/67Ch41PlantReproduction200722

Plant Reproduction

I n a nutshel l

AP Biology

2007-2008

Plant Diversity fern

mosse s

s

conifer s

flowering plants

Bryophytes

Pteridophytes

Gymnosperm

Angiosperm

non-vascular land plants

seedless vascular plants

pollen & “naked� seeds

flowers & fruit

flowers & fruits

pollen & seeds

vascular system AP Biology

common

xylem cells tracheids

Animal vs. Plant life cycle Animal

Plant

diploid multicellular individual 2n mitosis

meiosis

fertilization haploid unicellular gametes 1n AP Biology

diploid multicellular sporophyte 2n mitosis fertilization

meiosis

gametes 1n

spores 1n

mitosis

mitosis haploid multicellular gametophyte 1n

alternation of

Bryophytes  Mosses & liverworts non-vascular diploid  swimming sperm multicellular  dominant haploid gametophyte sporophyte  dependent sporophyte 2n mitosis  spores for reproduction meiosis fertilization 

gametes 1n

spores 1n

mitosis

mitosis haploid multicellular gametophyte 1n

AP Biology alternation of

Pteridophytes  Ferns vascular  swimming sperm  dominant sporophyte  independent gametophyte 

 fragile 

spores for reproduction

haploid archegonia

antheridia AP Biology alternation of

diploid multicellular sporophyte 2n mitosis fertilization

meiosis

gametes 1n

spores 1n

mitosis

mitosis haploid multicellular gametophyte 1n

Gymnosperm  Conifers vascular diploid  pollen (sperm) multicellular  dominant sporophyte sporophyte  dependent reduced gametophyte 2n mitosis  cones, seeds for reproduction meiosis fertilization 

mal e AP Biology

femal e

gametes 1n

spores 1n

mitosis

mitosis haploid multicellular gametophyte 1n

Angiosperm  Flowering plants vascular  pollen (sperm) diploid multicellular  dominant sporophyte sporophyte  dependent reduced gametophyte 2n mitosis  flowers, fruits, seeds for meiosis fertilization reproduction 

male gametophyte in pollen (haploid)

female gametophyte in ovary (haploid) AP Biology

gametes 1n

spores 1n

mitosis

mitosis haploid multicellular gametophyte 1n

Angiosperm: flowering plants

AP Biology

Angiosperm life cycle male gametophyte in pollen (haploid)

polar nuclei pollen grains

egg cell

fertilization

female gametophyte in ovary (haploid)

AP Biology

sporophyte in seed (diploid)

Flower  Modified shoot with 4 rings of modified leaves sepals Stamen  petals  stamens 

Stigma Style Ovary

Anther Filament

 male  pollen 

carpel  female  egg

AP Biology

Carpel

sepals petals stamens

Petal Ovule Sepal

carpel

Double Fertilization

Wha t’s the a da pti ve a dva nta ge?

pollen grain sperm cells

pollination

pollen tube

ovule

Endosperm (3n)

ovary endosperm (3n) pollen tube polar nuclei egg cell AP Biology

 food in seed  grains  beans  coconut

milk zygote (2n)

Seed & Plant embryo  Seed offers… protection for embryo  stored nutrients for growth of embryo 

cotyledons = “seed” leaves, first leaves of new plant AP Biology

seed coat

endosperm 3n cotyledons embryo

Identify the flower structures‌

AP Biology

Flower variations

AP Biology

Corn reproduction

seeds

flowers & seeds silk→stigma & style

AP Biology

female→carpel

tassel

pollen

male→stamens

Co-evolution: flowers & pollinators

How a bee sees a flower‌insects see UV light = a bulls-eye to the nectar

AP Biology

Angiosperm: fruiting plants

AP Biology

Other fruits‌

AP Biology

Fruit development  Peach, plum, apricot, cherry 

AP Biology

1 flower : 1 carpel : 1 ovary : 1 seed

Fruit development  Apple, pear 

AP Biology

1 flower : 5 carpels : many ovaries : many seeds

Fruit development  Citrus fruit ď ľ

AP Biology

1 flower : many carpels : many ovaries : many seeds

Fruit development  Raspberry, strawberry 

AP Biology

1 flower : many ovaries : many seeds

Seed dispersal  Plants produce enormous numbers of seeds to compensate for low survival rate ď ľ

vast amount of genetic variation for natural selection to screen

r-strategy

AP Biology

K-strategy

Any Questions??

AP Biology

2007-2008