Approximately How Many Elements Occur Naturally on Earth

question 58

Multiple Choice

Approximately how many elements occur naturally on Earth?

• A)20
• B)60
• C)90
• D)115

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Definitions:

Chromosomes

Structures within cells that contain DNA and carry genetic information necessary for reproduction, growth, and maintenance.

Nucleotide Bases

Organic molecules that serve as the fundamental building blocks of nucleic acids, like DNA and RNA, consisting of adenine, thymine (or uracil in RNA), cytosine, and guanine.

Histamine

A compound that is involved in local immune responses, as well as regulating physiological functions in the gut and acting as a neurotransmitter for the brain, spinal cord, and uterus.

Membrane Channels

Proteins in cell membranes that regulate the passage of ions and molecules in and out of the cell, playing crucial roles in cell signaling and homeostasis.