*Question*
Q: What part of the muscle fibers cause shortening and contraction? Choices: - fasciae - pores - collagen - myofibrils A:
**Answer**
myofibrils

*Question*
Q: What term is used to describe large numbers of species that go extinct in a short amount of time? Choices: - formation extinction - organic extinction - species extinction - mass extinction A:
**Answer**
mass extinction

*Question*
Q: Organs that produce eggs and secrete estrogen are part of what system? Choices: - circulatory system - digestive system - male reproductive system - female reproductive system A:
**Answer**
female reproductive system

*Question*
Q: Distance traveled divided by time yields what measurement, which is another word used to describe the speed of a chemical reaction? Choices: - flow - displacement - acceleration - rate A:
**Answer**
rate