5. the change in isotopes over time due to the emission of radioactive particles is known as
a. absolute-age dating.
b. half-life.
c. radiometric dating.
d. radioactive decay.

Which of the following is a main difference in cell structure between an onion cell and a human cheek cell? a. an onion cell contains one nucleus, whereas a human cheek cell contains two nuclei. b. an onion cell has a cell wall. c. a human cheek cell contains chloroplasts. d. there is no difference between an onion cell and a human cheek cell. you for your.

Which is an example of a decomposer? a. bear b.algae c.grass d.bacteria d bacteria

In which part of the body is a ball-and-socket joint found?