Angiosperms Flashcards
Angiosperm characteristics
Sp Div-1st Dominant vegetation -Siphonogomy -Double fertilization -Covered seeds -Flowers and fruit
Unique angiosperm features (4)
Xylem w/ vessel elements and phloem w/ sieve tubes
- Flowers and fruit
- Female gametophyte reduced to embryo sac
- Double fertilization
Flower
Modified reproductive shoot
- Stem=receptacle
- bearing 4 floral whorls
4 Floral Whorls
- Sepals
- Petals
- Stamens
- Carpels
Receptacle
Stem of flower (small disk)
-area where flower parts attach
Sepals
Outermost whorl
- Usually green
- Enclose other whorls in bud
- Prevent desiccation
- Calyx
Calyx
Collective term for sepals
Petals
2nd whorl
- Attraction
- Corolla
Corolla
Collective term for petals
Perianth
Collective term for calyx and corolla
-Non reproductive whorls
Stamens
- 3rd floral whorl
- Microsporophylls
- Filament-Stalk
- Anther
Anther
Stamen
- Sac w/ microsporangium
- Makes pollen
Microsporophylls
Leaf bearing microsporangia
-Stamen
Carpel
4th floral whorl
- Megasporophyll that has folded up and encloses ovule
- Stigma-receives pollen
- Syle-pollen tube grows down this stalk
- Ovary-houses ovule
- Monocot trend
2. Dicot trend
- Flower parts come in 3’s
2. Flower parts come in 4’s or 5’s
a-
1 or more whorls is missing
- uni sexual flowers
- Staminate or Pistilate
- Staminate
2. Pistilate
- Stamens but no carpel (male)
2. Carpels but no stamen (female)
Fruit
Mature ovary bearing seeds
-Develops after fertilization
Pericarp
Fruit wall
Exocarp
Outerlayer of fruit
-peel, skin, rind
Mesocarp
Middle layer of fruit
-Fleshy and yummy
Endocarp
Inner layer of fruit
-often hardened or “absent” (pit)
Layers of fruit (4)
Pericarp, exocarp, mesocarp, endocarp
Fleshy fruits
Fleshy mesocarp
Meant to be eaten so animals disperse seeds
-Berry-basic form of fleshy fruit
-Drupe
Drupe
Variation of berry w/ stony endocarp (pit), one seed
-cherry, almond, olive
Dry Fruits
Hard pericarp
- Endocarp usually “absent”
- Dehiscent or Indehiscent
Dehiscent (Dry) Fruit
Breaks open by itself to release seeds
- Many seeds per fruit
- Seed is unit of dispersal
Indehiscent (Dry) Fruit
Do not break open
- Fruit is unit of dispersal
- Fluff (dandelion)
- Helicopter wings
- Hooks and spines
- Achene and Samara
Achene
Basic indehiscent fruit (sunflower seeds)
-Shell is pericarp and seed is fruit
Samara
Winged achene
Aggregates
Fruits from an apocarpous flower
- Each carpel develops into fruit
- Yields aggregate of fruitlets
- Rasberry
Fusion
- Parts free
- Parts fused: conation and adnation
Parts Free
Parts not fused to each other
apo-
-Apocarpy-carpels aren’t fused (blackberry)
Conation
Fusion of like parts (petal to petal)
Syn- or sym-
Adnation
Fusion of unlike parts
-Stamens to petals is common
Actinomorphic Symmetry
Radially symmetric
-All planes can be divided into equal halves
Zygomorphic Symmetry
Bilateral symmetry
-Can be divided into equal halves of only one plane
Inflourescence
Group of flowers
Embryo Sac Structure
Reduced female gametophyte
- Reduced to 7 cells and 8 nuclei
- Lacks archegonia
- Egg apparatus
- Central cell
- Antipodal cells
Function of embryo cells
Synergids- attract pollen tube
- Egg cell gets fertilized to make embryo
- Polar nuclei-fertilized to produce endosperm
- Antipods-unknown
3 Steps of Reproduction
- Pollination
- Germination
- Double Fertilization