In 1900, 4 percent of the u. s. population was aged 65 or older. that figure was 12.4 percent in 2000, and it is estimated that it will be 20.2 percent in 2050. which phrase refers to this change? a. the "american dream" b. the "graying of america" c. the "american melting pot" d. the "manifest destiny of america"

The chart below matches messenger rna codons with amino acids. a dna strand has the sequence of bases, aat. according to the chart, the corresponding messenger rna codes for which amino acid?

Explain how earth is like a giant bar magnet. how is our magnetic field made?

In an ecosystem, marsh snails feed on phytoplankton and painted turtles feed on marsh snails. pollution has resulted in the depletion of phytoplankton. what effect would this situation likely have on the population of marsh snails and painted turtles? as phytoplankton were destroyed, the population of marsh snails would most likely then the population of painted turtles would mostly likely a. 1. increase 2. decrease 3. stay the same b. 1. increase 2. decrease 3. stay the same