Tree of Life – Plants
Slide One –
•Bryophytes AKA Mosses
•Typically very small / inconspicuous
•Compare bryophyte life cycle to others
Slide Two –
Slide Three –
•Eukaryotic Plants
Slide Four/Five/Six –
•Green algae are the evolutionary predecessors of plants
Slide Seven –
•Bryophytes are represented by four main branches of plants
oLiverworts
oTwo Mosses
oHornworts
•Bryophytes don’t fossilize very well
Slide Eight –
•Angiosperms – Largest
•Bryophytes – Second Largest
•Ferns - Inbetween
•Lycophytes – Second Smallest
•Gymnosperms – Smallest
Slide Nine – liverworts
•Flattened bodies
oGrow right on top of soil
oGrow reproductive structures (umbrella-like)
Male – Antheridia
Female - Archegonium
Slide Ten – mosses
•Largest group within bryophytes
•Flattened and small
•Grow in cushion packs or more spread out in groups
Slide Eleven – hornworts
•Main body is similar to liverworts
•Don’t grow umbrella-like structures but rather horns
Slide Twelve – generalized alternation of generations
•Lifecycle perspective
oContains two generations
First generation consists of sperm and egg which are haploid
Fertilization leads to doubling of chromosomes
Diploid generation undergoes mitosis from zygote to embryo and
again into sporophytes
Sporophytes undergo meiosis into individual spores (reduction)
Mitosis again into gametophyte
oMosses have haploid lifecycle dominance
oFlowering plants and Gymnosperms have diploid lifecycle dominance
Slide Thirteen – lifecycle of bryophytes
•Male gametophyte has a cup-shaped organ which contain antheridia which
contain spermatozoids (haploid)
•Female gametophyte has a flask like structure which accepts the spermatozoid
(having only a single egg cell)