Because nutrients are the building blocks of cellular parts, a lack of nutrients can reduce the ability of cells to build new molecules that protect them from environmental stress. Dorival Martins and Ann English (2014) investigated this phenomenon with Saccharomyces cerevisiae yeast exposed to hydrogen peroxide. The researchers grew three cultures of yeast on a nutrient-rich solution and three cultures of yeast on a nutrient-poor solution. They then exposed each yeast culture to 0.2mM hydrogen peroxide and measured catalase activity (U/mg). Required:
Identify the independent variable.

Which greenhouse gas is emitted when burn fossil fuels for energy? a. nitrogen b. oxygen c. carbon dioxide d. helium

What molecule contains an organisms genetic material, passed down from parents to their offspring

Which of these is true of the cytoplasm of an unfertilized egg? a. it is an unevenly distributed mixture of mrna, proteins, organelles, and other substances. b. it does not contain substances that are important in directing development. c. these substances are supplied by the sperm. d. it does not contain substances that are important in directing development. e. development is directed solely by the surrounding cells. f. it is a homogeneous mixture of mrna, proteins, organelles, and other substances. g. it does not contain substances that are important in directing development. h. these substances are produced by the dna of the fertilized zygote.