BIO 219 Plant Physiology Study Questions CH28-29
Based solely on numbers of species, the most successful seedless plants today are:
ferns
Which of the following is/are true with respect to seedless vascular plants?
ferns are the most numerous species in this group
What major reproductive adaptations facilitated the evolution of the seed?
-the reduced gametophytes - sexually different spores -protection of female spores and gametophytes within the body of the sporophyte -evolution of ovule (developmental precursor of the seed)
In addition to having simple vascular tissue, seedless vascular plants differ from all bryophytes in that:
the sporophyte generation is dominant
What are some important ecological and economic roles of seedless plants?
-When bryophytes colonize bare land, their bodies trap organic and inorganic matter, helping to build soil on bare rock and stabilizing soil surfaces They also are crucial components for the food web. -Hornworts increase the amount of nitrogen available for plants.
How did seeds, pollen, and pollination affect the diversification of seed plants?
The evolution of pollen and pollination permitted sexual reproduction in the absence of environmental water, allowing seed lineages to radiate and diversify into wide range of new, drier habitats. The survival advantages of seeds-including protection and nourishment of embryos- facilitated this diversification.
In comparing bryophytes and seedless vascular plants, which of the following statements is not accurate?
both groups have lignified cells in some body parts
Which feature(s) do ferns share with all other land plants?
sporophyte and gametophyte life cycle stages
A homeowner noticed moss growing between bricks on his patio. Closer examination revealed tiny brown stalks with cuplike tops, emerging from green leaflets. These brown structures were:
the sporophyte generation
Which of the following is not an evolutionary trend among plants?
becoming seedless
Give some examples of bryophyte features that bridge aquatic and terrestrial environments.
-Bryophytes produce flagellated sperm that must swim through water to reach eggs and they lack a complex vascular system. (reproduce sexually and asexually) -They have rhizoids (root-like) and have stem and leaf like structures as well. -Sporophytes have some water-conserving cuticle and stomata.
What are distinguishing features of cycads, ginkgos, and gnetophytes?
-Cycads superficially resemble small palms and are remnants of a lineage that's likely arose from a seed fern ancestor. -Gingko closely resemble fossils going back at least 200 millions years - Gnetophytes are structurally and functionally simpler than most other seed plants
Describe the difference between homospory and heterospory, and explain how heterospory paved the way for other reproductive adaptations in land plants.
-Homospory: plant produces a single type of sexual spore (bisexual) with each gametophyte capable of producing both sperm and eggs. -Heterospory: (gymnosperms and angiosperms) produce 2 spores that are sexually different gametophytes (sperm or egg). -Heterospory developed protection of male gametes in pollen grains and protection of plant embryos inside seeds.
Compare and contrast the lycophyte and bryophyte life cycles with respect to the sizes and longevity of gametophyte and sporophyte phases.
-In bryophytes, the gametophyte is much larger than the sporophyte and obtains it's nutrition independently. The tiny sporophyte remains attached to the gametophyte and depends on it for nutrition. -In lycophytes, the gametophyte is free living and smaller than the sporophyte which is a photosynthetic autotrouph.
How does the life cycle of a horsetail differ from that of a fern?
-In horsetails, the sporangia that produce spores are born in strobili where spores are carried away from the plant by air currents. -In ferns, sporangia are produced on the lower surface/margin of leaves where spores are forcefully dispersed from the parent plant when the contraction of a belt-like annulus rips open and the sporangium ejects the spores.
Give some examples of ways seedless plants have been used as model research organisms.
-Sequenced genomes of lycophytes and moss are proving extremely useful in elucidating the evolutionary pathways of groups throughout the plant kingdom.
How did plant adaptations such as a root system, a shoot system, and a vascular system collectively influence the transition to terrestrial life?
-The root system gave land plants access to minerals and water in soil and provided physical support for aerial parts. - The shoot system of land plants allowed vascular plants to grow taller and stay erect, gaining better access to sunlight for photosynthesis. -Vascular tissue were innovations for distributing water(xylem) and sugars(phloem) throughout the plant.
Which is the correct matching of phylum and plant group?
Hepatophyta: liverworts
How do specific aspects of a moss plant's anatomy resemble those of vascular plants?
Mosses are bryophytes that mostly resemble vascular plants. They have some species with a water-conducting tissue that resembles the xylem and some species with a sugar-conducting tissue resembling the phloem.
In ferns, whisk ferns, and horsetails, what kind of structures fulfill the roles of roots and leaves?
Rhizomes (underground stem) are the root-like structures in ferns. Whisk ferns lack true leaves and roots so they have leaf-like scales (branching stem) from the rhizome anchored by the rhizoids. Horsetails have underground rhizomes and roots anchored to the soil.
Why are gymnosperms called "naked seed" plants?
They are not enclosed within floral structures but instead develop on the shelf-like scales of ovulate (females) cones.
Which of the following were adaptations that occurred as plants made the evolutionary transition to a terrestrial existence?
mechanisms for gaining access to nutrients in soil
Which of the following is not generally thought to be accurate with respect to the evolution of leaves?
nly macrophyll-type leaves, which have stomata and a network of veins, are observed in extant plant species
