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Introduction to Plant Reproduction 23.1 23.2 MASHAEL ALHAIDAR - Coggle…
Introduction to Plant Reproduction
23.1 23.2
MASHAEL ALHAIDAR
Vegetative Reproduction
vegetative reproduction if a form of asexual reproduction where the new plant grows from parts of the old plant
Advantages
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Faster than sexual reproduction , and only one parent plant is needed for vegetative reproduction
produces uniform offspring
An agricultural technique to produce fruit
Naturally occurring vegetative reproduction
Fragments of plants such as mosses can be scattered by the wind , and resume growth in a new location
Some plants produce horizontal roots that can grow new plants , even after the root is cut.
Directed vegetative reproduction farmers and scientist can use buds, leaves, stems , or root pieces from certain plants to grow new plants. ( potatoes can be cut into sections , each section contains bud can grow into new plant.
Alternation of Generations
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moss reproduction and life cycle characteristic of most non vascular plants
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Gametophyte stage is dominant ( larger )
Eggs are produced in the archegonium , female structure
Sperms produced in antheridium , male structure
Flagellated sperm require water to reach archegonium
Sperms move towards archegonium response to chemical released by the female gametophyte , its called chemotaxis
sporophyte, which releases spores, and gametophyte, which releases gametes. Gametophyte plants are haploid, sporophyte plants diploid.
Fern Reproduction and Life Cycle
The fern life cycle is divided into two parts. On the underside of the leaves, mature plants generate spores. When these seeds germinate, they develop into prothalli, which are little heart-shaped plants.
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Conifers are heterosporous, generating two different types of spores: male microspores and female megaspores.
1-Pollination
pollination occurs when transferring pollen grains from the male anther of a flower to the female stigma
2-Seed development
1-pollen grain grows a pollen tube into the ovule
2-after fertilization zygote is dependent on female gametophyte white undergoes cell division and becomes embryo
3-as embryo developing a outside layer forms a seed coat
the nuclei inside the mega spore is called polar nuclei
The fronds contain spore-producing structure called sori
flower organs
Sepals: to protect the flower
Petal: are colorful and attract pollinators gives them a place to land.
`Stamen : male reproductive structure
Pistil : female reproductive structure
complete flower
the flower contain the major 4 parts
incomplete flowers the flower missing 1 part of more
perfect flowers
flowers that have both stamens and pistils
imperfect flowers flowers that have only stamens or pistils.
structural differences
Monocots , multiples of 3 ( yellow)
flower adaptations
pollination mechanisms
flower adaptation that relate to pollination includes flower , size , shape , color , and petal arrangements.
self pollination
when the pollen from the anther is deposited on the stigma of the same flower, or another flower on the same plant
cross pollination
flowers only pollinators for reproduction
Animal pollination :flowers are brightly colored or strongly scented to attract pollinators
Wind pollination : flowers lack showy or fragrant flowers , produces large amount of lightweight pollen
Eudicots multiple of 4,5 ( purple)
photoperiodism
The response to changes in daylength that enables plants to adapt to seasonal changes in their environment
critical period
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flowering plants are divided into 4 groups based on critical period.
2- long day photoperiodism
They require the periodic exposure of light exceeding the critical period to induce flowering
3- intermediate day photoperiodism
number of hours of darkness is neither too great or too few
1- short day photoperiodism
They require the periodic exposure of light less than the critical period to induce flowering
4- day neutral photoperiodism
plants does not depend on the photoperiod.
specific range of drakness hours that initiate flower development
