BIOL 102 Lecture 16: Meiosis
Document Summary
Most accurate de nition of reproduction: production of one autonomous organism from another. Coral don"t have genetic diversity; they have large areas that are genetically identical; in risk for global warming because they have low genetic diversity. Typical human cell has 46 chromosomes, 44 autosomes, and 2 sex chromosomes. Sex of embryo of certain species depend on environment; ex. warmth of nest, timing of birth in season. Connection between light and temperature is signal transduction; genes can detect the change. Ex. parrot sh start out as females and grow up to be male. Simultaneous hermaphrodites: organisms give sperm to one another; impregnate one another. If change in sex ratio persist, population will decline. If change in sex ratio is short term, it doesn"t matter that much. Homogametic: a pair of homologous x chromosomes. Heterogametic: one x and one y chromosome. In class of 200 unrelated people, with equal # of males and females, there are 300 unique x chromosomes.
