Bryophytes Flashcards
what are the three phyla/ divisions of bryophytes
1) mosses
2) liverworts
3) hornworts
what are the general characteristics of bryophytes
- small
- no flowers
- no pollen produced
- grow in most conditions other than aquatic
when did bryophytes evolve
Paleozic era
500 million years ago
what is meant by the term heteromorphic alterations of generations
there are two generations within a life cycle which are morphologically and genetically different
1) gametophyte (haploid gen)
2) sporophyte (diploid gen)
outline the structure a bryophyte may have
1) leafy
2) thalloid
what is a bryophyte
a simple, non- vascular plant comprised of mosses, liverworts and hornworts
what is the difference between the terms acrocarpous and pleurocarpous
acro= having the sporophyte capsules at the tips with a upright growth habit
pleuro= bearing sporophyte capsules along central stem between the leaves
what is the dominant generation in the bryophyte life cycle
gametophyte generation as the sporophyte generation is dependent on the gametophyte
define gametangia
a specialised organ or cell which produces gametes
what are the male and female gametes of bryophytes
antheridia= male
archegonia= female
what is an archegonium
the female sex organ
outline how the sporophyte generation is formed
1) fertilisation of the egg cell and sperm forms a diploid zygote which develops in the archegonium
2) the embryo differentiates producing a diploid sporophyte
what does a mature sporophyte consist of
1) absorptive foot
2) seta
3) capsule
what is a sporophyte
the diploid phase in which produces spores form which gametophytes arise
outline the structure of the sporophyte capsule
= presence of a lid which breaks off revealing the peristome teeth
= these teeth regulate the release of spores by opening and closing in response to humidity
outline the structure of antheridia
- spherical and elongated
- presence of a sterile jacket which surrounds sperm producing cells
outline the structure of archegonia
- swollen basal portion is known as the ventre which holds a single egg cell
- portective sterile jacket
- egg is matrophically nourished
what do sperm cells need in order to be moltile
water
what characteristics do all plants have
- eukaryotic
- cells with plastids
- photoautotrophic
- cell wall
what are the different kingdom of plantae
1) bryophytes
2) pteridophytes
3) gymnosperms and angiosperms
define sporangium
the receptacle in which asexual spores are formed
