Concerning Dark Energy, We Do Know

question 144

Multiple Choice

Concerning dark energy, we do know

• A) that it is created when matter annihilates anti- matter.
• B) that it was revealed with Type II supernovae distances in the late 1990s.
• C) its density remains constant over time, so it is not important in the early universe.
• D) that it makes up 90% of all the matter and energy in the whole universe.
• E) combined with dark matter, it will ultimately produce a closed universe.

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Definitions:

Exocytosis

A process by which a cell transports secretory products through the cell membrane to the outside of the cell in vesicles.

Transporters

Proteins that move molecules across cell membranes, either into or out of the cell.

Cell Membrane

The semipermeable membrane surrounding the cytoplasm of a cell, which regulates the passage of substances in and out of the cell.

Protein Molecules

Large, complex molecules that play many critical roles in the body, including catalyzing metabolic reactions, DNA replication, and transporting molecules.