Plant Classification

Alternation of generations Sporophyte (diploid) Begins when sperm fertilizes egg (zygote) Diploid zygote divides by mitosis to create a mature sporophyte Meiosis produces haploid cells called spores Haploid spores released

Alternation of generations Gametophyte (haploid) Begins with spores created by meiosis Spore grows into gametophyte Male gametophyte creates sperms Female gametophyte creates eggs Sperm & egg create diploid zygote (process repeats)

Group 1: Seedless, Nonvascular Plants Live in moist environments Liverworts Hornworts Mosses

Mosses Nonvascular, seedless Grow low to ground to retain moisture Lack true leaves Leaf-like structures only 1 cell thick Rhizoids anchor into soil Early inhabitant of new ecosystems (succession)

Moss Life Cycle Gametophyte phase Sporophyte phase Dominant stage Carpet of moss growing near ground Archegonium: produces female egg Antheridium: produces male sperm Sperm swims through water to fertilize egg Sporophyte phase Stalk grows up from the gametophyte Sporangia houses haploid spores Spores land and new gametophyte grows Moss Life Cycle See appendix B in your text book

. . . . . 1) Moss gametophytes grow near the ground (haploid stage) 2) Through water, sperm from the male gametophyte will swim to the female gametophyte to create a diploid zygote 3) Diploid sporophyte will grow from the gametophyte where the zygote is located 4) Sporophyte will create and release haploid spores . . . . . sporophyte gametophyte

. . . . . 5) Spores land and grow into new gametophytes 6) The process repeats . . . . . ground gametophyte

Plant Life Cycle Comparisons Plant type Sporophyte Gametophyte Dominant? Moss Stalk with cup (capsule) at tip, which is where spores are produced. More familiar, carpet-like plant that produces specialized gametes GAMETOPHYTE Fern More familiar, leafy plant with clusters of spore producing sacs (sori) Haploid plant body (prothallus) is size of a finger nail, produces both male and female parts SPOROPHYTE Conifer More familiar- like pine trees, produces male and female cones that produce spores Pollen grains are male gametophytes sperm, female gameotphytes are microscopic eggs

Group 2: Seedless, Vascular Plants Vascular system allows nutrient transport to greater heights Club mosses Horsetails Ferns

Ferns Seedless, vascular plants Vascular: allows taller growth Rhizoids: underground stems draw nutrients Fronds: leaves uncurl sporangia on underside Sori: clusters of sporangia

Fern Life Cycle Sporophyte phase Gametophyte phase Dominant stage Sporangia produces haploid spores Spores released into air Gametophyte phase Spore grows into prothallus Archegonium: produces female egg Antheridium: produces male sperm Sperm swims to egg Zygote begins sporophyte stage See appendix B in your text book

. . . . 1) Sporophyte creates and releases haploid spores Adult Sporophyte (diploid) ground

2) Spores land in the soil . . . . ground

3) From the haploid spores, a prothallus (haploid gametophyte) grows in the soil -- Rhizoids anchor Let’s zoom in ground

4) Sperm swim through water from the antheridium to the archegonia Let’s zoom back out

5) Diploid sporophyte (fiddlehead) grows from the prothallus -- prothallus eventually dies ground

. . . . 6) Fiddlehead uncurls into fronds of ferns. 7) Cycle repeats -- Sporangia creates spores to be released . . . . ground

Plant Life Cycle Comparisons Plant type Sporophyte Gametophyte Dominant? Moss Stalk with cup (capsule) at tip, which is where spores are produced. More familiar, carpet-like plant that produces specialized gametes GAMETOPHYTE Fern More familiar, leafy plant with clusters of spore producing sacs (sori) Haploid plant body (prothallus) is size of a finger nail, produces both male and female parts SPOROPHYTE Conifer More familiar- like pine trees, produces male and female cones that produce spores Pollen grains are male gametophytes sperm, female gameotphytes are microscopic eggs