How Do Comparative Data on Genes of Extant Species Help

question 6

Multiple Choice

How do 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, possibly since the first life-forms.
• B) Common functional genes imply the minimal characteristics of early cells.
• C) If the first life-forms consisted of RNA, then current RNA-coding genes must be the ancestral genes.
• D) The first life-forms must have been endosymbionts because most small-genome extant bacteria are endosymbionts.

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Definitions:

Equivalent Units

A concept in cost accounting used to allocate costs to produced units based on the amount of work completed.

Conversion Cost

The sum of direct labor and manufacturing overhead costs, representing the costs to convert raw materials into finished goods.

Equivalent Units

A concept used in cost accounting to convert units of production into an amount of completed units to measure progress.

Conversion Costs

Costs specifically associated with converting raw materials into finished goods, which include labor and overhead.