Lab Quiz 3 on Plants
Why is it beneficial to have the sporophyte generation dominant in plants?
The sporophyte generation has vascular tissues.
Why are Chara called stoneworts?
They are covered with Calcium Carbonate deposits
Chara
filamentous green algae that consist of a primary branch and many side branches.
In the human life cycle meiosis occurs during the production of
gametes
Cytoplasmic division in plants is
cell plate formation
Cell walls are made of
cellulose for support and protection
Most of them are:
photoautotrophs, so they contain chloroplasts
Fronds arise from an underground horizontal stem called a
rhizome
Fern can spread out without
sexual reproduction
Fern spores are produced by meiosis in structures called
sporangia
In the plant life cycle, meiosis occurs during the production of
spores
Liverwort Marchantia sp.
- Simple plants without roots or vascular systems. - Marchantia thallus shows differentiation into two layers: an upper photosynthetic and a lower storage region with a well defined upper epidermis with air channels (barrel-shaped). - It features tiny cup like structures called gemmae cups, which is used for asexual reproduction.
Fern Morphology
- Sporophytes have rhizomes. - Fronds (leaves) develop at the tip of the rhizome as tightly rolled-up coils. -They unroll and expand.
Plants have a haplodiplontic life cycle:
-Multicellular diploid stage = Sporophyte. -Multicellular haploid stage = Gametophyte.
Ferns - Pterophytes
-The most abundant group of seedless vascular plants with about 11,000 species. The conspicuous sporophyte and much smaller gametophyte are both photosynthetic. The fern life cycle differs from that of a moss: -Much greater development, independence and dominance of the fern's sporophyte.
Bryophytes
1) Nonvascular plants include the mosses, liverworts, and hornworts (grouped together called bryophytes). 2) Gametophyte is dominant in all bryophytes. 3) Gametophyte produces eggs within archegonia and flagellated sperm in antheridia. 4) Nonvascular sporophyte grows out of the archegonium. 5) Sporophyte is dependent on the female gametophyte.
Land plants have two major features:
1. Protected embryos. 2. Multicellular haploid and diploid phases.
Adaptations to Terrestrial Life
1. Protection from desiccation by a waxy cuticle and stomata. 2. Evolution of leaves which increase photosynthetic surface area. 3. Shift to a dominant vertical diploid generation.
What characteristics cause Chara to resemble land plants?
Appearance, protects the zygote
Adaptations to Terrestrial Life
As more complex plants evolved: a. Diploid stage became the dominant portion of the life cycle. b. Gametophyte became more limited in size. c. Sporophyte became nutritionally independent.
How is the gametophyte generation in ferns similar to that of mosses? How is it different (aside from appearance)?
Both produce flagellated sperm, and neither has vascular tissue in the gametophyte. The gametophyte generation is dominant in the moss, but is separate and short-lived in the fern.
Lycophytes
Commonly called club mosses. First vascular plants that have roots, stems, and leaves. Leaves are called microphylls (have only one strand of vascular tissue).
In the human life cycle, the individual that produces gametes is (n or 2n)
Diploid (2n)
Is the sporophyte haploid or diploid?
Diploid (2n)
Classification of Plants
Gymnosperms - Naked Seeds Angiosperms - Flowers/Ovaries
What is the chromosome number (choose 2n or n) of the sperm? Are the surrounding cells haploid or diploid?
Haploid (n) Haploid (n)
What is the chromosome number of the egg? Are the surrounding cells haploid or diploid?
Haploid (n) Haploid (n)
When spores germinate, what generation begins to develop?
Haploid gametophyte
____________ is a shelflike structure that protects the sporangia until they are mature.
Indusium
How does Chara superficially resemble a land plant?
It has a stem and branches
Describe the appearance of a living moss gametophyte or a plastomount of this generation.
It has a stemlike structure covered with whorls of leaflike structures.
Spike Moss - Salaginella
Lives in the desert of Western Texas. Resurrection plant.
By what process are the spores being produced?
Meiosis
Fern Reproduction
Most fern are homosporous -Produce distinctive sporangia in clusters called sori on the back of the fronds -Diploid spore mother cells in sporangia produce haploid spores by meiosis -At maturity, the spores are catapulted by snapping action
Are seedless vascular plants fully adapted to living on land?
No. They have flagellated sperm which swim to the egg in external moisture.
Psilotum
Psilotum is a tropical whisk fern. Lacks roots and leaves. Root function is performed by a stem that grows underground and symbiotic endomycorrhizal fungi that absorb water and minerals. Leaf function is carried out by a photosynthetic stem.
What does Chara feel like?
Rough
What is being produced inside the antheridium? When sperm produced by the antheridia swim to the archegonium in a film of water, what results?
Sperm. Fertilization occurs, resulting in a zygote.
Plant Life Cycle
Sporophyte produces haploid spores by meiosis. Spores divide mitotically, producing the gametophyte. Gametophyte produces gametes by mitosis. Gametes fuse to form the diploid sporophyte.
This structure develops into what generation?
Sporophyte that becomes independent of the gametophyte.
Storage polysaccharide
Starch
Label Gametophyte and Sporophyte
The gametophyte (n) is the leafy shoot portion; the sporophyte (2n) is the capsule and stalk.
Compare and contrast moss and fern sporophytes.
The moss sporophyte, a stalk and capsule, is dependent on the gametophyte, which is the dominant generation. The fern sporophyte, the leafy frond, is independent and the dominant generation. Fern sporophyte has vascular tissue and true roots, stems, and leaves.
Why is it proper to say that spores are dispersal agents?
Wind can carry the haploid spores some distance. The haploid generation is the dominant generation.
How are windblown spores an adaptation to reproduction on land?
Windblown spores, which lack flagella, no longer require water for dispersal
Two types of vascular tissue
Xylem - Conducts water and dissolved minerals upward from the roots Phloem - Conducts sucrose and hormones throughout the plant
Are ferns better adapted to a land environment than mosses? Why or why not?
Yes. Ferns have vascular tissue in the dominant sporophyte.
Plants are:
a diverse group of multicellular organisms.
Brownish clump found underside the leaves is called
a sorus
Life cycle
alternation of generation
Spores are released when the thick cells of an ___________ dry out and the sporangium opens.
annulus
In the plant life cycle, the generation that produces gametes is (n or 2n)
haploid (n)
Fronds
large leaves also called megaphylls
In the seedless vascular plants the ___________ is dominant.
sporophyte
