gas exchange occurs in the human lungs.
DNA is present within the nucleus of the cells and it is responsible for the production of various proteins and enzymes to keep the cellular activity going on. However, it cannot directly do so and seeks help of the messenger RNA molecules. DNA transcription is a process that involves transfer of the DNA code from the DNA to the mRNA molecule for the production of proteins.
The Grand Canyon is made of sedimentary rock that contains fossils up to 1 billion years old. and the several upper layers of rock contain terrestrial, or land-based, fossils, such as dragonfly wing impressions and the footprints of scorpions, centipedes, and reptiles
Your answer is A) Recombinant DNA. I just took this quiz. Thanks