Combine the given two facts to write a concluding fact. Note that there should be some parts of the first and second facts that are not mentioned in this conclusion fact. Your combined fact should be the result of a chain between the two facts. Chains form when two facts connect together to produce a concluding fact. An example of a chain is: "pesticides cause pollution" (fact1) + "pollution can harm animals" (fact2) → "pesticides can harm animals" (conclusion fact). Parts of the concluding fact overlap with the first and the second fact. To construct such a  concluding fact, a useful way is to borrow the subject from one fact and the ending conclusions from another fact.

Fact 1: Introns are regions that do not code for proteins. 
Fact 2: Introns are found in eukaryotes.
eukaryotes have regions that do not code for proteins.

Fact 1: a flashlight requires a source of electricity to produce light. 
Fact 2: Light contains energy.
A flashlight requires a source of electricity to produce visible energy.

Fact 1: Birth may be followed by a period of parental care of the offspring. 
Fact 2: Human birth is the rarest of all births.

humans have a period of parental care of their offspring.