Scientists have learned that when a pregnant woman smokes, one of the chemicals absorbed, nicotine, can narrow the diameter of her blood vessels that lead to the placenta. Explain why narrowing the diameter of these blood vessels can result in low birth weight babies.

Sand spinifex grass is adapted to growing on sand dunes. it is a rapidly spreading plant and the creeping runners produce new root systems. which of these best explains the benefits of these features? a. it limits water loss through the leaves. b. it provides support by anchoring the plant. c. it protects the plant from predators. d. it allows the plant to tolerate salt. reset submit

This comparative chart is an example of one that might be used by scientists and law enforcement personnel for identification purposes. the chart represents a technological advance called

Describe the relationship between isotonic solutions, equilibrium, and water movement into and out of a cell.