Transcript Science 7
Science 7 Review From Last Class Did you….? Finish your Twizzler lab/conclusion questions? Put a name on it? Put it in the Pass In bin? Quizzes (Hand Back) Brainpop-Scientific Method https://www.brainpop.com/science/scientif icinquiry/scientificmethod/ Hypothesis A hypothesis is: an educated guess or proposition that attempts to explain a set of facts or phenomenon. Hypothesis A hypothesis should always: Explain what you expect to happen Be clear and understandable Be testable Be measurable Contain an independent and dependent variable Ex: Tim and Moby stated their hypothesis as “Fig plants do best if you only water them once a week” Hypothesis It is usually written in the form: If__________ then ________ will happen because___________________________. Based on our observations, inferences and background knowledge we can make a TESTABLE hypothesis Hypothesis: from Inference to Testable Statement Observation/inference: Chocolate may cause acne. From this we can write a testable hypothesis: If chocolate consumption is related to acne, then the frequency of acne will be higher when people consume large amounts of chocolate (5 or more bars per day) than when subjects consume little or no chocolate. Hypothesis: from Inference to Testable Statement Observation/Inference: Eating breakfast improves performance in school. Hypothesis: IF students eat breakfast before school, THEN test scores for those students should improve from nonbreakfast eating test scores. Practice: Writing a Hypothesis 1. 2. 3. 4. 5. Observations Salt in soil may affect plant growth. Temperature may cause leaves to change color. Sunlight causes fruit to ripen more quickly. Bacterial growth is affected by temperature Ultraviolet light may cause skin cancer. Hypotheses 1. _________________ 2. _________________ 3. _________________ 4. _________________ 5. _________________ Practice: Writing a Hypothesis Observations 1. 1. Salt in soil may affect plant growth. 1. 1. Temperature may cause leaves to change color. 1. 1. Sunlight causes fruit to ripen more quickly. 1. 1. Bacterial growth is affected by temperature. 1. 1. Ultraviolet light may cause skin cancer. Hypotheses If salt in soil affects plant growth, then plants grown in higher salt content soil will grow slower than low salt content soil. If temperature causes leaves to change color, then plants exposed to cooler temperatures (less than 15°C) should change color faster than plants exposed to warmer temperatures (above 15°C) If sunlight causes fruit to ripen more quickly, then fruit kept in the dark should ripen slower than fruit kept in direct sunlight. If bacterial growth is affected by temperature, than food kept at a lower temperature (below 4°C) should have less bacterial growth than food kept at room temperature. (above 4°C) If ultraviolet light causes skin cancer, then rates of skin cancer occurrence will be higher in people exposed to higher amounts of UV light (ie: tanning bed users, not using sunscreen). Hypothesis- Points to Consider Does it have a measurable prediction that we can test? Avoid phrases like: better than, bigger than, a little more than (Need to be measurable/objective) Practice- Worksheet Using the problem and observations given, create a hypothesis to explain what’s happening. Describe how you might test your theory If the page given doesn’t provide enough space please feel free to use the back side or looseleaf When completed- name and put in Pass In Bin