What are the only totipotent cells in humans?

Sperm are the only human cells to have a flagellum. This is their "tail". They are also one of only two cells to have haploid number of chromosomes. The ova in females is also haploid.

protein

not sure

Ova (eggs) in females and sperm in males are haploid cells.

there are binucleated cells in the liver and in the transitional epithelium of the urinary bladder