Answer: DNA molecule
Explanation:Chromosomes are made of long chains of molecules called DNA (Deoxyribonucleic acid). DNA is a complex molecule that contains the genetic instructions for the development, functioning, and reproduction of all living organisms.
DNA is composed of smaller units called nucleotides, which are linked together to form the long chains. Each nucleotide consists of a sugar molecule, a phosphate group, and one of four nitrogenous bases: adenine (A), thymine (T), cytosine (C), and guanine (G).
The sequence of these nitrogenous bases in DNA determines the genetic code. It is this code that carries the instructions for the production of proteins, which are essential for the structure and function of cells.
The DNA molecule is structured as a double helix, where two strands of DNA wind around each other in a spiral shape. The nitrogenous bases from one strand form hydrogen bonds with the complementary bases on the opposite strand, creating a stable structure.
Chromosomes are formed when DNA molecules are tightly coiled and condensed. In humans, each cell typically contains 46 chromosomes, arranged in 23 pairs. These chromosomes carry the genetic information that is passed from parents to offspring during reproduction.
In summary, chromosomes are made of long chains of DNA molecules. DNA consists of nucleotides, which are composed of a sugar, a phosphate group, and one of four nitrogenous bases. The sequence of these bases carries the genetic instructions for the development and functioning of living organisms.