Final answer:
Ribosomal RNA (rRNA) constitutes the majority of total RNA extracted from a cell, outweighing other species like mRNA and tRNA due to its structural and enzymatic roles in ribosomes, which are essential for protein synthesis.
Step-by-step explanation:
Total RNA extracted from a eukaryotic cell is predominately made up of rRNA. While messenger RNA (mRNA) is often the focus of genetic studies due to its role in coding for proteins, it only represents a small percentage of the cell's total RNA content. Ribosomal RNA is a structural as well as an enzymatic component of ribosomes, which are the cellular machinery for protein synthesis. In terms of quantity, rRNAs are the most abundant RNA molecules found within the cell. The high abundance of rRNA is because they are not only key structural components but also play a critical role in the translation process, acting as an enzymatic catalyst within ribosomes.
Other types of RNA, such as transfer RNA (tRNA) and small RNA molecules like microRNAs (miRNAs) and small interfering RNAs (siRNAs), are also present within the cell but in smaller quantities compared to rRNA. The process of RNA extraction typically involves separating RNA from cellular debris and preserving it from degradation by RNases, which are enzymes that break down RNA.