Final answer:
Streptococcus pneumoniae is the microorganism that is part of our normal flora and causes pneumonia and endocarditis.
Step-by-step explanation:
The microorganism that is part of our normal flora and causes pneumonia and endocarditis is Streptococcus pneumoniae. This gram-positive, alpha hemolytic streptococcus is commonly found as part of the normal microbiota of the human respiratory tract.