Bio 201 S12 Lect 9(True v3r

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Unformatted text preview: hermaphrodi;c (describes a condi;on in some angiosperms) –  male and female parts found in the same flower Fer;liza;on of the egg may not occur unit aJer the ovules have been shed The decaying ;ssue around the seed smells strongly rancid S;ll the seed is a delicacy and is used in herbal medicine Trees are quite resistant to smog, and are planted in many ci;es ginkgo in medicine •  gingko extracts contain flavonoid compounds –  plants uses as ‘secondary compounds’ to resist herbivory •  thought to enhance memory •  currently under clinical inves;ga;on as possible treatment for demen;a –  e.g. Alzheimer’s disease hHp:// istockphoto_3848553‐ginkgo‐biloba‐and‐pills‐planner.jpg hHp:// Angiosperm “Angiosperm”: derived from two Greek words “Angeion” = container, jar “Sperma” = seed Gymnosperm = “naked seed” evolu;onary innova;ons of angiosperms •  Double fer;liza;on •  triploid nutri;ve ;ssue: endosperm •  produced during double fer;liza;on •  Ovules and seeds enclosed in a carpel •  Flowers •  Fruits •  Xylem with vessel elements and fibers •  Phloem with companion cells Double Fer,liza,on 6 haploid cells in megagametophyte plus 2 polar bodies at one end: egg plus 2 synergids egg gets fer;lized by 1 of the 2 sperm nuclei synergids help aHract sperm to egg at other end: three an,podal cells eventually degenerate other sperm nucleus fuses with the two polar nuclei to form the triploid endosperm hHp:// endosperm •  part of the seed of angiosperms •  contains oils, proteins, and most importantly for the embryo: starch –  embryo’s nutri;on supply •  makes many types of seeds valuable as human food –  grain flour (wheat, barley, oat, etc.) is endosperm –  meat of coconuts –  white part of popcorn transfer cells – help transfer sugars from plant to seed/fruit aleurone – present in seeds of grasses (cereals); contains protein; can contain pigments (e.g. anthocyanin in Indian corn Pollina,on and Fer,liza,on Double Fer,liza,on Sperm Male gametophyte Egg Carpel Female gametophyte Ovule Flowers are compressed, reproduc,ve shoots Anther=Sporangium Pollen=Spore Sperm=male gamete Carpel Ovule~Sporangium Embryo-sac=Female gametophyte Egg=female gamete...
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This note was uploaded on 10/02/2013 for the course BIO 201 taught by Professor True during the Spring '08 term at SUNY Stony Brook.

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