Question

situations: read the situation below and design an experiment.
a: john smith has been hired by the city of virginia beach to investigate the recent shark attacks off the resorts coast. he has a budget of $40,000, a 25 foot boat, and three graduate student assistants to help him. a helicopter has also been donated by a local television station, should he need one.

1. list 2 hypotheses john and his crew may have come up with for the recent shark attacks.

a. if__________________________, then__________________________
b. if__________________________, then__________________________

1. pick one of the two hypotheses and determine the following:

a. control group: time of year when elephant seals are not present or another area with no elephant seals
b. experimental group: times/areas when/where elephant seals vary
c. dependent variable:____________________________
d. independent variable:____________________________

1. what type of data do you think john will collect (what will be the results of the experiment)?
2. what conclusions will john be able to make from the results of the experiment?

b: suzie q wants to know the effect of different colors of light on the growth of plants. she believes that plants can survive best in white light. she buys 5 ferns of the same species, which are all approximately the same age and height. she places one in white light, one in blue light, one in green light, one in red light and one in the closet. all of the ferns are planted in miracle - grow and given 20 ml of water once a day for 2 weeks. after the two weeks, suzie observes the plants and makes measurements.
hypothesis: if plant growth is affected by color of light, then white light will produce the most plant growth.
independent variable:
dependent variable:
control group:
experimental group:
what could be the controlled variables?
what types of measurements can suzie make on the plants to determine how they did in different types of li

Explanation:

• Independent Variable: The factor that is changed or manipulated in an experiment. In Suzie's experiment, the color of light is what she is changing (white, blue, green, red, and no light - closet).
• Dependent Variable: The factor that is measured and is affected by the independent variable. Here, it is plant growth (which can be measured by height, number of leaves, etc.).
• Control Group: The group that serves as a baseline for comparison. The fern in the closet (no light) can be considered a control as it is not exposed to the colored lights (a more traditional control might be the white - light plant if we assume natural light is similar to white light in some contexts, but based on the setup, the closet - plant is a non - light control).
• Experimental Group: The groups that receive the treatment (the independent variable manipulation). The ferns under blue, green, red, and white light (if we consider white light as a test of a particular light color hypothesis) are the experimental groups.
• Controlled Variables: These are factors that are kept the same to ensure a fair experiment. The species of fern (all same species), age (approximately the same age), height (approximately the same height at the start), planting medium (Miracle - Gro), water amount (20 mL per day), and duration of the experiment (2 weeks) are all controlled variables.
• Measurements: Suzie can measure the height of the ferns, the number of new leaves, the overall health (e.g., color of leaves - if they are yellowing or not, which can indicate growth issues), and the length of the roots (by carefully removing them from the planting medium).

Answer:

• Independent Variable: Color of light
• Dependent Variable: Plant growth
• Control Group: Fern in the closet
• Experimental Group: Ferns under white, blue, green, and red light
• Controlled Variables: Species of fern, age of fern, height of fern at start, planting medium (Miracle - Gro), water amount (20 mL/day), experiment duration (2 weeks)
• Measurements: Height of ferns, number of new leaves, leaf color (as an indicator of health), root length