PSYB20H3 Lecture Notes - Parasitic Disease, Spina Bifida, Universal Health Care
Document Summary
Directly observable characteristics are called phenotypes, which depend in part on the individual"s genotype the complex blend of genetic information that determines our species and influences all our unique characteristics. Phenotypes are also affected by environmental influences ones that begin even before conception. The question of how nature and nurture work together to shape the course of development. People are made up of trillions of units called cells. Within every cell is a control center, or nucleus, that contains rodlike structures called chromosomes, which store and transmit genetic information. Chromosomes come in 23 matching pairs (an exception is the xy pair in males) One is inherited from the mother and one from the father. Chromosomes are made up of deoxyribonucleic acid, or dna, which is a long double-stranded molecule that looks like a twisted ladder. Each rung of the ladder consists of a pair of chemical substances called bases.
