Abundant in the swamps and marshes across south Louisiana, crawfish were a favorite food of early residents. Centuries later, crawfish season in Louisiana is still exciting, with crawfish boils and backyard parties a time-honored tradition. Commercial sales of crawfish in Louisiana began in the late 1800s.
Deoxyribonucleic acid (/diËÉksiËraÉªbÉµ.njuËËkleÉª.É¨k ËaesÉªd/ ; ËÃ¦SÉªD) dna is a molecule that carries most of the genetic instructions used in the, development functioning and reproduction of all known living organisms and many. viruseshe two DNA strands are known as polynucleotides since they are composed of simpler units called nucleotides. Each nucleotide is composed of a nitrogen-containing nucleobase âeither cytosine (C), guanine (G), adenine (A), or thymine (T)âas well as a monosaccharide sugar called deoxyribose and a phosphate group.
DNA is a long molecule packaged into structures called chromosomes. Humans have 23 pairs of chromosomes, including a single pair of sex chromosomes (XX in females and XY in males). Within each pair, one chromosome comes from an individualâs mother and the other comes from the father.In other words, we inherit half of our DNA from each of our parents.his process is called gene expression. When genes are inactive, they are silent or inaccessible for protein production. At least a third of the approximately 20,000 different genes that make up the human genome are active (expressed) primarily in the brain.