SUMMARY: This is an article comparing the structural and genomic differences between ciliates and flagellates. Dinoflagellates seem to be the ancestors of ciliates based on similarities in various cell structures and rRNA sequencing. Structures compared in this article include: mitochondria, mechanisms of cilia and flagella, nucleus, and how flagellate and ciliates consume food. In order to look at the genomic sequences, scientists compared rRNA and mRNA codons. Differences in rRNA sequences and use of different codons in mRNA by the protozoa show how they diverged in the past into different branches on the phylogenic tree.
LESSON COMMENTS: Students can see the difference between classifying organisms based on phenotype versus sequencing genomes. Topics covered here include: parts of the cell and cell organelles, using RNA structure to identify genes, sequencing technology, nucleotide and complement bases, protozoa physiology, taxonomy and classification, and evolution of protozoa.
Lee, R. E., & Kugrens, P. (1992). Relationship between the flagellates and the ciliates. Microbiological reviews, 56(4), 529-42.