Plant Reproduction, Exams of Anatomy

Download Plant Reproduction and more Exams Anatomy in PDF only on Docsity! Plant Reproduction Asexual Reproduction • Asexual reproduction is natural “cloning.” Parts of the plant, such as leaves or stems, produce roots and become an independent plant. Terms to know: • Spore: haploid reproductive cell that leads to a gametophyte in plant alternation of generations. • Gamete: mature haploid male or female germ cell able to unite with another of the opposite sex in sexual reproduction to form a zygote. • Zygote: diploid, eukaryotic cell formed during fertilization event between two gametes, combining DNA of each gamete, containing the genetic information to form a new individual. Terms to know: • Sporophyte: diploid, multicellular stage which develops from zygote, produced when a haploid female cell is fertilized by a haploid male cell, produces haploid spores by meiosis. • Gametophyte: haploid, multicellular stage, develops from a spore by mitosis, produces haploid gametes by mitosis. Plant Life Cycle Non-flowering plants • Mosses, ferns, and related plants have motile, swimming sperm. Moss Life Cycle General nae eens s Youn Life Cycle =m smosngun of a Moss Sporgenous tissue * *Peristome . OBOE pHYTE . Hy : G Nn “aie FERT Sperm,” Vane A Je f = of" Spores Ego @ : Ai@iegoniuiat F ricer P Bud Rhizoid— Female Gametophyte 5 g Fern Life Cycle mature sporophyte (2n) = * Ls _~ clusters of —— = 4 A we spores (n) my, > ” @ , wa S$ * S spore - case young we be gametophyte (n) ~ young sporophyte (2n) mature—— ‘{ gametophyte J mature gametophyte fusion to #) form zygote haploid diploid Conifer pollination • Conifers are wind-pollinated plants. • Chance allows pollen to land on scales of female cones. • Pollen germinates, grows a pollen tube into egg, allows sperm to fertilize egg. Flowers Pollen go-betweens • Showy flowers are the result of selection for more efficient pollination strategies. • Flower parts are modified leaves. Those that were brightly colored attracted insects in search of pollen. Imperfect flowers Angiosperm Life Cycle Gametogenesis: Male microspore mother cell (2n) nucleus nucleus of tube cell microspores Aa (n) <q sperm immature > esha nals cells pollen grain (n) ak call gametophyte (n) ! rat ele (pollen grain) ube cel cytoplasm of tube cell haploid ee Flower to Fruit ripening ovary __ “flesh” of -gs wall pepper ovary —> pepper fruit ovule —> seed pepper flower pepper fruits Ovule to Seed * integuments ——»> seed coat ————-4 | (diploid) r central ———_> endosperm —~——__ cell (triploid) / “ 6 zygote ————> embryo ——==—_——_=_ (diploid) , = fertilized ovule seed (a) Early development of the seed seed Anatomy embryonic root embryonic leaves shoot hypocotyl seed coat cotyledons (c) Bean seed (dicot)