Questions

We know that, preceeded means to come before. 

Hence, the given sentence, preceded in death means that person had died before this person.

For example :: Rahul preceeded Ravi in death, means Rahul died before Ravi.

Gitanjali Rao, an 11-year-old Indian-American schoolgirl, was named as "America’s top young scientist" for inventing a cost-effective, quick lead-contamination detector in water. The seventh-grade student was inspired by the large-scale lead contamination in water in Flint, Michigan, that came to light recently.

The olfactory system is the only system in which the receptors send their signal directly to the higher brain and bypass the thalamus, which normally acts as a filter for the processes of the lower brain.

Peru is a country in South America. Lima is the capital city of Peru. Sol is the currency of Peru.

Gene flow means migration of genes from one to another. This gene flow is caused by individuals moving into population.