Kingdom Plantae

Kingdom PlantaeAlgae

RhodophytaPhaeophytaChlorophyta

Bryophytes (Mosses) Tracheophytes (Ferns)Gymnosperms (Conifers)Angiosperms (Flowers)

Plant CharacteristicsEukaryotic (nucleus & organelles)Autotrophic – PhotosynthesisCell walls contain celluloseReproduce via alternation of

generations

Plant Cell

PhotosynthesisSugar producing chemical reaction

occurring in chloroplastsThylakoid – Membranous structures

increase surface area for reaction to occur

Evolution of Plants

Evolution of PlantsEarliest ancestors – Plant like protists (single celled algae)Multicellular green algae is the ancestor to modern

terrestrial plantsTrend in plant evolution is adaptation to life on land

More access to sunlight – foodChallenges of terrestrial life:

DesiccationStructural supportReproduction (motile sperm)Respiration (gas exchange without water loss)Availability of required nutrients (N & K)Temperature fluctuation

Alternation of GenerationsDuring life cycle plant switches back and forth between the sporophyte and gametophyte generations (they alternate)2 phases:1. Sporophyte generation = diploid

(2N) & produces spores by meiosis.2. Gametophyte generation = haploid

(N) & produces gametes (sex cells).

AlgaeUnicellular Algae – Kingdom ProtistaMulticellular Algae – Kingdom

PlantaePhylum Rhodophyta (red)Phylum Chlorophyta (green)Phylum Phaeophyta (brown)

AlgaeNon-Vascular – No transport system

to move water and nutrients around plant

Seedless – No protective covering around developing embryo

Algae must life in aquatic or moist environments

Asexual Reproduction in Algae1. Fragmentation – piece

breaks off and grows into a new individual

2. Asexual spores – haploid

3. Mitotic division – simple cell division (some by meiosis)

Sexual Reproduction in AlgaeThe two gametes fuse to form a zygote

There are 2 types of gametes:1. Isogamy – identical gametes or isogametes –

same size & structure. When isogametes fuse = conjugation. Isogametes are differentiated by + and – sign (like fungus)

2. Heterogamy – gametes differ in size & structure (heterogametes). Larger, female= egg; smaller, male = sperm. When egg & sperm fuse = fertilization

Alternation of Generations in Algae

Snow AlgaeArticle and Questions