Solve these clues to fill the grid.
- Tiny single-celled living things, some of which cause illness
- 4 Across
- Descent of the uterus into the pelvic cavity that occurs late in pregnancy
- 6 Across
- The analysis of a vector field
- 8 Across
- The part of the earth's surface consisting of humus and disintegrated rock
- 10 Across
- An interval during which a recurring sequence of events occurs
- 1 Down
- A common nonmetallic element that is normally a colorless odorless tasteless inert diatomic gas
- 2 Down
- The natural world around us
- 3 Down
- Living things like dogs and birds
- 5 Down
- The usually underground organ that lacks buds or leaves or nodes (plural)
- 7 Down
- Living things like trees and flowers that grow in soil
- 9 Down