| # | Clue | Answer As Given | Value | Round | Category | Air Date | Show |
|---|---|---|---|---|---|---|---|
| By definition an aerobe is an organism that lives only in the presence of this element | oxygen | $400 | DJ | BIOLOGY | 2020-12-18 | #8305 | |
| By definition bacteria called anaerobes don't need this to live | oxygen | $200 | J | BIOLOGY | 2017-07-21 | #7580 | |
| This pure gas is a by-product of photosynthesis | oxygen | $200 | J | BIOLOGY | 1991-10-25 | #1645 | |
| An aerobe can live only in an environment where this element is present in free form | oxygen | $400 | DJ | BIOLOGY | 1991-01-31 | #1484 |