Living things contain units of structure and function that arise from preexisting units. This statement best describes the A) cell theory
B) lock-and-key model of enzyme activity C) concept of natural selection
D) heterotroph hypothesis

Cells tend to have a relatively small and uniform size. why aren’t cells larger?

2. what process do mrna and trna work together to complete? (3 points)

How is ribosomal rna useful as a molecular clock? a. a large portion of the dna ring is not vital to structure or function, allowing it to accumulate neutral mutations. b. its rate of mutation increases over time as organisms continue to evolve and differentiate from each other. c. a slow mutation rate makes it useful for determining evolutionary relationships between ancient species. d. it is only found in select organisms, making it easier to compare relationships between species that have it.