PSYC 251 Chapter Notes - Chapter 2: Assisted Reproductive Technology, In Vitro Fertilisation, Allosome
12 Mar 2014
School
Department
Course
Professor
Document Summary
Page 44-63, 20 pages page 1 of 4. The biology of heredity: there are 200-500 million sperm in the 5ml of semen ejaculate; of these, a few hundred reach the fallopian tubes. The 23rd pair of sex chromosomes determine the sex of the child, with x much larger than y. The egg contributes an x, and the sperm"s contribution (x or y) determine the sex, with the y chromosome initiating a male pattern of development: each chromosome is one molecule of deoxyribonucleic acid (dna). A group of nucleotide bases provide a set of biochemical instructions as a gene: the complete set of 25,000 genes make up a person"s heredity, or genotype. These genetic instructions, in conjunction with environmental influences, produce a phenotype the observable expression of genotype in an individual"s physical, behavioural, and psychological features: only identical twins are genetically identical.
