plant reproduction
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Plant Reproduction. Unit 6 – Lecture 6. Alternation of Generations. type of reproduction utilizing asexual & sexual means. Alternation of Generations. offspring generations alternate between being haploid [1n] in one generation to being diploid [2n] the next. Alternation of Generations. - PowerPoint PPT PresentationTRANSCRIPT
Unit 6 – Lecture 6
Alternation of Generationstype of reproduction
utilizing asexual & sexual means
Alternation of Generationsoffspring generations
alternate between being haploid [1n] in one generation to being diploid [2n] the next.
Alternation of Generationsin some plants, the
sporophyte is a completely different plant than the gametophyte.
in others, the gametophyteis something we really don’t see.
Alternation of GenerationsSporophyte [2n]
produces spores [1n]through meiosissporophyte is the
typical “adult plant” that we see
Alternation of GenerationsSpores [1n] produce
gametophytes [1n] throughmitosis
Alternation of GenerationsGametophyte [1n]
produces gametes [1n]through mitosis
Alternation of GenerationsGametes [1n] fuse
in fertilization to produce zygote [2n]
Alternation of GenerationsZygote [2n] grows to
become embryo [2n]
Alternation of GenerationsEmbryo [2n] grows
to become sporophyte [2n]…
etc.
Alternation of Generationsnon-vascular and non-seed plants MUST have
water to reproduce.flagellated sperm must swim to egggametophyte can be very
small, but visible – 1cm or less.
Other Asexual Reprod Methodsvegetative reproduction – new plant forms
from existing plant part (roots)
fragmentation – new plant forms from a cutting of the original plant.
Seed Plantsare vascular…two varieties:
gymnosperm – produce conesangiosperm – produce flowers
Angiospermsproduce flowers and seeds inside of a fruit
petals, pistil, stamen, etc.petals attract pollinatorsfruit attracts organisms which can spread
seeds
Angiosperms
Angiosperms
Angiospermsare either monocot or dicot
cotyledon – the seed “leaves” or sides / food supplies
don’t need to know these directly:have different types of xylem & phloemhave different types of veinationhave differences in petal arrangement
Seed Production
Germinationgermination – zygote growing into new plant
requirements: watersuitable temperatureoxygentime
Germinationgermination – zygote growing into new plant
requirements: light other:
freezing – applessoaking in salt
water – coconutsfire – many
coniferscannot be halted