VISUAL SUMMARY
REPRODUCTION IN SEED PLANTS
FIGURE 22–15 The two major groups of seed plants can be distinguished by their reproductive structures. Interpret Visuals How is the location of developing seeds different in the two groups?
dPollen In seed plants, the entire male gametophyte is contained in a tiny structure called a pollen grain. Sperm produced by this gametophyte do not swim through water to fertilize the eggs. Instead, pollen grains are carried to the female reproductive structure by wind or animals such as insects. The transfer of pollen from the male reproductive structure to the female reproductive structure is called pollination.
Seeds After fertilization, the zygote contained within a seed grows into a tiny plant—the sporophyte embryo. The embryo often stops growing while it is still small and contained within the seed. The embryo can remain in this condition for weeks, months, or even years. A tough seed coat surrounds and protects the embryo and keeps the contents of the seed from drying out. Seeds can survive long periods of bitter cold, extreme heat, or drought. The embryo begins to grow when conditions are once again right; it does this by using nutrients from the stored food supply until it can carry out photosynthesis on its own.
In Your Notebook Make a Venn diagram that records the shared and distinct characteristics of gymnosperms and angiosperms.
MYSTERY CLUE
Samples of material taken from Iceman's digestive tract contained pollen from plant species that grow at different elevations. How could this evidence be used to reconstruct Iceman's movements on his last day alive?
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