Which of the following units are repeatedly joined together to form a strand of DNA?
A
amino acids
B
fatty acids
C
nucleotides
D
polysaccharides
C
nucleotides
The units that are repeatedly joined together to form a strand of DNA are nucleotides.
To determine which of the units are repeatedly joined together to form a strand of DNA, we can look at the options provided and understand the structure of DNA.
DNA, or deoxyribonucleic acid, is a long molecule that contains the genetic instructions used in the development and functioning of all known living organisms. It consists of two long strands that are twisted into a double helix shape.
The building blocks of DNA are nucleotides. A nucleotide consists of three components: a sugar molecule (deoxyribose), a phosphate group, and a nitrogenous base. The four nitrogenous bases found in DNA are adenine (A), cytosine (C), guanine (G), and thymine (T). These bases pair up with one another: A with T, and C with G.
Based on this information, we can conclude that the correct answer is option C: nucleotides. Nucleotides are repeatedly joined together to form a strand of DNA by forming bonds between the sugar and phosphate groups, while the nitrogenous bases extend from the backbone and pair up to maintain the structure of the double helix.