BIOL10004 Lecture Notes - Lecture 11: Double Fertilization, Pollen Tube, Plant Reproduction
BIOL – Lecture 11
Plant reproduction
Reproduction in different plants
• Process includes parts of cell & molecular biology, growth/development, ecology
• Reproductive organs in angiosperms are aggregated into flowers
o Angiosperms have double fertilisation
• Pollination is achieved by a diverse array of mechanisms
• Breeding systems determine the pattern of mating within a population
• Fruits are variously adapted for seed protection and dispersal
• Vegetative (non-sexual) reproduction can be important, but no genetic variation
• Important knowledge for biodiversity conservation and plant breeding
Reproduction – flowers
• Stamens (male) consist of anther (contains pollen) & filaments
• Carpels (female) consist of ovary, ovules, style and stigma
• Pollen lands on stigma surface (receptor) ; pollen tube grows to ovule
• Angiosperms – seed i a essel – refers to the carpel
• Sepals - protection
life cycle of angiosperms
• Angiosperm gametophytes are extremely reduced
o Female gametophyte is inside ovule (8 cells)
o Male gametophyte develops from pollen grain (3 cells)
• Double fertilisation:
o 2 sperm nuclei from germinated pollen grain fertilise ovule
o one fuses with egg cell to form zygote and new embryo
o other fuses with 2 polar nuclei to form endosperm (food reserve for embryo)
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