Question

from her study participants:
which of the following statements apply to this study and its results?
correct answer(s)
antibiotic use reduced species richness in the bacterial community.
the bacteria in the study participants guts represent ecological communities.
the composition of species in the community changed after antibiotic use.
species abundance increased as a result of antibiotic use.

Explanation:

• Antibiotic use reduced species richness in the bacterial community: Species richness is the number of species in a community. Pre - antibiotic total species = 20, post - antibiotic total species = 5. A decrease from 20 to 5 shows a reduction in species richness.
• The bacteria in the study participants’ guts represent ecological communities: An ecological community is a group of different species living together and interacting. The gut bacteria (different genera and species) form a community as they co - exist in the gut environment.
• The composition of species in the community changed after antibiotic use: Before antibiotics, there were species from Bacterioides (3 species), Clostridium (2 species), Eubacterium (5 species), Peptococcus (4 species), Bifidobacterium (6 species). After antibiotics, Bacterioides has 1 species, Clostridium 0, Eubacterium 2, Peptococcus 0, Bifidobacterium 1. The types and numbers of species (composition) have clearly changed.
• Species abundance increased as a result of antibiotic use: This is incorrect. Abundance would refer to the number of individuals of a species. But the data given is about the number of species (richness), not the number of individuals. And from the total species count (20 to 5), it's a decrease in the number of species (not an increase in abundance).

Answer:

Antibiotic use reduced species richness in the bacterial community, The bacteria in the study participants’ guts represent ecological communities, The composition of species in the community changed after antibiotic use.