PSYC 363 Lecture Notes - Lecture 2: Primitive Streak, Prenatal Development, Neural Tube
Document Summary
Beginning of life: begins with dna that contains chemical instructions for cells to create various proteins (promotes growth and sustains life. : chromosomes: molecules of dna, consists of 46 chromosomes, 23 pairs. Gametes: reproductive cells (sperm and ova) each has 23 chromosomes. Zygote: when 2 gametes combine and produce a new individual with 23 chromosomes from each parent. Allele: 2 forms of each gene that occurs at the same place on the chromosomes, one inherited from the other and one from the father. Autosomes: 22 of 23 closely matched human chromosomes. Can be inherited by a male or female: 23rd pair: xx and xy. Monozygotic (identical twins): originate from one zygote that splits apart very early in development: same genotype but slight variations in phenotype, possible due to environment. Dizygotic (fraternal twins): woman release 2 eggs, both get fertilized by separate sperm. They have their genes in common and occur twice as often as monozygotic twins.
