While looking at a cell under a microscope, a scientist is able to see a biological molecule. This molecule is a nucleic acid with a ladder structure and contains the nitrogenous bases adenine, thymine, cytosine, and guanine. Based on this information, what conclusion can the scientist draw regarding this nucleic acid?

Based on the information , the scientist concluded that the regarding nucleic acid is  DNA (Deoxyribonucleic Acid) .The structure of DNA is attached below -:

Explanation:

PROPERTIES OF DNA -

In humans and almost all other species, DNA, or deoxyribonucleic acid, is an inherited substance. Almost every cell in the body of an individual has the same DNA. The DNA information is stored as a code consisting of four chemical bases: adenine (A), cytosine ( C), guanine ( G) and thymine ( T). In order to form units called base pairs, DNA bases pair up with each other, A with T and C with G. A sugar molecule and a phosphate molecule are both affixed to each base. Together, a nucleotide is called a base, sugar , and phosphate. Two long strands are arranged with nucleotides that form a spiral called a double helix. The double helix structure is much like a ladder, with the base pairs forming the rungs of the ladder and the molecules of sugar and phosphate forming the vertical sidepieces of the ladder.An significant DNA property is that it can duplicate itself or create copies of it. In the double helix, each strand of DNA will serve as a template for duplicating the sequence of bases. As each new cell requires to have an exact copy of the DNA present in the old cell, this is important as cells divide.

Hence, the structure identified and conclude by the scientist is DNA (deoxyribonucleic acid). Thus, the structure of DNA is attached below.