Question

What will happen to the expression of a particular trait if a gene gets altered?

Answer 1

A phenotypic trait is the expression of genes in an observable fashion, and it is an evident, observable, and measurable trait. A certain hair colour or eye colour is an example of a phenotypic characteristic. The hair colour is determined by underlying genes, which make up the genotype, but the hair colour observed is the phenotypic.

Complete solution:
Genes are little pieces of genetic material found on chromosomes. They code for mRNA molecules, which are RNA molecules that code for certain proteins. This protein manifests as a phenotypic trait or as a metabolite that contributes to the function of a metabolic system.
Gene expression is frequently altered as a result of mutations in an organism's genetic makeup. This change could cause a gene to be silenced, have its expression reduced, or have its expression increased. Diseases are frequently observed as a result of such changes.
Healthy persons have an unusually high number of mutations in their DNA. It's common knowledge that everyone has flaws in their DNA, albeit the flaws are usually innocuous. Instead of having an all-or-nothing look, a continuous trait has a range of expression (such as weight, height). Continuous qualities are frequently polygenic and have a lot of environmental effects on how they are expressed.
A dominant allele is the gene that controls the expression of a trait. Genes are divided into alleles, which are distinct variations of the same gene. Every gene in somatic cells has two alleles, one contributed by each of the organism's parents.

Note:
A gene that is not ordinarily expressed in that cell can be turned on and expressed in large amounts. This can occur as a result of gene mutations or regulatory alterations in genes ( epigenetic, transcription, post-transcription, translation, or post-translation).A dominant allele is a gene that controls the expression of a trait. Alleles are different types of genes that come in different combinations. Every gene in somatic cells has two alleles, one from each of the organism's parents.