LIFESCI 1 Lecture Notes - Lecture 4: Green Algae, Ordovician, Carboniferous
Document Summary
Haploid (n) = 1 set of chromosomes. Diploid (2n) = 2 sets of chromosomes. Humans have 2n 46 chromosomes total. Many multicellular protists have a multicellular haploid phase and a multicellular diploid phase. In kelp both the sporophyte and gametophyte are multicellular. Green algae is closely related to land plants. Same photosynthetic pigments, chloropyll a and b. Each era is separated by a mass extinction and then a time period for new life forms to take over. More co2 on land because they are primary producers. Might be other resources that are available to plant. Cuticle the waxy layer that protects from desiccation. Pores with stomata and guard cells help conserve water. Having pores and cuticles are really important adaptations in transitioning to land. Simple water conducting cells in say a moss, which have evolved into more complicated cells with lignin rings in them so plants can grow up more rigid. Lingin is the defining feature of vascular plants.
