Salt marshes, such as the one on the Cape Hatteras National Seashore in North Carolina, have a salinity that ranges from 18 to 30 ppt. Where does the salt come from?

A. Salt-tolerant grasses

B. Migratory birds

C. Ocean tides

D. Human intervention

Which of these is a function of testosterone in reproduction? A. Increasing the growth and development of breast tissue B. Decreasing the temperature of the testes C. Promoting the production of sperm D. Causing the development of adrenal glands

Why is soil important to plants? a. It provides them with nutrients. b. It provides them with water. c. It provides them with a medium for growth. d. All of the abov

Which tree harvesting method promotes the growth of younger trees by selectively cutting mature trees over a period of 10 years?

Which technique is used to separate protein fragments based on size? polyacrylamide gel electrophoresis Southern blot agarose gel electrophoresis polymerase chain reaction

Compare the positions of the sun, moon, and the earth in a solar and lunar eclipse. Enter your answer in the space provided.

What things could cause an increase in a population? (Choose ALL of the correct answers.) Immigration Emigration Increased birth rate Increased death rate A decrease in limiting factors

For each nonhuman species, what percent of its amino acids are identical to the human sequence of

What type of energy does active transport use?

Which question can be tested scientifically? Does humidity affect the decay rate of leaves? How does a biologist become successful? What shape are the flowers of a cherry tree? Why do sciencet teachers like to give homework?

Which is the sign of recovery after an oil spill? A. Increases of population in sea creatures B. Detailed reports from environmental agencies C. Significant loss in revenue for fishing industries D.