The nine different classes of vertebrates include
a. four fish classes and amphibians, reptiles, birds, whales and mammals.
b. four fish classes and amphibians, reptiles, birds, mammals and primates.
c. five fish classes and amphibians, reptiles, birds, and mammals.
d. five fish classes and amphibians, reptiles, monkeys, and mammals.

Ectocarpene is a volatile, sperm cell-attracting material released by the eggs of the seaweed ectocarpus siliculosus. its constitution is all the double bonds are cis, and the absolute configuration of the chirality center is s. draw a stereochemically accurate representation of ectocarpene.

This class has taught you that the use of science and medicine in practical ways has become an international endeavor. one of the greatest examples of an international science accomplishment is which allows the profiling of human dna, useful not only to science but also medicine. a) forensic science b) the fbi c) the human genome project d) bioterrorism

Veins have a much lower blood pressure than arteries. which of these prevents backflow of blood in veins? a. pressure applied by the heart b. one–way valves in veins c. thin muscular walls of veins