Botanica - Tema 3

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  • Created by: Laraa94
  • Created on: 04-05-16 15:25

Asexual Reproduction

Reproduction can be asexual or sexual
Sexual - meiosis and singamia (fertiliastion)
Asexual - mitosis, no cells nor sexual nuclei. Offspring have same genetic info as parents, apart from mutations. Effective for geographic spread in media adapted for the species. Types unicellular:

  • Binary fission - cell divides by mitosis and parent becomes two daughter cells 
  • Germination - cellular division in yeast. Small bud (yema) where mitosis of nucleus occurs, leaving one daughter nucleus in the orignial cell and the other in the bud - eventually strangled, grows and becomes a new veg cell.
  • Pluripartición - mother cell divides nucleus several times - mitosis and several daughter cells

Pluricellular:

  • Propagules - give rise to new plants (talo, brio and cormo)
  • Spores - unicellular structures, varied morph. only talofitos. Endo - inside esporangio. Exo
  • Fragmentation - eg. strawberries 
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Sexual Reproduction

Two basic phases - fertilisation and meiosis, can happen immediately or separately. Monoecious plants have male+female reprod. organs (hermaphrodites). Types of fertilisation: 

  • Form gametes - Isogamia - gametes identical, flagellated. Anisogamia - morph. different gametes fuse, small = masc, big = female (substances for zygote). Oogamia - extreme anisogamia
  • Do not form gametes
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