Bio 2 Exam 3

PLANTS (& hormones)

Flowering Plants (phyta)

Anthophyta

• monocots

• eudicots

Conifers (phyta)

coniferophyta

Gnetophytes (phyta)

gnetophyta

cycads (phyta)

cycadophyta

Ginkgo (maiden hair trees) (phyta)

ginkgophyta

ferns, wiskferns, and horsetails (phyta)

monilophyta

lycophytes (phyta)

lycophyta

liverworts (phyta)

hepatophyta

mosses (phyta)

bryophyta

hornworts (phyta)

anthocerophyta

factors for plants evolving to land

• photosynthetic bacteria and algae begin with increasing O2

• plants and fungi were first on land

• directly related to green algae, Charophytes

plant characteristics

• photosynthetic

• alternation of generations

• generally fixed in the environment

• use growth to find and acquire resources

impact of cell walls

• limit a plants ability to move

• contribute to plant structure

• maintain turgor pressure

• thicker cell walls with cellulose or lignin

• allow plants to have vascular tissues

alternation of generations (general)

• sporophytes (2n) have sporangia

• sporangia produce (meiosis) spores (n)

• spores disperse

• spores grow into gametophytes (n)

• gametophytes have gametangia

  • archangia (n)(eggs)

  • antherridia (n)(sperm)

  • made through mitosis

• fertilization

• zygote

• zygote develops into sporophyte

sporopollenin

allows a spore to survive in environment once dispersed

apical meristems

meristems - areas of rapidly dividing cells

primary growth - roots and shoots

secondary growth - woody plants grow in girth

(plants grow from their tips)

cuticle

waxy covering that limits water loss and CO2 uptake

stomata

• stoma + guard cells

• for regulation of gases entering and exiting the leaf

four major evolutionary transformations

1. alternation of generations and embryos

2. vascular tissue (xylem and phloem)

3. seeds and pollen

4. fruits and flowers

xylem

move water and nutrients from the roots (dead cells)

phloem

moves photosynthate (carbs) to the rest of plant (living cells)

bryophyte characteristics

• Don’t have roots

  • hairlike structures anchor it

• dominant gametophyte phase

• sporophyte is dependent on gametophyte

• swimming sperm

• leaves are called microphylls

• mosses, hornworts, liverworts

• cannot regulate water loss

• gemmae cups for asexual reproduction

• epiphytes

seedless vascular plants

• ferns, horsetails, wiskferns,club/spike mosses

• vascular tissue

• rhizoids to roots

• megaphyll leaves

• sporophyte dominant

• ferns unroll into fiddleheads

• wiskferns: dichotomous branching

ferns

• distinctive leaves

• stems are underground

horsetails

• whorls of leaves

• silica in cell walls

• stems are hollow

seed plant characteristics

• do not require external water for reproduction

• male gametophyte is transported in pollen

• seeds enhance dispersal

• nutrient-rich tissue in the seeds makes it more likely that the plant embryo will grow

  • surrounds embryo

  • life pod

• seeds can be dormant longer than spores

• ovule leads to formation of seed

gymnosperms (plant groups)

• cycads

• ginkgos

• conifers

• gnetophytes

factors contributing to angiosperm diversity:

• flowers that attract a variety of animal pollinators

• plants with animal pollinators can reproduce even if they’re far apart, allowing rare species to persist and reproduce

eudicots

• majority of angiosperms

• two embryonic cotyledons

• woody trees, herbaceous plants, water-storing cacti, and most parasitic and carnivorous plants

• flower organs in multiples of 4 or 5

• highly conductive xylem (can support high rates of photosynthesis)

• crowns with spreading branches, reducing competition for light and space

• net-veined

• vascular bundles arranged in rings

monocots

• single cotyledon

• large variety in shape and size

• in almost every vegetative environment

• important in diets

• do not form vascular cambium

• stems contain the vascular bundles scattered throughout the cross section

• limited in growth (height and width)

• flower organs in multiples of 3

• parallel leaf veins

crop plants

• genetic diversity is important

  • makes less susceptible to pathogens