BIOL 111 Lecture Notes - Lecture 5: Phloem, Xylem, Sporophyte

• School: McGill University
• Department: Biology
• Course: BIOL 111
• Professor: Rudiger Krahe

Document Summary

Biol 111 lecture 5 evolution of land plants. Lecture date/time: sept 24nd, 2015 / 10:35-11:25 am. Plants living in water maintain these needs by: no water deficiency = full hydration, gametes can be released into water, so no protection is needed. Universal phenomenon: alternation of generations in sexually reproducing organisms. Each species has a particular genetic composition. There is specificity at the species level, so to keep it constant, there must be some process where genetic capacity is kept constant so it doesn"t go wrong. Haploid form called gametophyte (=each cell has one set of chromosomes) alternates with a diploid form called sporophyte (=each cell has 2 sets of chromosomes) & thus maintains the constancy of genetic material, by not doubling it/halving it. Gametophyte produces gametes that fuse to form the zygote develops into a sporophyte, which forms haploid spores through meiosis, then each spore develops into a gametophyte (male or female)