is the volume of rock below? graduated cylinder 3. What is the volume of the water? 16mL

3 3 IV. REVIEW QUESTIONS 1. What is the temperature shown in the thermometer 2. What is the length of the snail? 2.6cm shown below? 25 degrees C 4. Draw the staircase we use to convert from 1 metric unit to another. 3. What are the volumes of the 2 liquids shown below? a. 42mL b.13ml 5. Convert the following measurements: a cm = km b L = 546 ml 6. Which instrument would be used to obtain the volume of a glass of water? a. triple beam balance c. beaker b. graduated cylinder d. metric ruler 7. Which group of measurement units is correctly arranged in order of increasing size? a. millimeter, centimeter, meter, kilometer b. millimeter, kilometer, centimeter, meter c. meter, kilometer, centimeter, millimeter d. kilometer, centimeter, millimeter, meter 8. In the metric system, the height of a building would be given in a. centimeters b. milliliters c. meters d. millimeters 9. Which piece of equipment could be used to determine the mass of a frog? a. triple beam balance c. beaker b. graduated cylinder d. metric ruler 10. Mass is best defined as the a. size of an object c. density of an object b. amount of matter in an object d. weight of an object

4 4 PART 3. MICROSCOPE I. PARTS & FUNCTIONS: 1. eyepiece/ocular lens lens that you look 6. body tube connects objective & eyepiece through to magnify specimen 7. stage table that holds the slide 2. coarse adjustment knob focusing under 8. mirror/light source provides light to view low & medium powers (NOT HIGH POWER) specimen 3. fine adjustment knob focusing for high 9. base structure that supports microscope power, sharpening image (for carrying) 4. objective lens lenses that magnify specimen 10. diaphragm openings that controls the amount low = 4x medium = 10x high = 40x of light used (under stage) 5. arm supports body tube (for carrying) II. LABEL THE PARTS OF THE MICROSCOPE BELOW. A. eyepiece/ocular lens A B. bodytube I J H B C D E F G C. _objective lens D. stage E. _diaphragm F. mirror/ lightsource G. base H. coarse adjustment I. fine adjustment J. arm III. USING THE MICROSCOPE 1. What would happen if you used the coarse adjustment under high power? Could crack the lens or slide 2. When you observe a specimen using a microscope, how does the specimen appear? _upside down and backwards 3. When you move the slide in any direction, how does the specimen on the slide appear to move? opposite direction you are moving it 4. Which objective lens allows you to observe LARGER field of view? low power

5 5 5. Calculate the total magnification: a. Eyepiece lens = 15x, Objective lens = 5x Total Mag = 75x b. Eyepiece lens = 10x, Objective lens = 10x Total Mag = 100x c. Eyepiece lens = 20x, Objective lens = 40x Total Mag = 800x 6. What is the student in the picture at the right preparing? wet mount 7. Why should the student make sure the cover slip is lowered at an angle? _decrease air bubbles IV. MEASURING WITH THE MICROSCOPE 1. What is the diameter of the field of 2. What is the length of one of the cells shown below? 4.3mm = 4300um view shown below? 500um 3. Determine the lengths of the objects in the microscopes field of view below. a. 800um b. 500um 4. How many micrometers make up one millimeter? 1000um