Solve these clues to fill the grid.
- A belt-shaped region in the heavens on either side to the ecliptic
- 1 Across
- The diploid cell resulting from the union of a haploid spermatozoon and ovum
- 2 Across
- The branch of biology that studies animals
- 5 Across
- Marrow squash plant whose fruit are eaten when small
- 6 Across
- A ___ of letters and digits added to a postal address to aid in the sorting of mail
- 7 Across
- Animal constituent of plankton
- 9 Across
- A locally circumscribed place characterized by some distinctive features
- 10 Across
- The act of rising upward into the air
- 11 Across
- A fastener for locking together two toothed edges by means of a sliding tab
- 13 Across
- The point above the observer that is directly opposite the nadir on the imaginary sphere against
- 1 Down
- A bluish-white lustrous metallic element
- 2 Down
- An angular shape characterized by sharp turns in alternating directions
- 3 Down
- To regulate housing in
- 4 Down
- A lustrous grey strong metallic element resembling titanium
- 5 Down
- Of or relating to or constituting ___
- 8 Down
- The sight setting that will cause a projectile to hit the center of the target with no wind blowing
- 12 Down