*Question*
Q: What is the process in which gases are exchanged between the body and the outside air?    Choices:  - ingestion  - metabolism  - precipitation  - respiration  A:
**Answer**
respiration

*Question*
Q: What shape is the gametophyte in ferns?    Choices:  - circular  - rectangular  - diamond  - heart-shaped  A:
**Answer**
heart-shaped

*Question*
Q: What involves the emission of a particle and/or energy as one atom changes into another?    Choices:  - spontaneous mutation  - atomic transformation  - enthalpy  - radioactive decay  A:
**Answer**
radioactive decay

*Question*
Q: Changes in the number of what can lead to disorders like down syndrome?    Choices:  - prokaryotes  - dna  - genes  - chromosomes  A:
**Answer**

chromosomes