Spina bifida and anencephaly are examples of neural tube defects. women who have had a pregnancy resulting in the birth of an infant with a neural tube defect are being urged to take supplements of before a second conception to decrease the risk of these birth defects. a. vitamin b-12 b. folic acid c. iron and zinc d. extra dietary protein

What are two ways that harvesting algae from the ocean may benefit human society? how might the harvest of algae negatively impact the ocean communities where that algae grows? how could this be prevented?

Which of the following statements best distinguishes a hypothesis from a theory? a. theories are hypotheses that have been proved. b.hypotheses are guesses; theories are correct answers c. hypotheses usually are relatively narrow in scope; theories have broad explanatory power. d. theories are proved to be true; hypotheses are often contradicted by experimental results.

Scientists discovered fossils in several layers of the earth you see here. they found fossils of algae, snails, and clams in layer d. given that information, where do you think they found fossil evidence of simple land plants and amphibians? a. a b. e c. f d. g