5.1.1 The Unraveling of Photosynthesis: A Historical Perspective Flashcards
1
Q
experiments by Van Helmont, Joseph Priestly, and Ingenhousz
A
- helped to pave the way for the unraveling of photosynthesis.
• Photosynthesis is the process by which plants produce their own food.
2
Q
autotrophs
A
- organisms that can synthesize their own food
3
Q
heterotrophs
A
- organisms that must take in food from outside sources
4
Q
Van Helmont
A
- In the seventeenth century Van Helmont planted a willow tree in a tub. After five years he calculated that the willow tree gained 164 pounds. He also calculated that the soil had lost two ounces.
- From his research, Van Helmont concluded that water was involved in the conversion of abiotic (H2O) material to biotic materials (plant tissues).
5
Q
Joseph Priestly
A
- was a clergyman who performed photosynthesis experiments. He placed a mouse in a lidded empty jar. The mouse died because there was no oxygen available. When a mouse was placed in a jar with a plant, it lived.
- From is experiment, he concluded that plants must be able to produce oxygen; thus plants are able to take in water and form organic materials and oxygen.
6
Q
Ingenhousz
A
- found that plants give off oxygen in the presence
of light. He also found that in the dark, plants give off some carbon dioxide (CO2). - Plants must therefore somehow use water and light to build plant material and give off oxygen.
7
Q
True or false?
Plants are heterotrophs, because they rely on water, light, and carbon dioxide for food.
A
- false
8
Q
Who found that plants give off oxygen in the presence of light and give off some carbon dioxide in the dark?
A
- Jan Ingenhousz
9
Q
Johann Baptista van Helmont concluded that the willow tree gained its weight from
A
- water
10
Q
Joseph Priestly discovered that
A
- the gas that a mouse removes from the air is produced by plants
