BI111 Lecture Notes - Lecture 3: Plant Evolution, Green Algae, Plant Reproduction
Document Summary
Chloroplasts contain chlorophyll a, b ( green pigments) and carotenoids (orange and red pigments) Plants transitioned to land 425 million years ago. Gas exchange takes place through stomata (pores) on surface of leaves. Leaves covered with waxy cuticle to prevent desiccation(state of extreme dryness) *have xylem (water flow) and phloem (food flow) Gametophyte (n - haploid): a mature haploid male or female germ cell that is able to unite with another of the opposite sex in sexual reproduction to form a zygote. Sporophyte (2n - diploid): is the diploid multicellular stage. It develops from the zygote produced when a haploid egg cell is fertilized by a haploid sperm and each sporophyte cell therefore has a double set of chromosomes, one set from each parent. Bryophytes (true mosses) have a large gametophyte stage. Other plants have a large sporophyte stage. Nonvascular plants include liverworts, hornworts, and mosses. Nonvascular plants are low-growing, reproduce with spores, and need a moist habitat.
