Plant kingdom diversity

Plant groups  Bryophytes (seedless, non-vascular)  Seedless vascular plants  Gymnosperms  Angiosperms

Cladogram Bryophytes Green algae Seedless vascular plants GymnospermsAngiosperms Evolution of specialized cells / tissue Evolution of cuticle

Bryophytes  think moss

Bryophytes  Small  Found only in damp, moist areas on land  1) Leaves must touch water for photosynthesis  2) Sperm swims through water to reach egg in gametophyte

Bryophytes gametophyte sporophyte

Alternation of generations Multicellular diploid organism (2n) Unicellular haploid cells (n) meiosis Unicellular diploid zygote (2n) mitosis (spores) Multicellular haploid organism (n) mitosis Unicellular haploid gametes (n) fertilization sporophyte gametophyte mitosis

Cladogram Bryophytes Green algae Seedless vascular plants Gymnosperms Angiosperms Evolution of specialized cells / tissue Evolution of cuticle Evolution of vascular tissue

Vascular tissue  Set of tubes that transport materials around plant  Allows plants to grow taller  Water travels up through xylem  Sugar travels throughout in phloem

Seedless vascular plants  Think ferns

Ferns live further on land  Still must be in moist areas  Sporophyte survives fine with vascular tissue  But sperm must still swim to egg in tiny gametophyte

Fern gametophyte

Cladogram Bryophytes Green algae Seedless vascular plants Gymnosperms Angiosperms Evolution of specialized cells / tissue Evolution of cuticle Evolution of vascular tissue Evolution of pollen grains / seeds

Pollen grains  Hard covering around sperm, light weight allows travel by wind  Removes water requirement for fertilization

Sperm still swims  At the very end when pollen lands on another plant of same species  Pollen tube connects to ovary, sperm swim to egg

Full colonization of land  Vascular tissue  +  Reproduction through air

Seeds  Tough coat protects newly fertilized embryo  Also contains supply of food (endosperm) to survive during dormancy period

Gymnosperms  Think cones (any conifer like pine trees) female ovary male pollen cone

Gymnosperm pollen strategy  Release a lot, hope some pollinate  (Meanwhile, irritating everyone else)

Cladogram Bryophytes Green algae Seedless vascular plants Gymnosperms Angiosperms Evolution of specialized cells / tissue Evolution of cuticle Evolution of vascular tissue Evolution of pollen grains / seeds Evolution of flowers / fruits

Angiosperms  Think flowers (most diverse plant group)

Flowers  Attract animals to help carry pollen to the next flower  Color or scent attractors guide animals to obtain sugar from plant  Oh, and while you’re at it, grab some pollen  Some angiosperms still wind pollinate (grass)

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After fertilization, ovary becomes fruit

Fruit  Typically collects sugar to attract animals  Seeds survive animal digestive system, pooped out far away from parent (and with free fertilizer!)  Some are not eaten by animals, just help wind carry seed (dandelion)

Asexual reproduction  Plants can also reproduce asexually  Many plant parts can regrow to make a whole new organism when separated (vegetative reproduction)

Cladogram Bryophytes Green algae Seedless vascular plants Gymnosperms Angiosperms Evolution of specialized cells / tissue Evolution of cuticle Evolution of vascular tissue Evolution of pollen grains / seeds Evolution of flowers / fruits