Question

In this scenario, the "organisms" most closely resemble a(n) what?

Suppose that a meteorite crashes into Earth and a sample of it is taken to a local research lab for analysis. Embedded several inches within the rocky structure, a microscopic cluster of dormant, spore-like structures is found. The scientists culture some of this material in a standard microbiological nutrient broth, and they are surprised to find many single-celled "organisms" moving around, growing, and reproducing in the broth. The "organisms" behave the same in both daylight and dark conditions, do not require oxygen, and persist under a wide range of temperatures and pH levels. They stop moving, growing, and reproducing, however, when fewer nutrients are available in the medium.

In this scenario, the "organisms" most closely resemble a(n):

A.) heterotrophic species of Archaea.

B.) autotrophic species of Eukarya.

C.) nonliving virus.

D.) heterotrophic species of Eukarya.

E.) photosynthetic species of Bacteria.

Answer

A

1) It has to be heterotrophic, as it requires a food source, and is unable to make its own food as demonstrated by having same growth rates in daylight and dark

2) It has to be Archaea, because all members of Eukarya are obligate aerobes, so they must have oxygen to survive

3) Further evidence of Archaea: "wide range of temperatures and pH levels"

Archaea are known for their versatility and proliferation in surprisingly hostile environments, and have been given names to demonstrate that. For example, thermoacidophiles love boiling conditions of geysers, and can be found in the volcanically active Yellowstone National Park.

Sep 9 at 1:29