Is It Alive?Unknown #2

Chris, Isabelle, Max and Perla

What questions did we try and answer?

1. Is it made of one or more cells?

2. Does it adapt to different environments?

3. Does it convert energy?

4. Does it grow and develop?

5. (Does it reproduce?)

What did we do to investigate the answers to

your questions?

1. We looked at it under the microscope and compared it to other pictures of cells.

2. We put the sample into different environments and then observed any changes in size, shape, color, movement, and growth.

3. We put food (sugar) with the Unknown to see if it produced carbon dioxide and then placed it into bromothymol blue to see if it changed from blue to green or yellow.

4. We measured the growth and development of the Unknown in different environments.

The Environments That We Used To Stimulate Growth and The Organisms We

Expected To Thrive In ThemEnvironments to stimulate growth: Organisms expected to thrive in each

environment:

Soil Plant

Wet Paper Towel Plant

Sugar Water Bacteria, animal, microorganism, algae

Salt Water Bacteria, animal, microorganism, algae

Room Temperature Water Algae, microorganism

Warm Temperature Animal from an egg, algae

Room Temperature Control/Used to measure the Unknown’s response

Cold Water Used to measure the Unknown’s response

Results

Does It Have Cells?

Characteristics To Determine Whether Or Not It Has Cells:•We looked at other pictures of cells under the microscope and compared them to our unknown under the microscope•We looked for key parts of cells:

•Nucleus- dark spot inside the cell•Cell walls- darker area surrounding the cell

Bromothymol Blue Experiment Results

Tools That We Learned How To Use:

• Microscope

• Hot Plate

• Bromothymol Blue

• Computers In The Lab

Evidence Of Reproduction:

• We did not find any evidence of reproduction.

• Firstly we looked for any other signs that it was alive and when we determined that it was not alive (because it didn’t have cells, convert energy, respond to stimuli or grow and develop) we assumed that it also couldn’t reproduce.

Independent Variables, Dependent Variables and Controls

• Independent Variables: different environments (addition of sugar and salt to water, addition of soil and the wet paper towel, temperatures of the water)

• Dependent Variables: responses of the Unknown to the environments

• Controls: room temperature water with no additives, room temperature unknown with no additives

Final Answer: Is It Alive?

• No, Unknown #2 is not alive.

• Reasons: None of the 4 characteristics of life appeared in the sample. (We could not test the 5th characteristic.)

• It lacked cells. We knew this because, under the microscope it did not have any of the characteristics of cells.

• It did not grow or develop in the environments. We knew this because we made observations in a number of environments that would have supported many types of life and there were no signs of any growth.

• It did not convert energy because it didn’t excrete carbon dioxide and change the color of the bromothymol blue.

• It did not respond to the stimuli (extreme temperatures and different environments).

Information That We Learned That Helped Us Make Our Conclusion

• How To Use The Microscope

• What Bromothymol Blue is and how to use it to prove energy conversion

• Characteristics of Cells

• All living organisms excrete CO2

• Organisms’ Reactions to extreme temperatures

• Different environments that promote growth of organisms

Unanswered Questions:

• How can you prove that something can/can’t reproduce?

Bibliography

• Biology by McDougal Littell and Stephen Nowicki pages: R8-R9

• http://chem.lapeer.org/Bio1Docs/PhotoLab.html

• http://www.prsd.k12.ca.us/classrooms/Student_links/7th_sci_resource/microscopes_cells/7_cells_rescource.html

• Various Pictures from THE INTERNET