AH Biology Homework 1

Two students, Carmen and George, determined the mass of an object on two different balances. The accepted mass of the object was 2.355 g. George obtained values of 2.531 g, 2.537 g, 2.535 g and 2.533 g. Carmen obtained values of 2.350 g, 2.404 g, 2.296 g and 2.370 g. Which statement best describes the results that were obtained by George and Carmen?

• George's results were more accurate that Carmen's.
• Carmen's results were less accurate than George's.
• George obtained the better precision.
• Carmen obtained the better precision.

Students did an experiment to determine if a substance contained glucose. To determine if glucose was present, they added 5 mL of Benedict's solution to a test tube of corn syrup and then heated the mixture. A change to a brick red color was a positive indicator for glucose. Which piece of equipment provides the most precise measurement of the volume of the Benedict's solution?

• A - Test tube
• B - Graduated Cylinder
• C - Beaker
• D - Erlenmeyer flask

A student observed a plant near a window growing toward the window. The student hypothesized that environmental conditions affect the growth of plants. The table shows the student's protocol for an investigation.

• A. Develop a conclusion
• B. Investigate multiple variables
• Repeat the controlled investigation
• Compare the results with a published work.

Students compare the size of bacterial colonies grown on two different agar plates. The illustration below shows colonies grown on Agar Plate 1 and Agar Plate 2. Which ruler would most accurately measure the diamter of the colonies on Agar Plate 1 and Agar Plate 2?

• a ruler that measures to the nearest millimeter.
• a ruler that measures to the nearest centimeter
• a ruler that measures to the nearest decimeter
• a ruler that measures to the nearest meter

At the beginning of an experiment, students measured the height of a plant three times. Their measurements are shown in the table below. It was determined that the actual height of the plant was 16.9 cm. Which student's measurements are the most accurate and precise to the actual height of the plant?

• Student 1
• Student 2
• Student 3
• Student 4

Students counted the population of trees in a forest to determine the numbers of four species. The actual number of trees in the forest area and each student's count are in the table. Which student had the most accurate count of tree species?

• Student 1
• Student 2
• Student 3
• Student 4

A student wants to be sure the triple beam balance she uses is accurate and precise. She checks the measurement of four different balances using a 5.0 gram mass. The results are shown in the table below. Which balance should the student use to collect the most accurate and precise data?

• Balance 1
• Balance 2
• Balance 3
• Balance 4

When conducting a scientific investigation, what should be done after a testable hypothesis has been established?

• Research the information used to form the hypothesis.
• Perform the experiments designed to test the hypothesis.
• Compare the hypothesis with the hypotheses of other scientists.
• Report the results of the observations that led to the hypothesis.

Students monitoring a pond ecosystem collect rain in several rain gauges positioned around the pond. The students measure the volume of water collected in each gauge after a storm to document the amount of rainfall the ecosystem receives. Which tool would be best to use to accurately measure the amount of water collected in each rain gauge?

• petri dish
• glass beaker
• medicine dropper
• graduated cylinder

Students are performing an experiment to study how colored light affects the rate of photosynthesis in plants. Which laboratory tool would be most useful in this experiment?

• pH meter
• Oxygen sensor
• Carbon sensor
• Digital thermometer