ch. 38 Flashcards
how to flowers reproduce with physically distant members of their own species?
insect
- Rhizanthese flower emits foul odor that attracts female blowflies to lay eggs on flower and deposit sticky pollen grains in process - pollinator doesn’t benefit, no food for hatched larva
how to most angiosperms lure insects
with nectar or pollen
mutualistic associations
both plant and pollinator benefit
symbiotic
living together
angiosperm reproduction is characterized by:
- flowers
- double fertilization
- fruit
flowers
reproductive shoots of angiosperm sporophyte
where do flowers attach to stem
receptacle
4 floral organs of flowers
- carpels - sporophyll
- stamens - sporophyll
- petals - sterile modified leaves
- sepals - sterile modified leaves
carpel
megapsporophyll with long style and sticky stigma to capture pollen
- base of style: ovary with 1+ ovules
what do fertilized ovules produce
seeds
pistil
single carpel or group of fused carpels
stamen
microsporophyll
- filament topped by an anther
- anther contains microsporangia (pollen sacs) that produce pollen
sepals
structures that resemble leaves
- enclose/protect unopened floral buds
petals
typically brightly colored to attract pollinators
complete flowers
contain all 4 floral organs
incomplete flowers
lack 1 or more floral organs
- petals or stamens
sterile flowers
lack stamens and carpels
unisexual flowers
lack either stamen or carpel
inflorescences
clusters of flowers
pollination
transfer of pollen from anthers to stigma
how can pollination occur?
wind, water, animals
what do most angiosperm species depend on for pollination?
animal pollinators
wind-pollinated species
- produced large amounts of pollen
- 20% of angiosperms
- grasses and many trees
- small, inconspicuous flowers that lack nectar/scent
pollination by bees
- 65% of angiosperms require insects, bees most important
- brightly-colored flowers w/ sweet fragrance
- nectar guides - UV markings that direct bees/insects to nectar-producing glands