Biology test 3

• Eukaryotes
• Primarily photoautotrophs
• Primarily terrestrial
• Radially symmetrical
• Apical-basal polarity=grows up&down simultaneously
• Organized
• Reproduce sexually via alternation of generations
• Descendants of algae
• Kingdom Plantae

• Physical laws and the environment constrain the size and shape of organisms
• Form and function are correlated at all levels of organization
• Energy is used to sustain form and function
• Internal environments are regulated

• Sexual reproduction of a plant
• 2 forms of a plant
• Generations are gametophytes(N) that produce gametes and sporophytes(2N) that produce spores
• Nuclei fusion of gametes-->zygotes-->cleavage-->embryo
• Go from diploid to haploid, meiosis

Sporophytes

• Gametophytes are haploid
• Sporophytes are diploid

• A vascular plant has ducts or vessels where sap is
• conveyed through the plant.
• Has a vascular system, that transports water/sugars.

• Angiosperms(flowering plants) produce fruits to protect seeds, gymnosperms(firs, pines, spruce) don't.
• They both contain vascualr cylinders, cotyledons, and meristem.

• RAM&SAM
• Primary growth&primary tissues
• Tips of root
• Stem of plants, leaves, and branches

• Secondary growth
• Increases in girth(width)
• Woody species

• Gives rise to cork
• Layer of cells, bark
• Secondary meristem

• Gives rise to secondary xylem (wood) and secondary phloem
• Divides in 2 directions- inside&outside
• Secondar phloem=outside, periphery

• Anchorage
• Absorption(water&minerals form soil)
• Transport of water and minerals up to shoot&sugars from shoot to root
• Storage of sugar(sucrose) and starches
• Production of long distance chemical signals(hormones)
• Also can take up oxygen from air pockets in soil

• Photosynthesis(leaves&stems)
• Sexual reproduction(flowers&fruits)
• Transport of water, minerals, and sugars to and from roots
• Storage of sugar(sucrose) and starches
• Production of hormones

• Stems in non-woody plants, continuation of epidermis, cortex, and vascular cylinder of roots
• Structures=primary xylem, pith, secondary xylem, vascular cambium, secondary phloem, remains of primary&secondary phloem, cork cambium, and cork.

Cuticle&epidermis=suberin(primary component, wax, prevents dessication), guard cells(pairs, controls open&closing of stomata, in cuticle), stomata(gases exchanged, guard cells with this).

Mesophyll(most ground tissue)=palisade(upper layer, rows) and spongy(bottom, less organized, air spaces allow for water vapor)

Vascular cylinders visible as veins, provides support, also transport of water&other materials, surrounded by bundle sheath.

Petiole attaches stem w/ leaf. Positions leaf in place(vertical) and connects vascular tissues of leaf with stem.

Long distance chemical signals

dermal(outer covering of plant), vascular, & ground (ground tissue includes everything that's not dermal or vascular)

• Parenchyma- Composed of least specialized plant cells. Cell walls are thinnest and most flexible. Photosynthesis&storage of organic products
• Collenchyma- Columns or cylinders support young parts of plants in a flexible manner so growth can occur
• Sclerenchyma-Thickest cell walls of all three

Thin-walled cells are called parenchyma cells; collenchyma cells have slightly thicker walls, and sclerenchyma cells are very rigid

The stem will have an epidermis without root hairs, cortex, vascular tissues arranged in a ring of vascular bundles or a solid cylinder of vascular tisses. The phloem will be towards the outside and the xylem to the inside. There is a pith in the center of the stem.

• Blade-photosynthesis
• Cuticle-prevents dessication
• Guard cells-pair, controls opening and closing of stomata
• Stomata-exchange gases

• palisade= upper layer, rows of cells, photosynthesis&stores organic products
• Petiole=positions leaf, connects vascular tissues
• spongy=photosynthesis&stores organic products&accumulates water vapor

• Seed to seed lifetimes
• Annual=takes one year to grow from seed to fruition and die
• Biennial=takes two years to grow from seed to fruition and die
• Perennial=Lasts a long time

• Epidermis=outermost layer, protrusions have extra surface area
• Endodermis=single layer of cells at the innermost layer of cortex, protective barrier around vascular tissue

• Cotyledon=leaf like structure that absorbs nutrients from the endosperm and provides it to the embryonic plant during germination
• Monocot=one seed leaf
• Dicot=two seed leaves

• Determinate=individual stops growing at a certain age/size
• Indeterminate=individual that grows throughout lifetime(lizard, fish)

• Example: slicing a pie
• Not bi-lateral

• Xylem conducts water up through the plant(tracheids&vessel elements)
• Phloem moves sugar through the plant in 2 directions(sieve tube members&companion cells)

• Xylem-dead b/c of pits
• Has perforations, pits, and tapering ends.
• Tracheids=long&slender
• Vessel elements=short&broader

• Phloem-alive, lacks organelles, hollow
• Sieve tube members-long&rectangular w/ sieve structures @ the end
• Companion cells-life support systems for sieve tubes, transports sucrose for energy

• Pericycle=outermost layer of vascular tissues
• Cork=outer bark
• Pith=innermost portion, inactive

• Woody plants, apart of vascular cambium
• Divides in 2 directions, inside and outside
• Secondary phloem=outside, periphery
• Secondary xylem=wood
• Secondary growth is formed by secondary lateral meristem.

The types of ground tissue found in plants develop from ground tissue meristem and consists of three simple tissues: Parenchyma, Collenchyma, and Sclerenchyma

• Internodes-the part of a plant stem between two nodes
• Meristem-region of plant tissue consisting of actively dividing cells forming new tissue
• Nodes-area of a plant's stem from which the leaves grow
• Veins-xylem&phloem present here, transports water&sugar
• Fiber cells-sclerenchyma, more of these in roots

• Transport by individual cells, the uptake&loss of water and solutes by individual cells(root hairs)
• Short distance transport from cell to cell at the levels of tissues and organs(sugar from leaf to phloem)
• Long distance transport of water and solutes(sap) within xylem and phloem throughout the plant involves bulk flow

Plant cells have cell walls, which animal cells lack. This means that there is a structure that the intracellular fluid can push against. Turgor pressure and water potential are instrumental in helping hold non-woody plants upright and in the transport of sucrose in the phloem.

• Plasma membranes regulate the transport of solutes and water in and out of cells(selective permeability)
• Transport proteins allow ions and polar molecules to pass through plasma membranes
• Proton pumps-most significant active transports, sets gradient, allows plasma membranes to store energy
• Central vacuole&its membrane(tonoplast)- tonoplast contains proton pumps like plasma membrane

• Aquaporins-facilitate diffusion of water, channel protein, also transport protein
• Sap-water&solutes
• Turgor pressure-result of osmotic pressure(pressure required to prevent osmosis), pressure within a cell that results from movement of water into cell
• Water potential- physical property that predicts which way water will flow. Determined by solutes&applied pressure. High to low

• 3 routes- transmembrane, symplast, apoplast
• Symplast-continuity of cytosol. Cytosol to plasmodesmata to cytosol, etc.
• Apoplast- continuity of cell walls, materials only moving from cell wall to cell wall not crossing plasma membranes and not controlled by plant
• Transmembrane-moves particular things, flows in and out repeatedly

• Movement of materials from soil into plant are associated with differences in concentrations.
• Minerals are water soluble, they are actively transported into plant via symplastic&apoplastic
• Increasing minerals in cytoplasm of root hairs, materials diffuse from epidermis to pericycle

Flaccid- when cells lose water and wilt