Think-Pair-Share Questions

1. A strain of living Streptococcus pneumoniae that cannot make a capsule is injected into mice and has no adverse effect. This strain is then mixed with a culture of heat-killed Streptococcus pneumoniae that when alive was able to make a capsule and kill mice. After a period of time, this mixture is injected into mice and kills them. In terms of horizontal gene transfer, describe what might account for this.

2. A gram-negative bacterium that was susceptible to most common antibiotics suddenly becomes resistant to several of them. It also appears to be spreading this resistance to others of its kind. Describe the mechanism that most likely accounts for this.