When a certain plant is without water for an extended period of time, guard cells close openings in the leaves of the plant, conserving water. What does this illustrate?

Select the correct answer from each drop-down menu. What is thermal pollution? Thermal pollution is the artificial warming of {drinkin, tap or natural} water by hot water discharged from factories and power plants.

Which type of lipid acts as a chemical messenger? A. Adipose tissue B. Cholesteral C. Testosterone D. beeswax

How might Schwann's observations about embryos have affected the theory of spontaneous generation?

Which substances are produced as waste products by plants in different processes? A) Oxygen and urine B) Carbon dioxide and oxygen C) Carbon dioxide and Uric acid D) Carbon dioxide and urine

Why can the reduction in melting temperature for hybrid DNA between two mammalian species be used to predict how long it has been since those species diverged from a common ancestor? A., Mutations in DNA accumulate at a fairly constant rate. B.

Which of these is a scientific hypothesis? A) Researchers have observed that high blood pressure is often associated with excessive urination.

What is the difference between Gram-positive and Gram-negative bacteria? Why is this distinction important to doctors?

Which of the following is not a macronutrient? A) Carbohydrates B) Protein C) Vitamin C D) Fat

Agglutinins are surface antigens on RBCs. contain abundant stained "granules." prevent blood clotting. are antibodies that will attack surface antigens on RBCs of a different blood type.

Which of the following best explains why humans need constant supplies of fresh water? a. Humans need a constant supply of water to provide them with essential vitamins. b. Humans need a constant supply of water to maintain proper hygiene. c.