Chapter 1: Science of Biology

Practice Identifying Parts of the Scientific Method

Experimental Scenario #1: Problem/Observation: Ants digging tunnels in different light conditions

Question: Does tunnel digging activity depend on light conditions?

Hypothesis: Ants will dig more tunnels during the daytime.

Experiment:

Independent variable: Amount of light ants were exposed to

Dependent variable: Level of tunnel digging activity

Controls: Type of ants, number of ants, amount of food, and temperature

Control Group: There was no control in this experiment (flaw?)

Experimental groups: 5 colonies in normal room light and 5 colonies covered in construction paper

Construct a line graph, shows tunnel length over the course of the study. Graph should have two lines. X axis should be # of days and Y axis should be length of tunnels for light group and dark group. Label each axis and include units, graph should have a title.

Experimental Scenario #2: Problem/Observation: effect of radiation on seeds

Question: Will radiation impact the ability of a seed to germinate?

Hypothesis: Exposure to microwave radiation will impact the ability of a seed to germinate.

Experiment:

Independent variable: Amount of radiation

Dependent variable: whether or not seeds germinate after exposure to radiation Controls: same flats, water, temperature, same type of seeds?

Control Group: Seeds receiving no radiation.

Experimental groups: seeds that received 3 seconds and 6 seconds of radiation.

Construct a bar graph, radiation on X axis, number of seeds germinated on Y axis. Be sure to label axis and include units. Graph should have a title.

Experimental Scenario #3: Problem/Observation: effect of aged-grass compost on plant growth

Question: Will compost make plants grow faster?

Hypothesis: Aged-grass compost will increase the growth rate of bean plants.

Experiment:

Independent variable: Age of compost

Dependent variable: Plant height (growth)

Controls: water and light

Control Group: flat receiving no compost.

Experimental groups: flats that received 3 month and 6 month old compost.

Construct a bar graph using the average plant height for the 3 conditions or a scatter plot, showing the distribution of heights within each compost group. Be sure to label each axis and include units. Graphs should also have a title.