CH 30: Angiosperms Flashcards
What are the defining features of Angiosperms?
- Flowers and Fruits
- Enclosed seeds
- Seeds within fruits
- Seed endosperm
What was Darwin’s “Abominable Mystery?”
Origin of Flowering Plants
-how did they get so diverse so quick?
Why were Angiosperms so successful?
- Complex vascular tissues; wide vessels for efficient transport to grow big
- Broad leaves for photosynthesis; thick cuticle prevent water loss; abscission leaves fall off
- Fast life cycle (die off in winter and come back through seeds)
- Fruit protects seeds; dispersal
- Coevolution led to efficient reproduction
What are the key characteristics of Angiosperms?
- Efficient vessels move water quickly
- Flowers for sexual reproduction
- Stigmatic germination and double fertilization
- 3n Endosperm - provide nutrition for seeds
- Fruit: protect & disperse seeds
What is the reproductive structure of the angiosperm and what are the organs?
Flowers are the reproductive structure of Angiosperms
Four organs:
1) Sepals: green outer layer of flower (protection)
2) Petals: often colorful (attraction)
3) Stamens: produce pollen
4) Carpels (pistil): produce ovules
What are the compenents of the Carpel and Stamen?
Carpel (pistil) (female flower parts)
1) Stigma
2) Style
3) Ovary
Stamen (male flower parts)
1) Anther
2) Filament
What occurs in the ovary?
1) Ovules inside of ovary develop into embryos
2) The embryos develop into seeds
Ovary protects the ovules
What is the anatomy of the pistil (carpel)?
1) Stigma: receives/recognizes pollen
2) Style: long portion between stigma & ovary
3) Ovary: enclose/protects ovules (develop into fruit)
What is the anatomy of the stamen?
1) Anther: sac-like structures where pollen is produced
2) Filament: slender stalk to support anther
What are the types of angiosperm flowers?
1) Complete Flowers
2) Incomplete Flowers
3) Perfect Flowers
4) Imperfect Flowers
What are Complete Flowers?
-Contain all 4 flower organs (sepals, petals, stamens, pistil)
What are Incomplete Flowers?
-Flowers that lack one or more organ
What are Perfect Flowers?
-Contain both male/female reproductive structures
What are Imperfect Flowers?
-Flowers that lack one or more reproductive organs
If you’re a perfect flower are you a complete flower? Is an imperfect flower an incomplete flower?
Perfect flower not automatically complete flower
Complete flower automatically perfect flower
Imperfect flower automatically incomplete flower
Incomplete flower not automatically imperfect flower
What is angiosperm double fertilization?
One sperm fertilizes an egg (2n)
One sperm fertilizes with 2 gametophyte nuclei to form endosperm (3n)
What are the major clades of angiosperms?
Monocots
-one cotyledon (seed leaf)
Eudicots
-two or more cotyledon
What are the features of Monocots?
Root
-root xylem and phloem in a ring
Stem
-vascular bundles scattered in stem
Leaf
-leaf veins form a parallel pattern
Flower
-flower parts in threes and multiples of three
What are the features of Eudicots?
Root
-root phloem between arms of xylem
Stem
-vascular bundles in a distinct ring
Leaf
-leaf veins for a net pattern
Flower
-flower parts in fours or fives and their multiples
What is coevolution and how does it explain angiosperm diversification?
- When two or more species of organisms (flowers/pollinators) influence eachother’s evolutionary pathway
- Explains diverse forms of flowers/fruits to accomplish pollen/seed dispersal
How did pollination coevolve?
- Foster genetic variability
- attact pollinators using color, odor, shape, size
What are pollination syndromes?
Flower traits that have coevolved in response to natural selection with pollinators
-Bees, Butterflies, Moths, Birds, Bats
What are the pollination syndromes for bees?
- Flolowers are all colors but red
- Flowers are fragrant
- Flowers have lot of nectar/pollen
What are the pollination syndromes for butterflies?
- Flowers are all colors
- Flowers have light scent
- Flower has landing pad
- Tubular tongue so nectar in deep tube
- Nectar guide patterns
What are the pollination syndromes for moths?
- Flowers are white/bright/open at night
- Flowers have musky odors
- Feed with long thin tongue so nectar in deep tube
What are the pollination syndromes for birds?
- Color visionso flowers often red
- Require perch so flower is strong
- Flower has no smell
- Flower has alot of nectar
- Hummingbirds hover so their flowers dangle
- Flowers have pro-bird/anti-insect adaptations
What are the pollination syndromes for bats?
- Color blind so flowers have light reflective colors
- Flower has strong odor
- Active at night so flower opens at night
- High food requirement so flower has alot of nectar
- Navigate by echolocation so flower on tree trunks
- Bats travel further so pollen spread farther apart
What are the abiotic pollination syndromes?
Wind
-reduced flowers, no petals to get in way of wind
Water
-rare
What is the job of fruit and how did they adapt?
Job is to protect seeds and aid in dispersal
Adapted to:
1) Attract animals to eat it
2) For wind dispersal
3) Attach to animal fur
4) Float in water
What are secondary metabolites and how are they related to pollination?
Synthesis of molecules that are not essential for cell structure/growth
-encourage polinators to visit flower
What secondary metabolites are produced by angiosperms?
1) Terpenes and terpenoids
- rubber, amber, turpentine
2) Phenolics
- cinnamon, nutmeg, vanillla
3) Alkaloids
- nitrogen containing (addictive)
What are the types of abiotic seed dispersal?
1) Gravity - drop to ground
2) Wind - float away
3) Water - float away
What are the types of biotic seed dispersal?
1) animal (external)
2) animal (internal)
How did seed-dispersal coevolve?
- Sweet/juicy fruits to be eaten
- Signal ripeness with color change
What are seeds?
protective coat enclosing an embryo and food reserves
-removed plant dependence on water
What is vivipary?
growth of seed when still attached to maternal plant
- very rare
- drops from tree ready to grow
What is seed dormancy?
When seed doesn’t germinate until conditions are favorable
What is a soil seed bank?
storage of seeds (usually dormant) within soil
- transient: seeds stay in soil <1yr
- short-term persistent: seeds stay in soil 1-5yrs
- long-term persistent: seeds stay in soil >5yrs
What is the result of human influence on Angiosperm diversification?
Humans have selected for a few plants for foods/crops we like
- causing these plants to be dominant
- reduces biodiversity
- invites problems (pests, famine, disaster)
What are the lasting effects of human influence on angiosperm diversification?
Plants are renewable resource but plant diversity is not
-rate of loss faster than any other time in history
