pollination

pollination is the process by which

Pollen is placed on the stigma.

self pollinated is the

same flower

cross-pollinated is a

different flower

self-pollination is when pollen grain

is transferred from the anther to the stigma of the same flower

or

transferred from the anther of one flower to the stigma of another flower of the same plant

corss-pollination / out-crossing

When a pollen grain is transferred from the anther of the flower of one plant to the stigma of the flower of another plant

Successful pollination depends on

attraction of pollinators

what color don’t bee’s see and what does that mean

red

Other pollinators pollinate the red flower

Bees don’t pollinate red flowers

bull’ eye or landing strip

is visible to bees

butterfly pollinated flowers have

bright colors and flat landing platforms

moth pollinated flowers are

white or pale and heavily scented

open at night

what other insects pollinate

mosquito

beetle

fly

hummingburd pollinated flowers are

red and tubular

produce large amount of nectar with little odor

bat pollinated flowers are

open at night

light colored or white

strong smell

wind pollinated flowers

small

green

odorless

no nector

separated stamen and carpel ( separate plant or single plant)

Outcrossing is highly advantageous for plants …why many plants still use self-pollination often, even though cross-pollination is generally more advantageous for genetic diversity.

Self-pollination is favored in stable environments

offspring are more uniform and adapted to their environment (Self-pollination makes offspring genetically similar (uniform))

what promotes outcrossing

the separation of the female and male parts

dioecious and monoecious

“Maturation of male and female structures of the flower at different times(dichogamy) (promotion of cross-pollination)… meaning

• The anthers (male) and the stigma (female) don’t mature at the same time.

• This prevents self-pollination

dichogamy

the male and female parts of the same flower mature at different times

self-incompatibility

prevents self
fertilization

How does self-incompatibility prevents self
fertilization

pollen and stigma recognize each other as
being genetically related and the pollen
tube growth is blocked before it reaches
the embryo sac (incest)

5 environmental cues

1. Phase change to physiologically deal with
   flowering
   2. Light cue
   3. Chilling cue
   4. Hormonal cue
   5. Other cues
   

phase change

prepare a plant to
Respond to internal and external signals, it must
undergo a phase change

Four genetically regulated pathways to
flowering

The light-dependent pathway
2. The temperature-dependent pathway
3. The gibberellin-dependent pathway
4. The autonomous pathway

vernalization

period of chilling before
flowering

The Gibberellin-Dependent Pathway

Plant hormone gibberellin promotes flowering by
enhancing the expression of genes that allow
flowering

Autonomous pathway

Allows day-neutral plants (e.g., tobacco) to
“count” nodes and “remember” node location
before making the flower

node

area on the stem where lead is attached