FIGURE 22–23 Comparing Plants by Life Span Categories of plant life spans include annuals, biennials, and perennials. Interpret Tables Which flowering plant completes its life cycle in one year?
dAnnuals, Biennials, and Perennials If you've ever planted a garden, you know that many flowering plants grow, flower, and die in a single year. Other types of plants continue to grow from year to year. The life span of plants is determined by a combination of genetic and environmental factors. Many long-lived plants continue growing despite yearly environmental fluctuations. However, harsh environmental conditions can shorten the life span of other plants. The characteristics of the three categories of plant life spans—annual, biennial, and perennial—are summarized in Figure 22–23.
22.4 Assessment
-
Review What reproductive structures are unique to angiosperms? Briefly describe the function of each.
Form a Hypothesis Which are more likely to be dispersed by animals—the seeds of an angiosperm or seeds of a gymnosperm? Explain your reasoning.
-
Review What are three common ways to categorize angiosperms?
Explain How do these methods of categorization differ from scientific classification methods?
Form an Opinion Is it useful or misleading to categorize angiosperms in ways that do not reflect evolutionary relationships? Defend your opinion.
VISUAL THINKING
Prepare a display comparing two specific plants—one monocot and one dicot. On this display, show photographs or drawings of the plants and write a brief summary of the basic differences between these two types of angiosperms.
Table of Contents
- Formulas and Equations
- Applying Formulas and Equations
- Mean, Median, and Mode
- Estimation
- Using Measurements in Calculations
- Effects of Measurement Errors
- Accuracy
- Precision
- Comparing Accuracy and Precision
- Significant Figures
- Calculating With Significant Figures
- Scientific Notation
- Calculating With Scientific Notation
- Dimensional Analysis
- Applying Dimensional Analysis