The oxidizing atmosphere probably developed about _____ billion years ago.
A. 1.5
B. 2.5
C. 3.5
D. 4.5
Ans: B. 2.5
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Most of the drugs used to treat protozoan infection have insignificant side effects; because protozoa are prokaryotes, the potential for drug action on host cells and tissues is less than it is when targeting bacteria.
Answer the following statement true (T) or false (F)
2. An epithelial tissue formed by more than one layer of cells and with column-like cells at the surface is called
(a) simple squamous. (b) stratified squamous. (c) simple columnar. (d) stratified columnar.
Anchovies are an efficient fish to catch because they:
a. are grazers. b. are filter feeders. c. travel in large dense schools. d. are small fish. e. swim quickly.
The key innovation that helped sporophyte
dominant plants survive in dry environments is a. spores. b. the cuticle. c. xylem. d. phloem. e. lignin.