Flowers Flashcards
what isa flower
structure of modified leaves some of which are sporophylls
compound structure composed of different units of growth
what are whorls
different units of growth in a flower
what are the 4 whorls
- calyx
- corolla
- stamens
- pistil
what is a perianth
calyx and corolla together
what is the calyx
outermost whorl of a flower
protects iner layers
composed of sepals (most often green)
what is the corolla
layer immediately next to sepals
the petals of the flower
believed to be optimized for pollinator attraction
protects reproductive organs of the flower
what is the stamens
layer of male reproductive tissues
a filament topped with anther (where pollen is produced)
what is the pistil
layer of female reproductive tissue
innermost whorl
what is the pistil composed of
style (pollen receptacle)
stigma (structure between ovary and stigma)
ovary (contains ovules, can mature into fruit tissue)
types of flowers
staminate: male only
pistillate: female only
perfect: both
what is a dioecious flower
individual with both female and male flowers
what is a monoecious flower
individual with flower of a single sex
what is a pollinator
animal which moves pollen from the anther to the stigma on a flower
what is nectar
produced to attract potential polinators
sugar solution
where is nectar produced
in a nectary
what is the most common pollinator
bee
traits of beetle pollination
first pollinator group
plants are radially symmetrical with easily accessible pollen
traits of bee pollination
flowers have colours in UV spectrum that guide bees to the nectar
flowers can be tubular to allow passage of bees
significant nectar production
why is nectar sweet
attracts pollinators
traits of fly pollination
plants rely on their scent to attract flies
release a bad odor
traits of butterfly pollination
plants are large or in cluster to provide landing platform
brightly colours with potential necatar guides
prolific nectar produced
traits of bat pollination
plants rely on scent to attract pollinators
very strong floral scent
large number of anther
are radially symmetrical or tubular/funnel shaped
traits of bird pollination
flowers need to be colourful (mostly red)
very abundant nectar
long tubular structure
stamen oriented to come into contact with birds as they feed
what are specialist pollinators
plants that have adapted to be pollinated by a single species of pollinators
traits of bee orchid pollination
release same pheromones as the female bee of the species
flower looks like the female bee
attracts male bees thinking theyre copulating
traits of wind pollination
wind moves pollen from flower to flower many small flowers no scent or nectar lots of pollen staminate and pistillate flowers
what are the limitations on pollination success
pollen viability
pollen incompability
self-compability
what is pollen viability
proportion of pollen grains capable of germination
not all pollen grains will be able to fertilize egg
what is pollen incompability
not all pollen can fertilize all species
what is self-incompatibility
the inability of a plant to self pollinate
pollen land on stigma but its not signalled to germinate
problems with self fertlization
- no sexual reproduction, no mixing of gametes= clone
what is a fruit
can be fleshy or hard and dry
produced by ovary tissues
what is seed dispersal
movement of seeds away from the parent plant
why do seeds need to move away from the parent plant
if it germinates below parent plant, it will compete with parent plant
what are the mechanisms for seed dispersal
wind
animals
water
expulsion
what is wind disperal
seeds that require wind to disperse
seeds of wind dispersal
small
have wing like structure of feathery structures to catch wind
what is animal dispersal
interaction with animals necessary for dispersal
seeds dispersed in poop
seeds of animal disperal
covered by fleshy ovary to attract animals
hooks or abrasive material to attach to animal coats
what is water dispersal
seeds designed to float on water and transport along watercourses
seeds of water dispersal
hollow center to allow floating
what is expulsion dispersal
fruits explode and disperse seeds
seeds in expulsion dispersal
fruits under pressure
drying out releases seed
what is kin care
seeds which germinate below the parent tree are fed by mother tree through myocorrhizal networks
