Question

multiple choice question
which is true for the possible types of comparisons using sequences of small subunit rrna molecules?

the stable regions allow comparisons between closely related microbes while the variable sequences allow comparisons between more distantly related microbes.

both the variable and stable regions allow comparisons between distantly related microbes.

the variable regions allow comparisons between closely related microbes while the stable sequences allow comparisons between more distantly related microbes.

both the variable and stable regions allow comparisons between closely related microbes.

Explanation:

Small subunit rRNA has conserved (stable) regions that change very slowly over evolutionary time, so they can be used to compare organisms that are distantly related (since these regions remain similar across long evolutionary distances). The variable regions evolve more quickly, so differences in these regions can distinguish between closely related microbes that have diverged more recently.

Answer:

The variable regions allow comparisons between closely related microbes while the stable sequences allow comparisons between more distantly related microbes.