Question

1. Plants carry out chemical reactions that make sugars, which contain carbon, hydrogen, and oxygen, from carbon dioxide (CO2) and water (H2O). Researchers want to know whether the oxygen atoms in sugar come from the carbon dioxide or the water. How could they use radioactive tracers to find out? Design an experiment that investigates this question. Be sure to include the following elements in your experimental design: hypothesis, procedure, control group, experimental group.

Answer 1

Radioactive labeling is a procedure used to monitor the path followed by a chemical element within a biological system to demonstrate the source.

Hypothesis:

The free oxygen produced during photosynthesis comes from water.

Procedure.

Single-celled algae were placed in four petri dishes containing carbon dioxide, glucose dissolved in Water.

In each box the oxygen was radioactively marked.

1 petri dish with CO2 marked. Experimental groups

2 petri dish with H2O marked. Experimental groups

3 petri dish with Glucose marked. Experimental groups (control)

4 petri dish with CO2 + H2O + Glucose, all marked. (control).