Across
- 6. The study of similarities and differences among structures of different species
- 7. The science of the development of embryos from fertilization to birth
- 8. The study of gene structure and function
- 9. body part of organisms that are similar in structure and position but different in function
Down
- 1. body parts that perform a similar function but differ in structure
- 2. Body parts that have lost their original function through evolution
- 3. develops into gills in some organisms
- 4. a protein required for cellular respiration
- 5. The source of variations upon which natural selection acts