Bryophytes Flashcards
what are the different divisions of the Kingdom plantae
1) Bryophytes (non-vascular)
2) pteridophytes (seedless vascular)
3) gymnosperms and angiosperms (vascular)
What are the different divisions/ phyla of bryophytes
1) mosses
2) liverworts
3) hornworts
what era did bryophytes evolve
paleozic era (500 million years ago)
what are the different leaf shapes of a bryophte
1) thalloid
2) leafy
describe what is meant by Acrocarpous and pleurocarpous moss
Acrocarpous- mosses with an upright growth habit
pleurocarpus- feathery with a sprawling growth habit
what is meant by a heteromorphic alteration of generations
a life cycle which exhibits an alteration of two distinct generations
1) gametophyte (haploid gen)
2) sporophyte (diploid gen)
what generation is dominant in bryophytes
the gametophyte generation
what is a gametophyte
any organism in its haploid phase of life
what is a sporophyte
any organism in its diploid stage of life which produce archegonia and antheridia
in mosses what does the sporophyte generation consist of
a seta and a capsule
what is a archegonia
a female multicellular structure which produces a haploid egg
what is an antheridia
a male multicellular structure which produces haploid sperm
what is meant when a gametophyte is described as bisexual
both archegonia and antheridia are produced on the same individual plant
what is meant when a gametophyte is described as dioecious
when an individual is either male or female not both
outline how the sporophyte generation is formed in mosses
1) the haploid egg is fertilised by the haploid sperm producing a diploid zygote (sporophyte) which develops in an embryo within the archegonia (on the gametophyte)
2) the embryo grows and differentiates producing a diploid sporophyte consisting of an absorptive foot, seta and capsule
3) within the capsule 2n cells undergo meiosis producing tetrads of haploid spores (gametophytes)
