The individuality of an organism is determined by the organisms
A. Nitrogen base sequence
B. The order of the phosphates and sugars
C. Polymers
D. Amino acids
The Correct Answer and Explanation is:
The correct answer is A. Nitrogen base sequence.
Explanation:
The individuality of an organism is largely determined by its genetic code, which is encoded in DNA. DNA is composed of four nitrogenous bases: adenine (A), thymine (T), cytosine (C), and guanine (G). The unique sequence or arrangement of these nitrogen bases is what defines an organism’s specific genetic instructions and, ultimately, its individual traits.
Each sequence of nitrogen bases forms genes, which carry the information needed to create proteins. Proteins are the building blocks of an organism, responsible for functions such as structural support, enzyme reactions, and cellular signaling. Every gene has a specific sequence that codes for a particular protein, and these proteins influence traits like eye color, height, metabolism, and susceptibility to certain diseases.
To understand why the nitrogen base sequence is so crucial, it helps to look at the process of protein synthesis. DNA sequences are transcribed into messenger RNA (mRNA), which carries the code from the nucleus to ribosomes in the cell. Here, the mRNA is translated into a specific chain of amino acids, creating a protein. The sequence of amino acids in the protein (determined by the nitrogen base sequence in the DNA) dictates the protein’s structure and function, which in turn contributes to the organism’s phenotype, or observable characteristics.
Other options in the question play roles in DNA structure but don’t directly determine individuality. For example:
- B. The order of the phosphates and sugars refers to the DNA backbone, which provides structure and stability but doesn’t carry genetic information.
- C. Polymers are large molecules, such as DNA itself, made of repeating units. However, they do not define individuality because it’s the specific sequence of units that matters, not the fact that DNA is a polymer.
- D. Amino acids are the building blocks of proteins, and while they determine protein function, they are coded by the DNA sequence, so they are not the root source of individuality.
In summary, it is the unique sequence of nitrogen bases in DNA that contains the information determining each organism’s individuality, setting the genetic foundation for all inherited traits.