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%

Biology & Microbiology

You might also like to view...

The chemical group box 1 in the accompanying figure is a:

a. pyrimidine. b. purine. c. phosphate. d. amino acid. e. covalent bond

Biology & Microbiology

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.

Biology & Microbiology

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.

Biology & Microbiology

Animal cells have all of the following EXCEPT:

A) a nuclear envelope B) mitochondria C) golgi apparatus D) chloroplasts

Biology & Microbiology