WHAT ARE THREE PARTS OF STRANDS

Three parts of a strand, specifically a DNA strand, are:

1. Sugar-phosphate Backbone: This is the main structural component of the DNA strand. It is made up of repeating units of sugar molecules (deoxyribose) and phosphate groups. These sugar-phosphate units are connected by covalent bonds known as phosphodiester bonds.
2. Nitrogenous Bases: These are the chemical units that make up the genetic code in DNA. There are four types of nitrogenous bases: adenine (A), thymine (T), cytosine (C), and guanine (G). These bases are responsible for pairing between two DNA strands, with adenine always pairing with thymine (A-T) and cytosine always pairing with guanine (C-G).
3. Hydrogen Bonds: These are weak chemical bonds that hold the two DNA strands together. Specifically, hydrogen bonds occur between the nitrogenous bases of the complementary DNA strands. Each base pair (A-T or C-G) forms a specific number of hydrogen bonds - A-T pairs have two hydrogen bonds, while C-G pairs have three hydrogen bonds.

To obtain this information, you can refer to a basic biology textbook, search online resources such as educational websites or scientific databases, or consult scientific papers or articles related to DNA structure.