If a radioactive isotope has a half-life of 20 million year, and there is 25% remaining in the igneous rock. How old is the rock?

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.

About how much of the cell mass is watet

3test questions with answers on incomplete dominance