BIOL 2242 Lecture Notes - Lecture 5: Epicotyl, Hypocotyl, Cotyledon

• School: University of Manitoba
• Department: Biological Sciences
• Course: BIOL 2242
• Professor: Isobel Waters

Document Summary

If so, what is it: does hypocotyl elongate, what is the fate of the cotyledon(s), do they end up above of below ground? (if above ground, more subject to herbivory) Epigeous (epi above, geo earth) e. g. bean: cotyledon(s) raised aboveground. In beans, by hypocotyl hook: protects epicotyl. Hook straightens: stem elongates, foliage leaves develop, variant in onion. Hypogeous (hypo above, geo earth) e. g. corn: cotyledon(s) stay belowground. Variant in pea: epicotyl emerges in hook formation (very slight) Forms (614: annuals: complete life cycle in 1 year. Most are semelparous, with flowering initiating death. Epigeous germination in bean (phaseolus vulgaris)and onion (allium cepa). Hypogeous germination in pea (pisum sativum) and corn (zea mays). secondary growth: biennials: complete cycle in 2 years; e. g. carrot, evening primrose. Herbaceous: have non-woody shoots (cid:498)die back(cid:499) yearly. Can live as long or longer than woody perennials: have persistent roots with secondary tissues. Woody: persistent woody tissues in roots and shoots.