CSD-4662 Lecture 2: Basic Concepts of Genetics

• School: App State
• Department: Communication Sciences and Disorders
• Course: CSD-4662
• Professor: Benjamin A.Russell

Document Summary

Genetics: basic concepts, genetics is the science of heredity, which explains how organisms receive traits from previous generations, dna (deoxyribonucleic acid) is the molecule that carries genetic information, together with other instructions for operating the organism. Involves abnormal gene on an autosomal chromosome: all the chromosomes except for the sex chromosomes, defect occurs if the child receives one (or two) copies of the abnormal gene. If 1 parent carries one abnormal chromosome, and the other parent is totally normal (not a carrier), child has: 50% chance normal, 50% chance defect, autosomal recessive. If both parents are carriers (each with one an abnormal resessive gene), child has: 25% chance normal, 50% chance carrier, 25% chance defect. If only one parent is a carrier, child has: 50% chance totally normal, 50% chance carrier, x-linked recessive, aka sex-linked recessive. In males there is only one x chromosome, therefore, a single abnormal gene on that chromosome will cause the defect.