Moss Life Cycle

Alternation of generations Zygote created from egg & sperm

Alternation of generations Zygote divides by mitosis to create adult sporophyte

Alternation of generations Haploid spores created by meiosis

Alternation of generations Haploid spores released into air

Alternation of generations Female gametophyte creates eggs Male gametophyte creates sperm Spore grows into male or female gametophyte

Alternation of generations Sperm & egg create diploid zygote

Alternation of generations Cycle repeats

Group 1: Seedless, Nonvascular Plants Most primitive of plants Live in moist environments –S–Swimming sperm Examples: –L–Liverworts –H–Hornworts –M–Mosses

Mosses Because nonvascular: Grow low to ground –W–Water transported by simple diffusion Lack true leaves –o–only 1 cell thick Rhizoids anchor into soil Early inhabitant of new ecosystems (succession)

Moss Life Cycle Gametophyte stage –Dominant stage; Haploid –Looks like mat of green shag carpet

Moss Life Cycle Gametophyte stage –Dominant stage; Haploid –Looks like mat of green shag carpet Antheridium: produces male sperm Male gametophyte (creates sperm)

Moss Life Cycle Gametophyte stage –Dominant stage; Haploid –Looks like mat of green shag carpet Antheridium: produces male sperm Archegonium: produces female egg Male gametophyte (creates sperm) Female gametophyte (creates eggs)

Moss Life Cycle Gametophyte stage –Dominant stage; Haploid –Looks like mat of green shag carpet Antheridium: produces male sperm Archegonium: produces female egg –Sperm swims through water to fertilize egg Male gametophyte (creates sperm) Female gametophyte (creates eggs)

Moss Life Cycle Gametophyte stage –Dominant stage; Haploid –Looks like mat of green shag carpet Antheridium: produces male sperm Archegonium: produces female egg –Sperm swims through water to fertilize egg Male gametophyte (creates sperm) Female gametophyte (creates eggs) zygote

Moss Life Cycle Male gametophyte (creates sperm) Female gametophyte (creates eggs) zygote stalk Gametophyte stage –Dominant stage; Haploid –Looks like mat of green shag carpet Antheridium: produces male sperm Archegonium: produces female egg –Sperm swims through water to fertilize egg Sporophyte stage –Stalk grows out of the zygote

Moss Life Cycle Male gametophyte (creates sperm) Female gametophyte (creates eggs) zygote capsule stalk Gametophyte stage –Dominant stage; Haploid –Looks like mat of green shag carpet Antheridium: produces male sperm Archegonium: produces female egg –Sperm swims through water to fertilize egg Sporophyte stage –Stalk grows out of the zygote –Haploid spores created inside capsule by meiosis

Moss Life Cycle Male gametophyte (creates sperm) Female gametophyte (creates eggs) zygote capsule stalk Gametophyte stage –Dominant stage; Haploid –Looks like mat of green shag carpet Antheridium: produces male sperm Archegonium: produces female egg –Sperm swims through water to fertilize egg Sporophyte stage –Stalk grows out of the zygote –Haploid spores created inside capsule by meiosis –Spores released and grow into new gametophytes.....

Moss Life Cycle See appendix B in your text book Male gametophyte (creates sperm) Female gametophyte (creates eggs) zygote capsule stalk Male gametophyte (creates sperm) Female gametophyte (creates eggs)..

Moss Life Cycle See appendix B in your text book Male gametophyte (creates sperm) Female gametophyte (creates eggs) zygote capsule stalk Male gametophyte (creates sperm) Female gametophyte (creates eggs)

Moss Life Cycle See appendix B in your text book Male gametophyte (creates sperm) Female gametophyte (creates eggs) zygote capsule stalk Male gametophyte (creates sperm) Female gametophyte (creates eggs)

Moss Life Cycle See appendix B in your text book Male gametophyte (creates sperm) Female gametophyte (creates eggs) zygote capsule stalk Male gametophyte (creates sperm) Female gametophyte (creates eggs)

Moss Life Cycle Male gametophyte (creates sperm) Female gametophyte (creates eggs) zygote capsule stalk Male gametophyte (creates sperm) Female gametophyte (creates eggs) zygote sporophyte

Moss Life Cycle Male gametophyte (creates sperm) Female gametophyte (creates eggs) zygote capsule stalk Male gametophyte (creates sperm) Female gametophyte (creates eggs) sporophyte....

Moss Life Cycle

Place the steps of the moss life cycle in order, from the step started for you: __ 1___ Spores land. _______ Diploid sporophyte will grow from zygote. _______ Through water, sperm swim from antheridium (male gametophyte) to archegonium (female gametophyte). _______ Moss gametophytes grow near the ground. _______ Sporophyte will create and release spores. _______ Fertilization occurs

Plant Life Cycle Comparisons Plant typeSporophyteGametophyteDominant? MossStalk with cup (capsule) at tip, which is where spores are produced. More familiar, carpet-like plant that produces specialized gametes GAMETOPHYTE FernMore 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 ConiferMore familiar- like pine trees, produces male and female cones that produce spores Pollen grains are male gametophytes  sperm, female gameotphytes are microscopic  eggs SPOROPHYTE

Review 1)Label the parts of the diagram. 2)Using the picture answer the following: Where are spores created? Name the haploid stage. Which grows from the zygote? 3)How are the antheridia and archegonia different? Similar? 4)Meiosis begins which stage of plants? 5)Fertilization begins which stage of plants? 6)How are haploid spores created?