For a span of some 300 million years, the Paleozoic era, in which vascular plants, fishes, and other diverse life appeared, lasted approximately ___ of the geologic timescale.
A. 7%
B. 15%
C. None of the answer choices is correct.
D. 50%
E. 85%
A. 7%
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The change in Gibbs free energy for a particular reaction is MOST useful in determining
A) the amount of energy catalysts required for biosynthesis or catabolism. B) the potential metabolic reaction rate. C) whether there will be a requirement or production of energy. D) energy stored in each compound.
The chemical group box 1 in the accompanying figure is a:
a. pyrimidine. b. purine. c. phosphate. d. amino acid. e. covalent bond
Saccharomyces is commonly known as
A. an antibiotic. B. the "death angel." C. mildew. D. yeast for making bread, wine, and beer. E. the common bread mold.
Animal cells have all of the following EXCEPT:
A) a nuclear envelope B) mitochondria C) golgi apparatus D) chloroplasts