PSYCH 2H03 Lecture Notes - Weaning, Constipation, Kilogram
Document Summary
Most cells of the body have a full set of 46 chromosomes, while the gametes each have half that number 23 chromosomes. The first 22 pairs of chromosomes are called autosomes, the chromosomes in each pair are about the same size. In the 23rd pair the x chromosome is much larger than the y and are known as the sex chromosomes. An egg always carries an x chromosome while a sperm can carry either a x or. Each chromosome consits of one molecule of dna. Each group of nucleotide bases that provides a specific set of biochemical instructions is called a gene. The sperm and egg may come from prospective parents but are sometimes provided by donors. Occasionally the fertilized egg may be placed in the uterus of a surrogate mother. Only about 1/3 of ivf succeed and so many couple will thus go through multiple attempts at fertilization. Genes and environment work tgoether and affect one another.