Which of the Following Statements About DNA Is True

question 39

Multiple Choice

Which of the following statements about DNA is true?

• A) The DNA molecule is circular, with the nucleotide bases located in the center of the circle.
• B) The DNA molecule contains only four different types of bases, regardless of what species is involved.
• C) The DNA molecule is identical for every known species, and species differences are coded on molecules that lay alongside the DNA.
• D) The pairing of adenine, thymine, cytosine, and guanine follows a random sequence, with all four base pairs combining with each other an equal percentage of times.

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Definitions:

Endorphins

Naturally occurring peptides produced in the brain that act as neurotransmitters to reduce the perception of pain and promote feelings of pleasure.

Morphine

An opiate analgesic derived from the opium poppy used for pain relief.

Sympathetic Systems

A part of the autonomic nervous system responsible for the body's 'fight or flight' response to stressful situations.

Parasympathetic Systems

A branch of the autonomic nervous system responsible for conserving energy and reducing the heart rate.