Which of these body systems has cells that attach to each other to form a leak-proof barrier? Select one:

Urinary system.

Reproductive system.

Respiratory system.

Endocrine system.

If the rna molecule in a human has the nucleotide sequence of guu, this would the amino acid valine would be needed to make the protein. how would this cha process was occurring in a mushroom?

When sodium chloride dissolves in water the sodium cholride dissociates into?

Which two animals are most closely related? explain.