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4. Development is characterized by lifelong plasticity4
Chapter 3 Biological Beginnings (Genetic foundations)What is a gene & what does it code for? Define DNA, chromosome, allele.Gene: a segment of DNA that codes for synthesis of a proteinsoFound in the cell’s nucleus as part of a chromosomeoProtein enzymes are the body’s tools (synthesize, breakdown, change)The protein a cell has determines its functionoGenes hold the instructions for building proteinsDoes NOT code for behaviorDNA: blue print, the master plan for the bodyoPassed from parents to offspringoTwo copies of each gene, one from each parentoDouble helix structureoA particular sequence of nucleotide pairs Adenine – Thymine; Guanine – CytosineEvery 3 rungs of this is an amino acidChromosome: a threadlike structure made largely of DNA molecules wound tightly around clumps of proteinsoHumans have 23 pairs of chromosomes, 46 in totaloThe 23rd chromosome is the sex chromosomeGirl: XX Boy: XYAllele: various forms of a particular gene (may be several), options for a particular form of a gene, variants are allelesoExample: eye color--- many options, such a green, blue, brown, etc.