In the winter, cold, dry air masses tend to dominate the central and eastern United States as cold winds blow from the northwestern Canadian prairies. In summer, the warm southern winds blow moist, hot air into the eastern and central US, leading to days of high humidity and sultry conditions. In spring and fall, moving low and high pressure areas pull alternating warm and cold air masses across a given area, leading to a lot of variability in day-to-day weather.
Messenger RNA (mRNA) molecules carry the coding sequences for protein synthesis and are called transcripts; ribosomal RNA (rRNA) molecules form the core of a cell's ribosomes (the structures in which protein synthesis takes place); and transfer RNA (tRNA) molecules carry amino acids to the ribosomes during protein.
Answer:
The correct answer would be A. It has DNA that is not contained within a nucleus.
The main difference between prokaryotic and eukaryotic cell is the absence of a well-defined nucleus and other membrane-bound organelles like the Golgi body, mitochondria et cetera in a prokaryotic cell.
The DNA in the prokaryotic cell floats freely in the cytoplasm in the region called nucleoid which means nucleus-like.
Thus, an observation like the absence of a nucleus can provide the evidence that a cell is most likely a prokaryote.
