Angiosperms Flashcards
What are angiosperms?
Flowering plants with fruits
What is special about angiosperms?
they are the most widespread and diverse plants
90% of all plants are angiosperms
What is a flower?
a unique angiosperm structure specialized for Sexual Reproduction
houses reproductive organs
promotes pollination
What is fruit?
mature ovary that surrounds seeds after fertilization
protects developing seeds
promotes seed dispersal
What are the four specialized shoots in a flower?
sepals
petals
stamens
carpels
What are sepals?
the "bud" usually green and leaf-like protects the developing buds some open and close with temperature and season they are sterile
What are petals?
big and brightly colored, to attract pollinators
some are smaller, often in species that use wind to spread pollen
they are sterile
What are stamens?
the male reproductive organs that make microspores (pollen, haploid gametophyte)
anther: makes pollen grains
filament: elevates anther to assist pollen dispersal
What are carpels?
female reproductive organs that produce megaspores (haploid gametophyte)
stigma: pollen landing site
style: elevates stigma to aid pollination, connects ovary
ovary: surrounds ovule/seed
What does radial symmetry allow?
pollinator can approach from any angle, meaning pollen can stick to animal anywhere
What does bilateral symmetry allow?
forces animals to approach from only one direction, focusing pollen concentration
What happens when the pollen grain lands on the stigma?
pollen tubes grow into ovary to deliver sperm
fertilization leads to development of the seed
initializes development of the ovary into fruit
What happens after fertilization?
the ovary matures in fruit tissue
What is dry fruit?
ovary becomes hard for protection, or specialized to allow wind dispersal of seeds
eg: beans, nuts, grains, grasses, dandelions
What is fleshy fruit?
ovary besoms soft, and is often sweet and edible to promote animal dispersal
eg: fruits and veggies
What are some adaptations to fruits to disperse seed?
wings (dry fruit), burrs (dry fruit), floating fruits, edible fruits
How did increased symbiosis allow angiosperms to dominate the planet?
evolved more partnerships to increase survival
Flowers: targeted pollen delivery
Fruits: very effective seed dispersal
Mycorrhizae: angiosperms have more elaborate root systems which boost interactions with fungi
How did better vascular tissues allow angiosperms to dominate the planet?
the vascular veins in angiosperms are much more efficient, employing vessel elements and sieve tube members
How did rapid life cycles allow angiosperms to dominate the planet?
gymnosperms often take years to develop, while angiosperms often take weeks
What are two subgroups of angiosperms clade?
monocots and eudicots
What are monocots?
have one embryonic leaf (cotyledons)
What are eudicots?
have two embryonic leaves
What are the characteristics of monocots?
one cotyledon: embryo has one leaf leaf vasculature: tends to be parallel vascular bundles: complex pattern roots: fibrous growth flower parts: occur in multiples of 3
What are the characteristics of eudicots?
two cotyledons: embryo has two leaves leaf vasculature: branched network vascular bundles: organized in rings roots: large, central taproot flower parts: occur in multiples of 4 or 5
