BIOL10003 Lecture Notes - Lecture 11: Fundamental Frequency, Outcrossing, Sporophyte
Plant Reproduction
Reproductive system(organ) of angiosperms ( flowers)
Plant Reproduction
• Plat epodutio is ultidisiplia: ell ad oleula iolog, goth ad
development, genetics, and ecology
• ‘epodutie ogas i agiospes ae aggegated ito floes
• Agiospes hae doule fetilizatio
• Polliatio is ahieed a diese aa of ehaiss
• Beedig sstes deteie the patte of atig ithi a populatio
• Fuits ae aiously adapted for seed protection and dispersal
• Vegetatie o-sexual) reproduction is important in some instances
• Ipotat koledge fo iodiesit oseatio ad plat eedig
Asexual
• vegetative reproduction
• Do ot hae to el o the climate and seasons
• potatoes
• No sex. No seed. Results in clones
• Tues
• “ukes
• ‘ues
• Buddig
• Fagetatio/“heddig
• Sepals- main function is protection, enclose the bud and protect it
• Petal – display, attract the attention of pollinator
• Stamens (male) consist of a filament ( holds it in position) and anther ( where pollen is
produced and shed)
• Capels feale osist of oa(holds numerous
ovules), ovules ( contain egg cells), style ( sterile tissue
that links the stigma to the ovule)and stigma (sticky
surface( due to a pulpous structure and glutose
coating) where pollen is received and accepted)
• Pollen lands on stigma surface; pollen tube grows to
the ovule
• Angiosperms - seed i a essel efes to the
carpel)
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Angiosperm Life cycle
megaspores sex cells
Independent diploid sporophyte
- flower meiosis produce sex cells called megaspores and when megaspores goes through
mitosis to produce haploid gametophyte (male and female).
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Fertilization between diminutive gametophytes
Female gametophyte is inside the ovule (8 cells)
important- polar nuclei (2 haploid cells), egg
after pollination the pollen tube (male gametophyte) and is composed of 2 cells the
generative and the tube nucleus. The pollen tube is driven down by the tube nucleus and
then the generative nucleus. Just before fertilisation the generative nucleus divides into two
cells, 2 haploid sperm nuclei. (male gametophyte is now composed of 3 cells), This is a
double fertilisation. The first sperm nucleus comes through the pollen tube that invade the
ovule through the synergids cells (guard cells) and fertilization happens. Once this happens,
the second sex cell comes and unite with the 2 polar nuclei and form a triploid tissue which
goes on to divide and form the endosperm (maternal provisioning of the embryo (carbs
etc)). Double fertilization means you only provide the embryos that have been fertilized.
Male gametophyte develops from the pollen grain (3 cells)
Coconut
- 2 phases – liquid and solid, power the embryo
- carpel swells are forms the husk ( for dispersal and protection)
carpel can also harden to protect the seeds.
- carpel walls develop into fruits
- ovule becomes the seed.
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