Development of Female Gametophytes While the male gametophytes are forming, female gametophytes develop inside each carpel of a flower. The ovules—the future seeds—are enveloped in a protective ovary—the future fruit.
How do the female gametophytes form? As shown in the bottom half of Figure 24–3, a single diploid cell goes through meiosis to produce four haploid cells, three of which disintegrate. The remaining cell undergoes mitosis, producing eight nuclei. These eight nuclei and the surrounding membrane are called the embryo sac. The embryo sac, contained within the ovule, makes up the female gametophyte of a flowering plant.
Next, cell walls form around six of the eight nuclei. One of the eight nuclei, near the base of the gametophyte, is the nucleus of the egg—the female gamete. If fertilization takes place, this egg cell will fuse with the male gamete to become the zygote that grows into a new sporophyte plant.
ZOOMING IN
THE DEVELOPMENT OF GAMETOPHYTES
FIGURE 24–3 The diagrams show the development of the male gametophyte inside an anther and the development of the female gametophyte inside a single ovule. Interpret Visuals In each case—male and female—which cellular process produces the first haploid cell?
d
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