How Does Comparative Data on Genes of Extant Species Help

question 9

Multiple Choice

How does comparative data on genes of extant species help us to make estimates of what happened before the phylogenetic event horizon?

• A)Common genes must have existed for a long time.
• B)If the first life-forms consisted of RNA, then current RNA-coding genes must be the ancestral genes.
• C)Common functional genes imply the minimal characteristics of early cells.
• D)Because so many small genome bacteria are endosymbionts, the earliest cells must have been endosymbionts.

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Definitions:

Secondary Diagnosis

Diagnosis other than the primary diagnosis for other conditions that are also affecting the patient at the time of the visit.

Primary Diagnosis

The main medical diagnosis determined after evaluation, representing the most serious or significant condition that prompted the medical encounter.

ICD-10

The International Classification of Diseases, 10th Revision, a medical classification list by the World Health Organization, which codes for diseases, signs and symptoms, abnormal findings, and external causes of injury or diseases.

ICD-9

The International Classification of Diseases, Ninth Revision (ICD-9) is a set of codes used to classify diseases and a wide variety of symptoms, injuries, and causes of death, facilitating uniform data collection and reporting.