Which of the following groups had made their appearance during the Ordovician period?
A. jawed fish and amphibians
B. jawless and jawed fish
C. amphibians and reptiles
D. reptiles and mammals
E. All of these groups had appeared by the Ordovician period.
Answer: B
Biology & Microbiology
You might also like to view...
Compact bone is indicated by
a. A. b. B. c. C. d. D. e. E.
Biology & Microbiology
The term hormone comes from the Greek word meaning ____
a. to target b. to synthesize c. to excite d. to inhibit e. to multiply
Biology & Microbiology
Semen is mixture of what?
What will be an ideal response?
Biology & Microbiology
Delayed hypersensitivity is ____ mediated.
A. humoral B. antibody C. cell
Biology & Microbiology