The genes encoding smallsubunit ribosomal RNAs are useful fo

The genes encoding small-subunit ribosomal RNAs are useful for reconstructing the phylogeny of all organisms. Why might this be true?

All of the answers

the gene\'s function has stayed unchanged in all organisms

all organisms have ribosomes with similar composition and structure

all organisms have the gene

the gene is subject to strong stabilizing selection

Solution

This is true because all organisms have the gene which possess ribosome performing same function to encode protein of different amino acid composition.