Why Did the Miller‒Urey Hot Chemistry Experiment Exclude Oxygen in Its

question 146

Multiple Choice

Why did the Miller‒Urey hot chemistry experiment exclude oxygen in its investigation of the chemical origin of life on Earth?

• A) Oxygen is not necessary for life.
• B) The scientists assumed the reactions would produce oxygen from water vapor.
• C) The scientists assumed that photosynthetic organisms would develop in the apparatus.
• D) There is no evidence that oxygen existed in Earth's earliest environments.
• E) The scientists wanted to avoid contamination of the apparatus by oxygen-consuming bacteria.

Recognize patterns of forgetting and memory retention over time.

Comprehend the effects of mood on memory recall.

Understand the nature of flashbulb memories and their reliability.

Recognize common reasons for everyday memory lapses.

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Definitions:

Contribution Margin Percentage

A measure showing what percentage of sales revenue is available to cover fixed costs and contribute to net income, calculated as (Sales - Variable Costs) / Sales.

After-Tax Profit

The profit a company has left after paying all its taxes.

Tax Rate

The proportion of income that the government taxes an individual or business.

Profit and Loss Statement

A financial statement that summarizes revenues, costs, and expenses incurred during a specific period, usually a fiscal quarter or year.