Where Do Trees Come From? From Heaven or Earth?

Chemistry, Plants
Where do trees come from, from heaven or earth? This is not the philosophical discussion it might at first seem to be. Even in the Bible, heaven sometimes refers, not to the residence of the Almighty, but to that region of the atmosphere in which birds fly.¹ Do trees come from the soil or from the air? Most would probably say, “from the soil.” But is that the case? What are trees primarily made of? Largely they consist of cellulose and sugar, although there are smaller quantities of other substances. Cellulose is simply sugar molecules linked together with the loss of a single molecule of water between each sugar molecule. The molecules that build up a tree are carbon-based. There are traces of other substances, but only traces. For instance,…
Read More

Are They Alive? DNA, Viruses, Gametes

Biology
[caption id="attachment_7797" align="alignright" width="380"] Varicella (chicken pox) virus. - Image CDC by Palmer and Bartin.[/caption] Some things may be associated with life, but the question remains: are they alive? Without turning this into a deeply scientific or philosophical discussion, an interesting question to ask in the proper context might be: Are they alive? We will consider a few examples of when this question might be appropriate. Is DNA alive? Do viruses live? Are an egg and a sperm alive before conception? Arguing the Case: One The DNA (deoxyribonucleic acid) molecule is a complex chemical species that varies considerably, but shares a basic commonality in whichever life form it constitutes a part. Thus the DNA of a frog is similar to the DNA of an ox, is similar to the DNA…
Read More