Standard 5: Students will understand that microorganisms range from simple to complex, are found almost everywhere, and are both helpful and harmful.

Name Grade 6 Standard 5: Students will understand that microorganisms range from simple to complex, are found almost everywhere, and are both helpful and harmful. Objective 2: Demonstrate the skills needed to plan and conduct an experiment to determine a microorganism s requirements in a specific environment. Use the following diagram to answer question 1. 1. A 6 th grade class observed the growth of a bacteria colony. Measurements were taken of the diameter of the colony. What would be the projected size of the colony on Day 4? A. 10 mm B. 11 mm C. 12 mm D. 13 mm 1

2. What is an appropriate title for the vertical numbers listed? Growth of Bacteria Colony 12 10 8? 6 4 2 0 1 2 3 4 Days of Bacteria Growth A. Requirement for bacteria growth B. Types of bacteria C. Millimeters of bacteria growth D. Days of bacteria growth 3. A student collected pond water samples in January and again in July. The water was examined under a microscope. What conclusion would the student most likely make? A. more microbes would be observed in January B. more microbes would be observed in July C. few microbes would be observed in July D. the approximate number of microbes would never change 4. The diagrams below show an experiment with two pieces of bread that had a small area of mold on them. Which conclusion is most likely? A. Without the zip-lock bag, the mold area in Bread 1 and 2 would probably be the same on Day 14. B. The mold area in Bread 1 would probably be larger on Day 14 if the experiment is repeated. C. The mold area in Bread 2 would probably be larger on Day 14 without the zip-lock bag. D. The mold areas in Bread 1 and 2 would disappear if they were both in zip-lock bags. 2

5. A student used 20 of his classmates to do an experiment on the best way to wash your hands. He put 5 students in each group that he studied. After 24 hours he carefully recorded his data in the following table: 5 students Number of samples that grew bacteria washed hands in cold water washed hands in warm water washed hands using soap in warm water didn t wash hands 5 4 0 5 Which statement below is the best conclusion? A. Washing has no effect on the removal of bacteria from your hands. B. Washing in cold water is as effective as any other kind of washing. C. Washing in warm water is the most effective method of washing. D. Using soap and warm water is the most effective method of removing bacteria. 6. A scientist wonders if a certain bacteria can survive being frozen. Which of the following is a correctly written hypothesis? A. If bacteria are frozen, then they will die. B. Bacteria are small, microscopic life forms. C. The bacteria died when it was frozen. D. Bacteria survive best when they are moist. The foods listed on this data table were left in plastic bags in a warm container for 5 days. Observations were made and recorded at the end of the experiment. Use this information to answer the next two questions. Bread Banana Hamburger Cheese Food Observations after 5 Days Covered with black, fuzzy mold Slimy, black, turning to liquid Turned brown, smelly Has white and green coating 7. What variable was tested in this experiment? A. the length of time it takes for food to rot B. what kind of bags allow rotting to occur C. the temperature microorganisms like best D. how different kinds of food rot 3

8. Which of these hypotheses might have been tested in this experiment? A. If foods are left in the dark they will rot differently than foods in the light. B. Will foods react differently in plastic bags? C. If different foods decay then different effects will be evident. D. What kind of bacteria is best for making cheese? 9. Which of these questions can be answered only by making observations (without planning and conducting an experiment)? A. What is the effect of sugar on the growth of yeast? B. What are three ways that protozoa move? C. Does antibacterial soap really affect the growth of bacteria? D. How does temperature affect the growth of bread mold? 4

Use the following data to answer questions 10 and 11. The 6 th grade students were each given an assignment to prepare an experiment on microorganisms at home that they could share with the class. Part of their assignment was to write about their experiment and what they learned. Here are a few examples: 1. Mary grew mold on potato slices in four different temperatures. She carefully recorded her data, took pictures of the growth, and wrote a complete conclusion. 2. Scott grew fungi on bread; he tested the effects of the amount of moisture on the growth of fungi. He explained to the class what he had learned with the help of a graph. 3. Leslie wanted to test different foods to see which one would grow fungi best. She wrote a hypothesis before she started. She carefully monitored her project and recorded the data. She understood and explained to the class which food had worked best. 4. Candace wanted her project to test whether fungi would grow better in a dark area, or in a light area. She used the scientific method and shared her findings with her class. 10. What question are they trying to answer? A. Will mold or fungi grow on potatoes? B. What are microorganism s requirements for survival? C. What is the best food for mold to grow? D. What needs to be done to do these experiments at home? 11. How did these students learn about microorganisms? A. by experimenting B. attending a field trip C. on the internet D. correspondence with a scientist 5

12. What line graph matches the data given in the table below? Bacteria Growth Growth 8 mm F 10 mm F 12 mm F 14 mm F A B C D 6

Grade 6 Standard 5 Objective 2 Answer Key 1. C 2. C 3. B 4. A 5. D 6. A 7. D 8. C 9. B 10. B 11. A 12. B 7