BIOL 2107 Lecture Notes - Lecture 6: G2 Phase, Nucleolus, Interphase
Document Summary
Hypothesized that the joining of semen and egg would cause fertilization. Direct observation of fertilization between egg and sperm (between frog and sea urchin) Conclusion: something in nucleus must contain hereditary material. Long thread like bodies (chromosomes) visualized in nucleus. Movement of these bodies followed through cell division. 2 kinds of cell division; mitosis and meiosis. Mitosis: nucleus divides and generates 2 daughter cells containing same number of cells as parental cells somatic cells (body cells) Meiosis: production of gametes (sperm/eggs) each containing half the number of chromosomes (as you get 1 set from mom and 1 set from dad) Most cells are diploid (each chromosome par has one maternal and one paternal copy) . Meiosis = haploid cells are produced which only have 1 copy and depending on if organism is male or female determines whether gametes are sperm or eggs. Union of haploid (single pair of chromosomes) sperm and egg come together to produce a diploid cell.
