A police car passes a pedestrian with its siren on. A change in the siren's pitch is

A sample of biological origin was analyzed for its elemental composition and found to contain only carbon and hydrogen. Which type of macromolecule might it be?

Most populations on earth are affected by several factors such as a genetic drift mutations and natural selection which statement applies to a population that is experiencing changes in gene frequencies Evolution is occurring in the population

Mrs. Humphries has a small garden. She planted tomatoes, zuccinni, onion, garlic and beans (legumes). When summer is over and she harvested her crops, why did Mrs.

What have living things enclosed from?

The kingdom, Protista, includes A) most viral agents. B) prokaryotic organisms. C) yeasts and bread molds. Eliminate D) most single-celled eukaryotes.

3. In which process do substances have to be in direct contact when heat moves from areas of more heat to areas of less heat?

While on an archaeology expedition, you unearth a skeleton with the following characteristics: four long, slender finger bones and a smaller opposable thumb bone, long arm bones, fingernails, and eye sockets close together on a skull.

Describe respiration

Which of the following is a property of minerals? a. Age b. Odor c. Hardness d. Size

What created the abundant agriculture in the Napa Valley of California? A:oceanic-continental convergence B: an earthquake C: a tsunami D:continental-continental convergence