Final answer:
A gene is a section of DNA that contains the code for making a specific protein, and it’s a fundamental unit of heredity. Genes contribute to the traits an organism displays, and the collection of all an organism’s genes is known as its genome. The genetic code within genes is used during transcription to create proteins.
Step-by-step explanation:
A gene is the section of DNA in an organism's genome that encodes instructions for a particular trait. It is the basic unit of heredity that is passed from parent to child.
Genes are made up of sequences of nucleotides in DNA, providing the code necessary for the synthesis of specific proteins. These proteins lead to the expression of physical characteristics or traits. The genome is the entire genetic complement (including all genes) of an organism, and changes or variations in the gene sequences contribute to biodiversity and evolution.
The genetic code within a gene works as a series of three-letter codes that specify which amino acids will be added next during protein synthesis. This process, where RNA is created based on the DNA template, is known as transcription. In genome sequencing, researchers map the order of the nucleotides to understand an organism’s complete set of genetic instructions.