Answer:
Base pairs occur when nitrogenous bases make hydrogen bonds with each other. Each base has a specific partner: guanine with cytosine, adenine with thymine (in DNA) or adenine with uracil (in RNA). The hydrogen bonds are weak, allowing DNA to 'unzip'.
I think the correct answer from the choices listed above is option A. The main function of structural adaptations is that they help the organism survive in its environment. These adaptations are physical features of an organism like the bill on a bird or the fur on a bear.
Question 1
A. They are both unicellular
Question 2
B. there are three types of cells, prokaryotic, eukaryotic plant, and eukaryotic animal.
