Which structure of the excretory system in humans is responsible for converting ammonia into urea?

Why are scientists concerned about the depletion of the ozone levels in the stratosphere?

What evidence did mendel find that supported his law of independent assortment? a. some traits are controlled by several different genes. b. a trait can be passed on from a parent to an offspring. c. most traits have a dominant form and a recessive form. d. different traits are passed on independently of each other.

Hemoglobin is a proton that carries oxygen around your body what is hemoglobin made from