Question 1 of 5 Following a volcanic eruption, which event is usually the last one to be
observed?
A. Grasses begin to grow in soil with organic matter
B. Lichens begin to cover bare rock.
C. Mosses begin to grow in thin, rocky soil.
D. Trees begin to grow in thick, rich soil.

What sentence best supports the statement that hormones are involved in the regulation of homeostasis? a. the hormone erythropoeitin increases the production of red blood cells when oxygen levels are low. b. the hormone oxytocin promotes labor contractions of the uterus during childbirth. c. the hormone melatonin induces sleep and its production is slowed by exposure to light. d. the hormone cortisol suppresses the immune system and is produced when the body is under stress.

Which statement describes characteristics of planarians? a they live in oceans, are parasites, and reproduce only sexually. b they live in fresh water, are parasites, and reproduce only asexually. c they live in oceans, are free living, and reproduce sexually and asexually. d they live in fresh water, are free living, and reproduce sexually and asexually.

What is the difference between a scientific hypotheses and a scientific theory?