<span>useful substances must be selectively reabsorbed
Filtration of blood by kidney only selected based on the molecule size. That means all small molecule will enter the kidney, doesn't matter whether it is toxic or useful.
But kidney has another mechanism such as reabsorption. In </span>reabsorption, some specific useful molecule(like glucose) will be absorbed back.
Cephalization in animals occurs with other features
Bilatery symmetry
Not all organism in phylum chordata have vertebrate
False
They are called as Noble gases. Hope it helped you. Please mark as the brainliest answer if it helped.