This illustration shows that after two half-lives,
__________ percent of the parent radioisotope has
decayed.
a. 100
b. 75
c. 50
d. 25
e. 0
Answer: b
You might also like to view...
Cnidarians, such as __________________, have muscle fibers
A. clams B. earthworms C. jelly fish D. sea corals
One of the basic principles of evolution is the concept of ____
a. genetic drift b. divergent physiology c. economic diversity d. a shared ancestor e. creationism
An Rh-negative mother will need a special treatment if she gives birth to an Rh-positive baby. The treatment involves the destruction of any stray blood cells from the baby that pass into the mother's bloodstream. Why is this necessary?
A) The mother's immune system will attack the Rh-positive cells and produce antibodies that will attack a fetus in a subsequent pregnancy. B) The mother's immune system will attack her own blood cells and the cells in the fetus of a subsequent pregnancy. C) Without this treatment, the mother's immune system will attack only her own blood cells. D) Without this treatment, antibodies will be formed in breast milk, which could harm the baby.
Which of the following would be likely to require facilitated diffusion to move across the plasma membrane?
a. water (H2O) b. sodium ions (Na+), hydrogen ions (H+), sugars, and amino acids c. oxygen (O2) d. carbon dioxide (CO2)