*Question*
Q: What is the smallest class of elements? Choices: - halogens - noble gases - synthetics - metalloids A:
**Answer**
metalloids

*Question*
Q: What is an isotope that is radioactive called? Choices: - isotopes - matured isotope - radionuclides - radioisotopes A:
**Answer**
radioisotopes

*Question*
Q: What takes over the synthesis and secretion of progesterone throughout pregnancy as the corpus luteum degenerates? Choices: - vagina - uterus - ovaries - placenta A:
**Answer**
placenta

*Question*
Q: What are the building blocks of life? Choices: - muscles - seeds - bricks - cells A:
**Answer**
cells