Angiosperm Reproduction and Biotechnology

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Slide 1

Angiosperm Flowers

Angiosperm flowers can attract pollinators using visual cues and volatile chemicals.

Many angiosperms reproduce sexually and asexually.

Symbiotic relationships are common between plants and other species.

Since the beginning of agriculture, plant breeders have genetically manipulated traits of wild angiosperm species by artificial selection.

Slide 2

Flowers, double fertilization, and fruits are unique features of the angiosperm life cycle

Alternation of Generations:

Diploid (2n) sporophytes produce spores by meiosis 2n ---> n these spores (n) grow into haploid (n) gametophytes.

Gametophytes produce haploid (n) gametes by mitosis fertilization of gametes produces a zygote = sporophyte cell (2n).

Slide 3

In angiosperms, the sporophyte is the dominant generation, the large plant that we see.

The gametophytes are reduced in size and depend on the sporophyte for nutrients.

The angiosperm life cycle is characterized by “three Fs”: flowers, double fertilization, and fruits.

Slide 4

Stamen

Anther

Filament

Stigma

Carpel

Style

Ovary

Anther

Pollen tube

Germinated pollen grain (n)

(male gametophyte)

Ovary

Ovule

Embryo sac (n)

(female gametophyte)

Egg (n)

Sperm (n)

Zygote

(2n)

Seed

Seed

Embryo (2n)

(sporophyte)

Simple fruit

Germinating

seed

Mature sporophyte

plant (2n)

(b) Simplified angiosperm life cycle

Key

Receptacle

Sepal

Petal

(a) Structure of an idealized flower

Haploid (n)

Diploid (2n)

FERTILIZATION

An overview of angiosperm reproduction

Slide 5

Stamen

Anther

Filament

Stigma

Carpel

Style

Ovary

Receptacle

Sepal

Petal

Structure of an idealized flower

Slide 6

Anther

pollen

Pollen tube

Pollination

Germinated pollen grain (n)

(male gametophyte)

Ovary

Ovule : Double Fertilization

Embryo sac (n)

(female gametophyte)

Egg (n)

Sperm (n)

Endosperm

(3n)

Zygote

(2n)

Seed

Seed

Embryo (2n)

(sporophyte)

Simple fruit

Germinating

seed

Mature sporophyte

plant (2n)

Angiosperm Life Cycle

Key

Haploid (n)

Diploid (2n)

FERTILIZATION

Slide 7

Flower Structure and Function