The DNA Double Helix Is Similar to a Twisted Ladder

question 60

Multiple Choice

The DNA double helix is similar to a twisted ladder.What makes up the sides holding the rungs together?

• A)phosphate groups only
• B)alternating units of phosphate groups and sugars
• C)sugars only
• D)purines and pyrimidines

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Definitions:

Pure Water

Water that has been purified to remove impurities, consisting only of H2O molecules.

Acidity

A measure of the concentration of hydrogen ions in a solution, indicating how acidic or alkaline the solution is.

Hydrogen Ions

Positively charged ions (H+) that are formed when hydrogen atoms lose their electrons; a high concentration of hydrogen ions indicates acidity.

Protons

Positively charged subatomic particles found in the nucleus of an atom, determining the element's atomic number.