Figure 3-22. Alternation of generations of corn.

Figure 3-22

Alternation of generations of corn. The male gametophyte arises from a meiocyte in the tassel. The female gametophyte arises from a meiocyte in the ear shoot. One sperm cell from the male gametophyte fuses with an egg nucleus of the female gametophyte, and the diploid zygote thus formed develops into the embryo. The other sperm cell fuses with the two polar nuclei in the center of the female gametophyte, forming a triploid (3n) cell that generates the endosperm tissue surrounding the embryo. The endosperm provides nutrition to the embryo during seed germination. Which parts of the diagram represent the haploid stage? Which parts represent the diploid stage?

From: Mendelian genetics in eukaryotic life cycles

Cover of An Introduction to Genetic Analysis
An Introduction to Genetic Analysis. 7th edition.
Griffiths AJF, Miller JH, Suzuki DT, et al.
New York: W. H. Freeman; 2000.
Copyright © 2000, W. H. Freeman and Company.

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