Use the information in the chart you have completed to answer the questions.
1.Some of the major plant groups are listed in the following table from most primitive to most advanced. For each group, indicate what major characteristics make it more advanced than the preceding group. For example, how are ferns more advanced than mosses?
Plant group
CharophyceansBryophytesLycophytesPterophytesGymnospermsAngiospermsAdvance(s) over preceding groupPeroxisomes help reduce photores-piration, and chlorophyll b is less susceptible to UV bleaching.Jacketed gametangia (archegonia and antheridia). cuticle, and air spaces help protect from desiccation.Dominance of sporophyte generation helps reduce the effect of UV mutation of DNA. Vascular tissue, xylem, and phloem increase support against gravity and provide greater efficiency of water and food transport.Rhizomes increase the ability to pick up water from the soil. True leaves (with vascular tissue) increase photosynthe tic surface areas and therefore food production.Pollen grain removes the need for water for transport of male gametes. Seed allows the next-genaration sporophyte offspring to begin development on a sporophyte parent plant. Seed prevents desiccation and allows embryo to survive until conditions are appropriate for germination. Seed also includes food source for early growth.Flower attracts animal pollinators and increases the probability of outcrossing and fertilization. Fruit increases dispersal probability. Offspring (seeds) are transported to new location (away from the parent plant) by animals.
2.How do the bryophytes differ from the seedless vascular plants? How are they similar?Refer to the previous table. Differences between bryophytes and the seedless vascular plants are:
a.the dominant phase of the life cycle.In bryophytes the gametophyte stage is dominant; in seedless vascular plants the sporophyte is dominant.
b.the absence/presence of vascular tissue.
Ch 27_40-18Reece_IG
Bryophytes contain no vascular tissue. As a result, they do not have true stems, roots, or leaves.
c.the absence of guard cells in bryophytes.Both bryophytes and seedless vascular plants have air spaces in their structure for gas exchange. However, the bryophytes do not have guard cells associated with their air spaces. Guard cells allow plants to control the size of the stomata.In most other major features (listed in the table), these two groups are similar.
3.The life cycle of all land plants includes an alternation of generations between a multicellular gametophyte phase and a multicellular sporophyte phase.Diagram the life cycle of a seed plant.Refer to Figures 30.6 and 30.10 in Campbell Biology, 9th edition. See also Figure 13.6 on page 252.
a.What cellular division process always precedes formation of the gametophyte generation?Meiosis
b.What cellular process always precedes formation of the sporophyte generation?
