test 3 Flashcards
what evidence shows that plants are related to green algae
evidence for this includes chemical and structural similarities, like the chloroplasts of plants and green algae contain the same photosynthetic pigments; in addition, like green algae, plants have cellulose-rich cell walls and use starch as a nutrient reserve, as well as similar DNA sequences
what group of green algae are plants most closely related to
charophyte
describe the challenges of a terrestrial existence that plants had to overcome
air provides less physical support than water and dries out the stem and leaves
four main groups of land plants
bryophytes, seedless vascular plants, gymnosperms, and angiosperms
cuticle and stomata
bryophytes
xylem and phloem
vascular plants
pollen and seeds
gymnosperms
flowers and fruits
angiosperms
coats leaves and stems, preventing water loss
cuticle
structure in leaves that permit gas exchange
stomata
how are materials transported in different types of plants
in bryophytes, they use cell-to-cell diffusion and in other plants they use vascular tissue (xylem and phloem)
significance of xylem and phloem
both are vascular tissue used for transportation; the xylem conducts water and dissolved minerals from the roots to the leaves and the phloem transports sugars produced in photosynthesis to the roots and other nongreen parts of the plants
_______ is a complex polymer that strengthens cell walls, the additional support from this polymer means that vascular plants can grow tall and form branches which is an important adaptation to sunlight
lignin
a plants life cycle; a multicellular diploid stage alternates with a multicellular haploid stage
alternation of generations
_____________ is the diploid generation in the alternation of generations; this is where some cells undergo meiosis and produce haploid spores that divide mitotically to form _________
sporophyte; gametophyte
____________ is the haploid generation in the alternation of generations; produces gametes by mitotic cell division, these sex cells fuse at fertilization which results in the first zygote of the next ______________ generation
gametophyte; sporophyte
bryophyte’s size and independence relative to the gametophyte and sporophyte generations
sporophyte: size relative to sporophyte -> varies ; depends on sporophyte for nutrition -> no
gametophyte: size relative to gametophyte -> varies ; depends on gametophyte for nutrition -> yes
vascular plants’ size and independence relative to the gametophyte and sporophyte generations
sporophyte: size relative to sporophyte -> small ; depends on sporophyte for nutrition -> no
gametophyte: size relative to gametophyte -> large ; depends on gametophyte for nutrition -> no
gymnosperms’ size and independence relative to the gametophyte and sporophyte generations
sporophyte: size relative to sporophyte -> microscopic ; depends on sporophyte for nutrition -> yes
gametophyte: size relative to gametophyte -> large ; depends on gametophyte for nutrition -> no
angiosperms size and independence relative to the gametophyte and sporophyte generations
sporophyte: size relative to sporophyte -> microscopic ; depends on sporophyte for nutrition -> yes
gametophyte: size relative to gametophyte -> large ; depends on gametophyte for nutrition -> no
haploid cells that develop into the gametophyte generation (present in all plant life cycles)
spores
a plant embryo and its food supply, packaged inside a seed coat; produced by gymnosperms and angiosperms
seed
male gametophyte of a seed plant; carried by wind or animals, eliminating the ned for moisture in reproduction
pollen grain
angiosperm structure that produces pollen and egg cells; the site of fertilization
flower
seed-containing structure that is unique to angiosperms; develops from flower parts after fertilization
fruit
seedless plants that lack vascular tissue, evidence suggests they do not form a single clade
bryophytes
the function of rhizoids for bryophytes
cover a bryophyte’s lower surface, anchoring the plant to its substrate; rhizoids cannot tap distant sources of water so many of these species are restricted to moist, shady habitats
what are the three phyla of bryophytes
liverworts, hornworts, and mosses
bryophyte phylum that has a variety of gametophyte forms, from flat to upright and leafy; they may be the bryophytes most closely related to ancestral land plants
liverworts
bryophyte phylum which is the smallest group of bryophytes, with only about 100 species; they are named for their sporophytes, which are shaped like tapered horns
hornworts
bryophyte phylum that is the closest living relative to vascular plans, the gametophytes resemble short “stems” with many “leaves”
mosses
how do bryophytes affect ecosystems
they play important roles; mosses can survive on bare rock or in a very thin layer of soil, as their tissues die they contribute organic matter, helping build soil that larger plants subsequently colonize
