Biology: The Dynamic Science

Peter J. Russell, Paul E. Hertz, Beverly McMillan

Chapter 28

Seedless Plants - all with Video Answers

Educators

Chapter Questions

Problem 1

Which of the following is not an evolutionary trend among plants?
a. developing vascular tissues
b. becoming seedless
c. having a dominant diploid generation
d. producing nonmotile gametes
e. producing two types of spores

Joanna Quigley

Joanna Quigley

Numerade Educator

Problem 2

Which of the following were adaptations that occurred as plants made the evolutionary transition to a terrestrial existence?
a. increased motility of gametes on dry land
b. a flattened plant body that increased exposure to the Sun
c. a reduction in the number and distribution of roots
d. mechanisms for gaining access to nutrients in soil
modifications that allowed stems and leaves to absorb water from the atmosphere

Danielle Ashley

Danielle Ashley

Numerade Educator

Problem 3

Which of the following is not generally thought to be accurate with respect to the evolution of leaves?
a. Leaves arose more than once during land-plant evolution.
b. Microphylls may have arisen as modifications of the main vertical stem.
c. Megaphylls may have come about as modifications of stem branches.
d. The evolution of higher-density leaf venation correlates with increased capacity for photosynthesis.
e. Only macrophyll-type leaves, which have stomata and a network of veins, are observed in extant plant species.

Danielle Ashley

Danielle Ashley

Numerade Educator

Problem 4

Which is the correct matching of phylum and plant group?
a. Hepatophyta: liverworts
b. Anthocerophyta: mosses
c. Bryophyta: horsetails
d. Lycophyta: ferns
e. Monilophyta: hornworts

Danielle Ashley

Danielle Ashley

Numerade Educator

Problem 5

Which feature(s) do ferns share with all other land plants?
a. sporophyte and gametophyte life cycle stages
b. gametophytes supported by a thallus
c. dispersal of spores from a sorus
d. asexual reproduction by way of gemmae
e. water uptake by means of rhizoids.

Joanna Quigley

Numerade Educator

Problem 6

In addition to having simple vascular tissue, seedless vascular plants differ from all bryophytes in that:
a. they do not require free water for fertilization.
b. the sporophyte generation is dominant.
c. most do not require a moist, humid, or shaded habitat.
d. the group is much more diverse, with many more species overall.
e. most have a feathery or flattened thallus.

Joanna Quigley

Numerade Educator

Problem 7

In comparing bryophytes and seedless vascular plants, which of the following statements is not accurate?
a. In general, bryophyte traits more closely resemble those of algae.
b. The leaves, stems, and roots of seedless vascular plants are not homologous with similar bryophyte structures.
c. Both groups have lignified cells in some body parts.
d. Bryophytes lack complex conducting tissues (xylem and phloem).
e. Seedless vascular plants have sexual and asexual reproductive modes, but in bryophytes only asexual reproduction has been observed.

Danielle Ashley

Danielle Ashley

Numerade Educator

Problem 8

Based solely on numbers of species, the most successful seedless plants today are:
a. horsetails.
b. ferns.
c. liverworts.
d. mosses.
e. club mosses.

Joanna Quigley

Numerade Educator

Problem 9

Which of the following is/are true with respect to seedless vascular plants?
a. Ferns are the most numerous species in this group.
b. Lycophyte species grow the largest of all modern seedless vascular plants.
c. Seedless vascular plants, including trees, shrubs, and herbaceous ("nonwoody") species dominated Earth's terrestrial environments for nearly 200 million years.
d. The strobilus, where spore-producing parts sporangia are located, is a reproductive adaptation found in all seedless vascular plants.
e. In the fern life cycle, the young sporophyte is dependent on the gametophyte, but quickly develops into an independent, larger plant with its own root system and leaves where photosynthesis occurs.

Joanna Quigley

Numerade Educator

Problem 10

A homeowner noticed moss growing between bricks on his patio. Closer examination revealed tiny brown stalles with cuplike tops emerging from green leaflets. These brown structures were:
a. the sporophyte generation.
b. the gametophyte generation.
c. elongated haploid reproductive cells.
d. archegonia.
e. antheridia.

Danielle Ashley

Danielle Ashley

Numerade Educator

Problem 11

Working in the field, you discover a fossil of a previously undescribed plant species. The specimen is small and may not be complete; the bits you have do not include any floral parts. What sorts of observations would you need in order to classify the fossil as a seedless vascular plant with reasonable accuracy? What evidence would you need in order to distinguish between a fossil lycophyte and a fern?

Danielle Ashley

Danielle Ashley

Numerade Educator

Problem 12

As described in Section 28.2 one proposed bryophyte phylogeny considers hornworts and vascular plants (such as lycophytes and ferns) to be sister clades. Among other factors, a shared morphological feature supports this hypothesis: hornwort and vascular plant sporophytes both show indeterminate growth-once a sporophyte develops, it grows for the remainder of the plant's life. Indeterminate growth has not been observed in other bryophyte lineages. Can you think of a different evolutionary explanation for the growth pattern shared by hornworts and vascular plants?

Josee Pacheco

Numerade Educator

Problem 13

Compare the size, anatomical complexity, and degree of independence of a moss gametophyte and a fern gametophyte. Which one is the most protected from the external environment? Which trends in plant evolution does your work on this question bring to mind?

Josee Pacheco

Numerade Educator

Problem 14

Design an Experiment A moss species that you study occurs in lush abundance in the moist, shaded forest floor in a grove of coast redwoods (Sequoia sempervirens) in Northern California. When one of the massive old trees abruptly topples over, there is a dramatic increase in the amount of light and air movement in a sizable patch of the moss" habitat. This is a rare opportunity for you to study the effects on the moss of a sudden shift in the environmental conditions in which it grows. Devise an experimental plan to guide your research, including hypotheses about one or more ways the change may affect the species" growth and/or life cycle.

Josee Pacheco

Numerade Educator