- Slides: 9
Domain Eukarya Kingdom Protista Kingdom Fungi Kingdom Plantae Most unicellular, some colonial Mostly multicellular, all heterotrophs (yeast = unicellular) Multicellular autotrophs (photosynthesis) Lack strong tissue development Aqueous, marine, or very humid environments Obligate symbionts Chlorophyll Cell walls contain chitin Cell walls contain cellulose Hyphae, mycelium Nonmotile Found in air, water, & terrestrial habitats Adapted for life on land Decomposers Alternation of generations
Review Haploid: having 1/2 the number of chromosomes. Diploid: having a full complement of chromosomes (2 n). Meiosis: cell division where chromosome number is reduced from diploid to haploid. Fertilization: nuclei of two gametes fuse, raising the chromosome number from haploid to diploid.
Your life cycle: · You are diploid. · Your cells produce haploid gametes through meiosis. · Your gametes fuse with someone else’s to form a diploid zygote. · The zygote differentiates by mitosis into a multicellular, diploid individual.
Plants have two generations in their life cycle: • Gametophyte: haploid, gamete-producing phase. • Sporophyte: diploid spore-producing phase.
In plants, generations alternate: (Sporophyte) • A diploid individual produces haploid spores by meiosis. • Spores divide by mitosis, producing multicellular haploid gametophytes (e. g. Pollen grain). • Gametophytes produce gametes that fuse to form a diploid zygote. • Zygotes differentiate by mitosis into multicellular, diploid individuals. (Sporophytes)
Plants are grouped by: • morphology • +/- & arrangement of vascular tissues (xylem & phloem) • life cycle
Kingdom Plantae Phylum Bryophyta (Mosses, liverworts, hornworts) No vascular tissues Restricted in size and by habitat Gametophyte = dominant phase Ferns & allies + vascular tissues Seedless Sporophyte = dominant phase Phylum Gymnosperma (Conifers, cycads, ginkgos, gnetophytes) + vascular tissues Heterosporous: m/f cones Sporophyte = dominant phase Phylum Anthophytha (Angiosperms, or flowering plants) + vascular tissues Speciose, mutualisms, short generation times Sporophyte = dominant phase
Angiosperms Dicots # Floral parts # Cotyledons Leaf venation Stem vascular bundles Secondary growth Monocots
Complete Flowers (monoecious) • Bisexual or hermaphroditic Incomplete Flowers (dioecious) • Staminate (male) • Pistilate (female)