Lecture 7 DA Flashcards
Why are nightflowers usually white?
White is most fluorescent to moonlight.
What is a sepal?
Petal like growth that protects the flower as it develops. The outermost covering.
What are petals?
Used to attract pollinators via colour and fragrance. Larger than sepals.
That is a perianth?
Collective term for petals and sepals.
What is a stamen?
The flower’s male unit. Made of a filament, with an anther on its tip, covered in pollen.
What is a carpel?
The flower’s female unit. Made of a stigma at the tip, and a style leading to an ovary.
What is a tepal?
When a petal and sepal are indistinguishable, as in tulips and lilies.
What is a calyx?
Where sepals join to the flower.
What is a corolla?
Where petals join to the flower.
Why do some flowers have fused petals?
To filter which pollinators can have access.
What fuses in fused flowers?
Corollas.
What are the two symmetries of flowers? What are the petals like in each?
Actinomorphic
Star shaped, radially symmetrical. Petals are all similar.
Zygomorphic
Yoke-shaped, bilaterally symmetrical. Petals are typically different.
Can there be multiple flowers on one stem, or is there only a single one?
Can have single or multiple.
What is a polypetalous, sympetalous, and epipetalous flower?
Polypetalous
Petals attached to receptacle and free.
Sympetalous
Petals are united.
Epipetalous
Stamens attached to the petal.
What do carpels join to?
Gynoecium.
What do stamens join to?
Androecium.
What is a carpel?
Stigma + ovary.
What is an ovary?
Ovule + protective wall.
What are advanced flowers versus primitive flowers?
Advanced
Carpels are fused, ie. the ovary is fused to the stigma.
Primitive
Carpels are free and spirally arranged, cone shaped.
What are the three ovary positions?
Epigynous - ovary below the floral parts.
Perigynous - ovary within the floral parts.
Hypogynous - floral parts below the ovary.
Why are anthers sometimes above the stigma?
So that pollen might fall into it.
What are the two floral formulas?
K? C? A? G(?)
Also P(?) A? G(?) if petals and sepals indistinguishable
K – sepals (if >10, use ∞)
C – petals
A – stamens
G – carpels
P – perianth
If petals are fused to stamens, draw a line above, connecting A to C to indicate fusion
If epigynous, underline the G, if above, overline G.
What are some causes of failed flowering (6)?
Depends on the species
Maturity
Environmental, light availability, temperature
Soil nutrition
What wavelength is more easily absorbed by chlorophyll and by flowers?
Blue light more easily abosrbed by chlorophyll, while red for flowers.
What are the three flower types?
Hermaphroditic - plant has flowers with both male and female units.
Dioecious - plant has either male or female flowers on seperate plants.
Monoecious - plant has both male and female flowers.
Can plants sex change?
Only dioecious can depending on development.
What is an advantage of monoecious and dioecious flowering?
Avoids inbreeding and increases genetic diversity, but more difficult to be pollinated.
What does self pollination involve? What about cross pollination?
Self pollination
Is inbreeding, involves only one plant.
Cross pollination
Is outbreeding, involves 2 plants.
What are the characteristics of outbreeder flowers (11)?
Self incompatible Many flowers Large flowers Bright colours Nectar rewarding Nectar guides (ie. UV light) Scented Anther distant to the stigma Lots of pollen Style extended away from the flower Stigma is defined
What are the characteristics of inbreeder flowers (11)?
Self compatible Few flowers Small flowers Dull colours No rewards No guides Unscented Anther close to stigma Fewer pollen Style within flower Stigma undefined
How do cleisogamous flowers pollinate?
The flowers remain closed, and are self pollinated.
How do chasogamous flowers pollinate?
Flowers open, relies on external source for pollination.
How do entomophilous flowers pollinate?
Relies on insects. Flowers are showy and rewarding.
How do anemophilous flowers pollinate?
Wind pollinated. Flowers are small, arent showy.
What are biotic and abiotic vectors for pollen (percentages)?
Biotic Animals 80% Abiotic Wind 19% Water 1%
What pollination types do entomophilous and anemophilous flowers fall under?
Chasogamous flowers.
