AP BIOLOGY

Detailed explanation-1: -The correct answer is (A) DNA. DNA is a nucleic acid used to store genetic information within cells. The sequence of DNA nucleotides encodes information that can be used to make proteins. These proteins are responsible for the traits of an organism.

Detailed explanation-2: -The expressed traits are a result of the specific genotypic combination of the alleles, which are a pair of genes . Also, a particular gene codes for a specific protein that determines the physical characteristics of an individual. This is how genes control the traits.

Detailed explanation-3: -The nucleotides are covalently linked together in a chain through the sugars and phosphates, which thus form a “backbone” of alternating sugar-phosphate-sugar-phosphate (see Figure 4-3).

Detailed explanation-4: -In turn, this pattern of arrangement ultimately determines each organism’s unique characteristics, thanks to another set of molecules that “read” the pattern and stimulate the chemical and physical processes it calls for.