 |
Introduction to Cell & Molecular Biology (BIOL121) - Dr. S.G. Saupe (ssaupe@csbsju.edu); Biology Department, College of St. Benedict/St. John's University, Collegeville, MN 56321 |
|
Introduction to Cell & Molecular Biology (BIOL121) - Dr. S.G. Saupe (ssaupe@csbsju.edu); Biology Department, College of St. Benedict/St. John's University, Collegeville, MN 56321 |
Photosynthesis � Classic Experiments
Jean Baptista van
Helmont (1577 � 1644)
van Helmont performed an experiment in which he placed a
willow seedling in a sealed pot. He watered the plant regularly. The plant
weighed five pounds at the beginning of the experiment and 169 pounds at the
conclusion of the experiment five years later. The primary source of the
increased weight (mass) of the plant is from:
a.
the water he added
b. minerals that were present in the soil
c. carbon dioxide in the air
Joseph Priestly (1733 �
1804)
Priestly was a Unitarian minister and chemist. He did the
following experiments:
Summary:
burning candle + bell jar
mouse + bell jar → dead mouse
mouse + bell jar + add a mint plant → mouse lives
Questions:
Why did the candle burn out when placed under bell jar?
Why could the candle be relit after allowing it growth with a mint plant?
Why does a mouse die when it is placed under a bell jar?
Why was the mouse able to survive when placed in the jar with a mint plant?
Assuming a supply of water was available to both mint plant and mouse; could the mouse and plant survive indefinitely under the jar? Explain.
Last updated: July 14, 2009 � Copyright by SG Saupe