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A hereditary carrier ( genetic carrier or just carrier ), is a person or other organism that has inherited a recessive allele for a genetic trait or mutation but usually does not display that trait or show symptoms of the disease. Carriers are, however, able to pass the allele onto their offspring, who may then express the genetic trait.
Genes are pieces of hereditary material that are passed from parents to offspring. Genes are part of cell structures called chromosomes. In multicellular organisms, chromosomes are found in the nucleus of the cell. Each of these chromosomes contains one, long molecule of DNA, or d eoxyribo n ucleic a cid.
Today, most scientists agree that genes correspond to one or more DNA sequences that carry the coding information required to produce a specific protein, and that protein in turn carries out a...
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Review your understanding of genes, proteins, and traits in this free article aligned to NGSS standards.
•Genes are specific stretches of a chromosome’s DNA molecule. DNA molecules are made up of smaller parts called nucleotides. So, a gene is a specific stretch of nucleotides within a chromosome’s DNA.
•DNA is made up of four types of nucleotides. These nucleotides are often called by their shortened names: A, C, T, and G (which stand for adenine, cytosine, thymine, and guanine). The nucleotides in a gene are connected in a specific order.
•Proteins are molecules that carry out many different functions in cells. For example, some proteins provide structure for the cell. Others help carry out chemical reactions.
•Proteins are made up of smaller parts called amino acids. The amino acids in a protein are also connected in a specific order. A protein’s amino acids determine its 3D structure and its function.
•The cell builds proteins using instructions found in genes. Specifically, the order of nucleotides in a gene determines the order of amino acids in one or more proteins.
•An organism has many different genes, and so can produce many different proteins. These proteins have functions that affect the organism’s traits.
5 days ago · gene, unit of hereditary information that occupies a fixed position (locus) on a chromosome. Genes achieve their effects by directing the synthesis of proteins. In eukaryotes (such as animals, plants, and fungi ), genes are contained within the cell nucleus.
- The Editors of Encyclopaedia Britannica
Jul 31, 2022 · When they inherit one recessive X-linked mutant allele and one dominant X-linked wild-type allele, they are carriers of the trait and are typically unaffected. Carrier females can manifest mild forms of the trait due to the inactivation of the dominant allele located on one of the X chromosomes.
The genes of every cell on Earth are made of DNA, and insights into the relationship between DNA and genes have come from experiments in a wide variety of organisms. We then consider how genes and other important segments of DNA are arranged on the long molecules of DNA that are present in chromosomes.
