Across
- 3. mammals with pouches
- 5. stinging animal
- 11. fertilization inside a body
- 12. wormlike larva
- 13. mammals
- 14. reptiles and birds
- 15. warm bloodied animals
Down
- 1. simplest group of invertebrates
- 2. mosquito larva
- 4. one parent reproduction
- 6. union of sperm and egg cell
- 7. white part of the egg
- 8. platypus and anteater
- 9. cufflike band
- 10. series of changes