_______ are small pieces of tissue that detach and grow into new plants and it is where asexual production in liverworts occur; made up of a _______ cup and _______ inside of the cup
gemmae; gemma (2)
in the sexual life cycle of a _______, the sporophyte is a stalk attached to the gametophyte, at the tip of the stalk there are specialized cells inside a sporangium that undergo meiosis and produce haploid spores; after these spores are released, they germinate, giving rise to new haploid gametophytes; gametes forms by mitosis in separate sperm- and egg-producing structures, then sperm swim to the egg cell in a film of water that coats the plants (sexual reproduction for this phylum require water)
sexual life cycle of moss
what are the means of dispersal for mosses
windblown spores are the main means of dispersion, the earliest evidence of plants on land is a fossilized bryophyte spore
these types of plants have true roots, stems, and leaves; in many species, the leaves and roots arise from the underground stems (rhizomes); these plants are also reasonably taller and wider
seedless vascular plants
the two phyla of seedless vascular plants
Lycopodiophyta and Pteridophyta
describe Lycopodiophyta and give examples
club mosses; small plants that have simple leaves that resemble scales or needles, their name reflects their club-shaped reproductive features (closely related to spike mosses)
what are the three lineages of Pteridophyta
whisk ferns, horsetails, true ferns
(Pteridophyta lineage) simple plants that have rhizomes but not roots, most species have no obvious leaves
whisk ferns
(Pteridophyta lineage) grow along streams or at the borders of forests, the only living genus of this lineage includes plants with branched rhizomes that give rise to green aerial stems bearing spores at their tips (stems and leaves contain abrasive silica particles)
horsetails
(Pteridophyta lineage) make up the largest group of seedless vascular plants (11,000 species) the fronds (leaves) of this lineage are their most obvious feature, and their remains form most coal deposits
true ferns
which generation of a fern life cycle is the only generation containing vascular tissue
sporophyte
(life cycle of a type of Pteridophyta) the sporophyte produces haploid spores by meiosis in collections of sporangia on the underside of each frond; once shed, the spores germinate and develop into tiny, heart-shaped gametophytes that produce gametes by mitotic cell division; the swimming sperm require a film of water to reach an egg cell, the gametes fuse, forming a zygote and this diploid cell divides mitotically and forms the sporophyte, which quickly dwarfs the gametophyte
life cycle of fern
first seed plants; the seeds of these plants are “naked” because they are not enclosed in fruits
gymnosperms
what are the four phyla of gymnosperms
cycads, ginkgo, conifers (pinophyta), and gnetophytes
(gymnosperm phyla) this phylum lives in primarily tropical and subtropical regions, they have palmlike leaves, and they produce large cones; they dominated Mesozoic era landscapes and today they are popular ornamental plants
cycads
(gymnosperm phyla) maidenhair tree; has distinctive, fan-shaped leaves; only one species exists “biloba” but it no longer grows wild in nature, though it is a popular cultivated tree; they have male and female organs on separate plants; female trees have fleshy seeds that produce a foul odor
ginkgo
(gymnosperm phyla) pine trees are a part of this phylum; often have needlelike or scalelike leaves, they produce egg cells and pollen in cones; commonly called “evergreens” because most retain their leaves all year
conifers
(gymnosperm phyla) include some odd plants like Welwitschia, a desert plant with a single pair of large, strap-shaped leaves that persist throughout its life
gnetophytes
each _______ cone scale bears two ovules on its upper surface, these produce the ______ reproductive cells (and eventually develop into seeds); inside ovule there is a sporangium that undergoes meiosis and produces four haploid megaspores, only one of which develops into a ______ gametophyte; over many months this gametophyte gives rise to 2-6 egg cells (this all happens at the same time as the other sex’s cones develop)
female
______ cones bear sporangia on thin, delicate scales; through meiosis, these sporangia produce microspores, which eventually become windblown pollen grains
male
the role of ______ in the conifer life cycle is being an egg-bearing structure that develops into a seed in gymnosperms and angiosperms
ovule
flowering plants; flowers and fruits are the reproductive structures that are unique to these plants; the plants’ flowers produce pollen and egg cells; after pollination and fertilization, flowers develop into fruits that enclose the plants’ seeds
angiosperms
