Suppose you were in charge of sending an unmanned space probe to a new planet in search of life. The probe would be able to coll
ect and test samples and make observations, but the planet is too far away for the probe to be able to bring samples back to Earth. The probe is small and would only be able to run a few tests, so you want to pick a test for evidence of life that is broad enough to incorporate all forms of life as we know it. Which one of the following tests would be the best to use in this situation A. a test for the presence of large organisms capable of movement
B. a test for the presence of things that change size quickly, since it would be an indication of growth and development
C. a test for the presence of soil suitable for growing plants
D. a test for the presence of cells that contain DNA
Option D, a test for the presence of cells that contain DNA
Explanation:
As we know all living organisms are made up of cells and DNA is the basic genetic material that codes for protein and traits with an organism. If even a single cell with DNA is detected on the extraterrestrial planet then it will be clear that it has life on it or the environmental conditions are favorable to support life. Cells are microscopic and hence can be seen through microscope which can be installed easily on a probe.
