If the half-life of uranium-235 is 700 million years and you have 16 atoms of it, how many half-lives
(700-million-year units of time) will pass before only
1 atom of uranium-235 is left?
A. 7
B. 6
C. 5
D. 4
SUBMIT

Which is an important function of normal flora? a. aid with bone marrow production. b. crowd out pathogenic bacteria. c. destroy digestive track pathogens. d. manufacture iron in the bloodstream.

What does polymerase chain reaction (pcr) do? o a. separates dna fragments by size o b. cuts a dna sample into fragments o c. provides an overall picture of a person's chromosomes o d. makes more copies of a sample of dna

The polio virus can cause skeletal muscle paralysis by destroying neuron cell bodies. what area of the spinal cord is destroyed