26. Which of the following structures is the smallest?

A. Viriod
B. Hydrogen atom
C. Bacterium
D. Mitochondrion

27. Which of the following is/are included in Kingdom Prokaryotae?

A. Bacteria
B. Protozoa
C. Fungi
D. All of these

28. Which of the following may account for the small size of the cells?

A. The rate of diffusion
B. The surface area/volume ratio
C. The number of mRNAs that can be produced by the nucleus
D. All of the above

29. Genetic and biochemical similarities between contemporary cyanobacteria and eukaryotic chloroplasts are accepted to mean that

A. eukaryotes evolved from bacteria
B. eukaryotes evolved from archaea
C. oxygenic photosynthesis first evolved in eukaryotes
D. cyanobacteria arose from chloroplasts which escaped from plant cells

30. Which of the following best represents the hierarchy of levels of biological classification?

A. Phylum, kingdom, class, order, genus, species, family
B. Kingdom, phylum, class, order, family, genus, species
C. Kingdom, phylum, family, class, order, genus, species
D. Class, order, kingdom, phylum, family, genus, species