The four bases in DNA are: adenine, thymine, cytosine, guanine.
In RNA, thymine gets replaced by uracil.
Purine is only a name for the two bases guanine and adenine.
What cells are you talking about?
<span>Simple.
All of the millions of different life forms (the diversity of life) have come about by natural selection, whereby random mutations in the genes have either succeeded or failed.
But all life can be traced back to a common single-celled origin. Thus we have the unity of life where we (possibly) share more than 50 % of our DNA with a crocodile.eg:analogous organs, homologous organs.</span>
1. Animals
2. Plants
3. Virus
4. Prokaryote
Carrier proteins are the proteins in active transport