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Unformatted text preview: the female gametophyte that gives rise to the endosperm are the two polar nuclei that combine with sperm and form a triploid (3n) nucleus in the center of the large central cell of the female gametophyte. This large cell gives rise to endosperm. 2 polar nuclei that combine with sperm & form triploid nucleus in large central cell of female gametophyte give rise to endosperm 16. The function of fruit is to protect the enclosed seeds and, when mature, aids in their dispersal by wind or animals. fruit protects seeds and aids in dispersal 17. The mechanisms utilized by plants to discourage self-fertilization are dioeious (separate male and female), stamen and sepals that mature at different times or are structurally arranged to prevent pollen transfer by a pollinator from another to stigma in the same flower, or self-incompatibility; (rejects own pollen-- most common). example of what is not a mechanism = brightly colored bracts that replace petals 18. Asexual vs sexual reproduction Advantages: -no need for pollinator -plant can pass on all its genetic legacy intact -clones not as fragile as seedlings produced by sexual reproduction Disadvantages: -variation in offspring that enables reproductive success in an unstable environment -seeds, which are almost always produced sexually, facilitate dispersal Chapter 39: Plant Responses to Internal and External Signals 1. E tiolation - plant morphological adaptions for growing in darkness H ormone - (plant hormones)- control plant growth and development by affecting division, elongation, and differentiation of cells P lant growth factor - (same as hormone) T ropism - a growth response that results in the curvature of whole plant organs toward or away from a stimuli due to differential rates of cell elongation 2. The three stages of signal transduction are reception, transduction, and response. three stages of signal transduction are reception, transduction, and response 3. Second messengers are small molecu...
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This document was uploaded on 03/02/2014 for the course BIO 109 at University of Missouri-Kansas City .

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