Final answer:
Onion root tip cells and white fish blastula cells are both eukaryotic cells that undergo mitosis. Hence the correct answer is option 4
Step-by-step explanation:
The similarities between onion root tip cells and white fish blastula cells are that both are eukaryotic cells and both undergo mitosis to divide and grow. Onion root tip cells are plant cells, while white fish blastula cells are animal cells. So, the correct option would be 4) Both are eukaryotic cells.