question below:
Researchers recently discovered a gene in humans that previously was unknown to science. Which statement best explains why the gene probably was not discovered much sooner?
answer below:
The technology used to study genes is still being developed.

question below:
Data indicate that chemical pollutants contaminate 53% of the waterways that empty into the Chesapeake Bay. These chemical pollutants are found in the tissues of animals living in the bay. Which group of people who live away from the bay might be most affected by these chemical pollutants?
answer below:
people who consume fish from the bay

question below:
In addition to oxygen, which gases make up the largest percentage of Earth's atmosphere?
answer below:
carbon dioxide, water vapor, and nitrogen

question below:
Which adaptation will warn predators not to eat an animal?
answer below:
bright colors