Chapter 4 Vocabulary: Alternation of Generations

Mitosis

division of a parent cell into two daughter cells of the same ploidy

Meiosis

division of a diploid parent cell into four haploid daughter cells

Alternation of generations

a life cycle in which organisms alternate between haploid gametophyte and diploid sporophyte generations

Ulva

a chlorophyte green alga sometimes called "sea lettuce;" exhibits isomorphic alternation of generations

Spore

a haploid cell covered in a resistant sporopollenin coating; divides mitotically to produce a gametophyte

Gamete

a haploid cell produced by the gametophyte; fuses with another gamete to create a zygote

Gametophyte

the haploid generation in plants and some algae; produces gametes by mitosis

Sporophyte

the diploid generation in plants and some algae; produces spores by meosis

Zygote

the diploid cell created by fusion of two gametes; divides mitotically to form a sporophyte

Fertilization

the fusion of two gametes to produyce a zygote

Isomorphic

describes an organism in which the haploid and diploid generations appear identical

Heteromorphic

describes an organism in which the haploid and diploid generations are different in appearance

Gametangium

cell layer or organ in which gametes are produced

Sporangium

cell layer or organ in which spores are produced

Spore germination

the mitotic division of a spore to produce a mature gametophyte

Archegonium

gametangium that produces eggs

Antheridium

gametangium that produces sperm

Bryophytes

the seedless nonvascular plants, including mosses, liverworts and hornworts

Sporopollenin

a highly resistant chemical coating found in the zygotes of charaophyte algae and on the outside of spores in land plants

Protonema

the filamentous branching structure created in the early stages of moss spore germination