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

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 Swimming sperm Examples: Liverworts Hornworts Mosses

Mosses Because nonvascular: Grow low to ground Lack true leaves Water transported by simple diffusion Lack true leaves 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 zygote Male gametophyte (creates sperm) Female gametophyte (creates eggs)

Moss Life Cycle Gametophyte stage Sporophyte 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 stalk zygote Male gametophyte (creates sperm) Female gametophyte (creates eggs)

Moss Life Cycle Gametophyte stage Sporophyte 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 capsule stalk zygote Male gametophyte (creates sperm) Female gametophyte (creates eggs)

Moss Life Cycle Gametophyte stage Sporophyte 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 capsule stalk . . . . . zygote Male gametophyte (creates sperm) Female gametophyte (creates eggs)

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

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

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

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

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

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

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.

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