12. Which of the cycles below involves oxygen gas? a. the carbon cycle
b. the water cycle
c. the density cycle
d. the argon cycle

Which statement describes an endocrine function rather than an exocrine function? a. salivary glands release saliva into the mouth. b. sweat glands release sweat onto the skin c. the pineal gland releases melatonin into the blood. d. esophageal glands release mucus into the esophagus.

Cassandra made a venn diagram to compare and contrast the two stages of cellular respiration. which belongs in the area marked x? energy is released. oxygen is used up. glucose is broken down. carbon dioxide is used up.

Which of the following is not a possible effectof increasimg carbon dioxide levels in the atmosphere ?