This bacterium derives nutrition by digesting human intestinal contents (in other words, food). humans lacking this bacterium have no measurable reproductive advantage or disadvantage relative to humans who harbor this bacterium. consequently, the bacterium can be properly described as which of the following? 1. symbiont 2. endotoxin 3. mutualist 4. commensal
1 and 2
4 only
2 and 3
2 and 4
1 and 4

Select all the correct answers. for a claim about the natural world to be considered scientific, what attributes must it have? a). it must be open to modification if new evidence doesn't completely support it. b). it must be based on scientific observations that can be repeated in a controlled setting. c). it must be applicable to future events and occurrences. d). it must be consistent with only a small portion of relevant observations or data.