Answer:
Mammals first appeared
Explanation:
The dinosaurs became extinct one million years after the Cenozoic era started. The mammals first appeared as the modern culture first appeared in that era.
The periodic table only accounts for elements. It does not account for compounds, such as water.
Three of the four nitrogenous bases that make up RNA — adenine (A), cytosine (C), and guanine (G) — are also found in DNA. In RNA, however, a base called uracil (U) replaces thymine (T) as the complementary nucleotide to adenine (Figure 3). ... (Remember, DNA is almost always in a double-stranded helical form.)
Explanation:
They are hydrophobic. About 5 amino acids have polar side chains, R-groups which do not ionize or become positively or negatively charged. These R-groups are neither strongly hydrophilic nor hydrophobic. Atoms in long molecules, such as polypeptides, are not rigidly fixed in space or position
