Anaerobic photoautotrophs were the first organisms to release oxygen into the early atmosphere.

a. True

b. False

Movement of food from the stomach into the esophagus is usually prevented by

Which rock cannot be found as a chemical sedimentary rock? A. chert B. limestone C. sandstone D. rock gypsum

Some flowering plants appear to have offspring that have traits that are intermediate between those of the parents. Which type of dominance is exhibited by the offspring? complete dominance blended dominance codominance incomplete dominance

Definition: this is the process of organisms adapting to their environments over time.

How does the appearance of spongy bone differ from compact bone?

By what process do all living organisms grow and repair themselves?

What is the name of the heart's contraction?

Which describes the habitat of a frog?

The size of a population refers to the

An electric current will always follow a. the path of least resistance. b. a path toward the north pole. c. a path toward the south pole. d. the path that leads through insulators.