Select the most correct statement.
a. the immune system is closely associated with the lymphatic system.
b. the endocrine system is not a true structural organ system.
c. organ systems operate independently of each other to maintain life.
d. organ systems can be composed of cells or tissues, but not both.

Select the correct answer. which mutation is harmful to the organism? a. a mutation allowing moths to camouflage better on blackened tree bark b. a mutation making staphylococcus aureus resistant to the antibiotic methicillin c. a mutation inhibiting human immunodeficiency virus from attaching to and entering the cell d. a mutation causing uncontrolled cell division e. a mutation giving plant leaves a bitter taste to discourage herbivores from eating them

The two tubes contain bromothymol blue. after 24 hours, what will the color of the water be in tube b? a. green (it won't change) b. yellow c. blue d. colorless (clear)

Describe the two types of vascular tissue