ch. 27 - seedless plants
#8 on study guide. fertilization occurs at stage ___ of this cycle
4
what is the purpose of the waxy cuticle in plants
It prevents desiccation
what is the male sexual structure that produces sperm in plants?
antheridium
plants are believed to have evolved from which group of algae
charophytes
which is a characteristic shared between green algae and plants
chlorophylls a and b in plastids
alternation of generations in plants refers to the alternation of
diploid and haploid stages
the leafy fern that you might have as a house plant is the _____ generation
diploid sporophyte
in plants, the fertilized egg develops into a multicellular ______(young plant) within a female gametangium
embryo
mosses have stems, roots, and leaves
false
each archegonium produces many eggs
false- a single egg
if a plant produces microspores and megaspores, then by definition, it is homosporous
false- heterosporous
xylem is a vascular tissue that conducts dissolved sugars
false- water and dissolved minerals
which of the following is a vascular plant
fern
the sori of most ferns are found on which part of the plant
fronds
what are the multicellular sex organs in plants
gametangia
the ____ generation is dominant in mosses, as it can live independently
haploid gametophyte
many seedless plants produce spores of one morphological type, which is referred to as
homospory
a key step in the evolution of vascular plants was the ability to produce _____, a strengthening polymer in the walls of cells that function for support and conduction
lignin
the oldest known fossils suggest that the _____ may have been the first plants to inhabit land
liverworts
describe alternation of generations
plants alternate between a haploid gametophyte and a diploid sporophyte. the dominant form varies; the gametophyte is dominant in the mosses, and the sporophyte is dominant in the ferns, gymnosperms, and angiosperms
the gametophyte generation of ferns is the
prothallus
when a moss spore lands in a suitable spot, it germinates and grows into a filament of cells called a
protonema
heterospory is believed to have led to the evolution of
seeds
what do ferns lack
seeds
which is the most economically important bryophyte
sphagnum
after sexual reproduction in a moss, the _____ grows out of the gametophyte
sporophyte
discuss adaptions for terrestrial life seen in land plants
stomata to allow carbon dioxide to enter the leaf; a waxy cuticle to reduce water loss; gametangia with sterile cells to protect the reproductive cells; lessened reliance on water for reproduction
why are mosses and liverworts limited in size
they lack vascular tissues
modern botanists think that all plants evolved from a common ancestor that was an ancient green algae. what is the best explanation for this hypothesis
they share many biochemical and metabolic traits
in algae, gametangia are generally unicellular
true
which vascular tissue is responsible for conducting water and dissolved minerals in plants
xylem
