final exam notes - labs 7, 8, 9, & 10

Lab 7 - Seed Plan Diversity

Introduction:

  • vascular tissue - xylem and phloem

    • transport water, minerals, and nutrients long distances

    • structural support

Plant Growth:

  • primary - vertical (all plants)

  • secondary - width growth (seed plants)

  • wood and bark are made of vascular tissue

  • sporophyte dominant in ferns, gymnosperms, and angiosperms

  • reduced gametophyte

  • seeds - protective case for embryo, disperse to better conditions which contributes to more diversity

Pollen and Pollination:

  • pollen - male gametophyte

  • pollination - transfer of pollen to egg

    • removes need for water in fertilization

Life Cycle:

  • have female and male spores (mega and microspores)

  • spores don’t leave sporophyte

Gymnosperms:

  • no fruit seeds, no flowers, have conifers (cycads, ginkgos)

Conifers:

  • evergreen, everything you can see is sporophyte, gametes in cone

  • cone - reproductive structure with scales

  • female and male cones (ovulate and pollen)

    • pollen - each scale has microsporangia (2n), microsporocytes do meiosis

    • ovulate - each scale has megasporangia (2n) aka ovule

  • pollination, fertilization, and seed development happen at different times

    • female - yr 1 is pollination, yr 2 egg produced and fertilization to produce zygote, yr 3 zygote becomes embryo

Seed Components:

  • coat - protect, devwlops from megasporangium/ovule

  • nutritive tissue - food, develops from megagametophyte

  • embryo

Angiosperms:

  • have flowers

  • reproductive structures for pollination and fertilization

  • flowers enclose seeds in fruits

Flower Anatomy:

  • pistil/carpel - contains ovary

  • ovary - enlarged part of pistil/carpel where ovules are produced

  • anther

  • filament

  • stamen

  • perform double fertilization

    • 1 sperm fertilizes egg, makes zygote

    • other sperm fertilizes central cell, makes endosperm (zygote food)

  • fruit develops from ovary

Lab 8 - Plant Structure

Introduction:

  • leaf - large surface area for photosynthesis

  • bud - undeveloped tissue that becomes leaves, branches, flowers

    • apical - tip/apex

    • axillary - armpit

  • shoots - photosynthesis and reproduction

  • roots - water, nutrients, anchor plants

Growth:

  • indeterminate - dont stop growing

  • meristems - plant growth and division site

    • apical - leads to primary growth, happens at tips of stems/roots

    • lateral - secondary growth, form wood and bark

    • root apical meristem - primordial is newly developed structures, areas of cell division have dark staining

Tissues:

  • cell walls have cellulose

  • primary cell wall

    • all plants, thin, expands during cell growth

  • secondary cell wall

    • some plants, inside primary cell wall,thick/many layers of cellulose and ligmin, strong and rigid, don’t grow with cell

  • central vacuole

    • stores water/molecules, maintains shape by exerting pressure

  • simple tissue - 1 cell type

  • complex tissue - more than one cell type

Parenchyma:

  • basic cell type - all come from parenchyma

  • cell is alive and large, thin primary cell wall

  • function - storage and photosynthesis

Collenchyma:

  • cell is alive, unevenly thick primary cell wall

  • function - flexible support of growing stems and leaves

Sclerenchyma:

  • provide support and structure

  • very thick secondary cell wall

  • dead when mature

  • 2 shapes - sclereids (polygon in fruit/nut) and fibers (elongated in stems)

Tissue:

  • 3 complex tissue systems based on function/position

  • dermal, vascular, ground

  • arranged different in root, stem, and leaf

  • dermal - protection, single or multiple layers, parenchyma is main cell type

  • epidermis - stomata open for gas exchange and guard cells can open and close stoma

  • vascular - internal transport, 2 types (xylem and phloem)

    • xylem - transport water and minerals, thick secondary cell wall, cells are dead

    • phloem - transport sugar produced by photosynthesis, alive but no nucleus or ribosomes, have companions to make proteins

  • ground - storage, support, and metabolism

Lab 9 - Fungi

Introduction:

  • eukaryotes, 1 kingdom, heterotrophs, more related to animals than plants

  • digest food externally

    • secrete enzymes that break down food, nutrients are absorbed

  • most are saprotrophs - eat dead

    • decomposers

  • some eat living organisms

    • parasites, mutualists, predators

  • made of hyphae

  • mycelium - mass of hyphae

    • make up fungus, underground feeding part

  • fruiting body - reproduction,, called the mushroom

    • most are multicellular

  • hyphae made of chains of cells

    • walls made of chitin (carb)

    • walls have opening, allow for exchange of materials

  • unicellular fungi - yeast

    • ferment sugars for energy, produce alcohol and carbon dioxide

  • 3 fungal phyla that are important

  • sexual reproduction happens in bad conditions

  • plasmogamy - cytoplasm of different mating types fuse

    • nuclei still separate

    • called heterokaryotic stage (n + n) - hyphae have nuclei from different parents

  • karyogamy - fuse nuclei to form zygote