Which sentence best describes a gene? A. A gene is part of the cell membrane B. A gene is a complete protein C. A gene is a segment of a DNA strand D. A gene is a segment of a protein
The Correct Answer and Explanation is:
Correct Answer: C. A gene is a segment of a DNA strand
Explanation
A gene is a specific segment of a DNA strand that contains the instructions for making proteins or RNA molecules. DNA, or deoxyribonucleic acid, is the hereditary material found in the cells of all living organisms. It is composed of four chemical bases—adenine, thymine, cytosine, and guanine—arranged in sequences that code for genetic information. These sequences are grouped into genes, which serve as blueprints for the synthesis of proteins that carry out various functions in the body.
Each gene provides the code needed to build a particular protein or to regulate biological processes. This process begins with transcription, where the DNA sequence of a gene is copied into messenger RNA (mRNA). The mRNA then carries this information to the ribosome, the site of protein synthesis. In a process called translation, the ribosome reads the mRNA sequence and assembles the appropriate amino acids to form a protein.
Genes vary in length and can be made up of thousands of DNA bases. While not all DNA sequences are genes, genes are the functional units that determine traits such as eye color, blood type, and susceptibility to certain diseases. Genes are inherited from one’s parents, and they reside on chromosomes within the nucleus of each cell.
The other answer choices are incorrect for the following reasons: Option A is incorrect because a gene is not part of the cell membrane. Option B is incorrect because a gene is not a protein itself but a set of instructions to make a protein. Option D is incorrect because proteins are made from genes, not the other way around.
In summary, a gene is best described as a segment of a DNA strand that codes for a specific function, often the production of a protein.
