The Level of Oxygen in the Form of O₂ in the Earth's

question 26

Multiple Choice

The level of oxygen in the form of O₂ in the Earth's atmosphere ________________.

• A)has not changed substantially in the past 450 million years
• B)is drastically decreasing due to pollution
• C)is no different than it was 4.6 billion years ago
• D)is drastically increasing due to growth of new bacterial strains
• E)cannot change because Earth is a closed system

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Definitions:

Genetics

The study of heredity and the variation of inherited characteristics.

Transmitting Characteristics

The process of passing genetic traits or cultural attributes from one generation to the next.

Genetically

Pertaining to genes and the transfer of characteristics from parents to offspring through DNA in the process of inheritance.

Fertilized Egg

The cell that results from the union of a sperm and an ovum, marking the beginning of embryonic development.