Nhận biết (M1)

Just like household dust on Earth, dust on the International Space Station (ISS) harbors hundreds of common microorganisms—Aspergillus sydowii and other fungi, along with bacteria, such as Corynebacterium kroppenstedtii. According to experiments conducted using samples of ISS dust of initially similar compositions, changes in both relative humidity (RH) and duration of humidity exposure elicited changes in growth for both fungal and bacterial species. However, when overall fungal growth increased, it was mainly due to an increase in growth of A. sydowii, whereas bacterial growth was widely distributed across species in the samples.

Taken together, information in the text and table best support which statement about the ISS dust samples following the conclusion of the experiment?

• A.

  The sample at 85% RH for 12 hours/day contained a lower proportion of A. sydowii than the sample at 100% RH for 24 hours/day did.

• B.

  The sample at 100% RH for 24 hours/day contained the highest proportion of fungi among the three samples.

• C.

  The sample at 85% RH for 12 hours/day contained a lower proportion of C. kroppenstedtii than the sample at 100% RH for 24 hours/day did.

• D.

  The sample at 100% RH for 24 hours/day contained a higher proportion of fungi than bacteria.