Recent Estimates of the Number of Microbes on the Planet

question 61

Multiple Choice

Recent estimates of the number of microbes on the planet have expanded almost exponentially, but the number of microorganisms isolated in the lab has not increased at the same rate. How can microbiologists justify the higher estimates if they cannot isolate and grow the microbes in the lab?

• A) The huge numbers of diseases without apparent causative agents indicate there are large numbers of unidentified pathogens.
• B) Detection of novel enzymes indicates the existence of unidentified microbes.
• C) Previous estimates of the abundance of microbes cannot account for the detectable biomass in most environments.
• D) New technologies make it possible to detect the nucleic acid sequences of previously unknown organisms.
• E) Much more powerful microscopes have made it possible to observe and identify huge numbers of microbes that cannot be isolated.

---

Definitions:

Government Bonds

Debt securities issued by a government to support government spending, which investors can purchase, typically considered low-risk investments.

Accrued Interest

The accumulated interest on a note payable or receivable that has been earned but not yet received or paid out.

Semiannual Interest

Interest that is calculated and paid twice a year, often on bonds or loans.

Subsidiary Company

A company that is completely or partly owned and wholly controlled by another company, known as the parent company.