The bark of a tree is impervious to gases and water because bark cells are dead cells of the epidermis and compactly arranged without intercellular spaces. They contain a chemical called suberin in their walls that make them impervious to gases and water and it doesn't allow gases or water into the tree as bark cells are in the bark outer most layer of the tree.
Answer:
Phoebus Levene
Explanation:
Since he performed hydrolysis experiments on nucleic acid. He also discovered that DNA is composed as a series of monomers called nucleotide.
Answer:
Explanation:
In the Hershey and Chase experiment, they aimed to show where the phage DNA went when it exited the protein coat and entered the bacteria. In this scenario, the two student's approach won't work because amino acids (and therefore all proteins) also have nitrogen atoms which ultimately means that the radioactivity would not distinguish between DNA and proteins and the experiment will not provide the correct results.
Semen is the correct answer
