Features of Insect Pollinated Plants

Flowers (description/how useful)

Have large, brightly colored petals that advertise the flower;

Act as a landing stage and guide the insect’s movements to the anther or stigma

Scent (description/how useful)

Secreted from the petals to advertise the flower

Stigma (Description/how useful)

Large and sticky to collect pollen from visiting insects

Nectaries (Description/how useful)

(Glands) secrete a sugar solution (nectar) that’s attractive to insects as an energy source

Shape of Flower/ Position of nectaries (Description/how useful)

Positioned deep inside the flower so insects can only reach them by brushing past the anthers and stigma

Why would it make sense that wind pollinated flowers lack petals?

Because the petals would block pollen to get into wind pollinated flowers

What is cross pollination?

Transfer of pollen from an anther in a flower on one plant to a stigma of a flower on another plant

What does cross pollination promote?

It promotes genetic variation and evolution

What is definition by the term “hybrid vigor”?

A phenomenon that refers to the offspring of crosses between unrelated genetically plants that are healthy and tend to grow strongly

List the four strategies for promoting cross pollination rather than self pollination

-Adaptations to facilitate transfer of pollen from one plant to another by an outside agent

-Separation of anthers and stigmas/styles/ovaries in separate male and female flowers on the same plant

-Separation of anthers and stigmas/styles/ovaries in separate male and female flowers on different plants

-Anthers and stigmas maturing at different times

Protandry

anthers mature first

Protogyny

stigmas mature first

How likely can a Braeburn (S₉,S₂₄) apple act as a pollinator for Jonagold apples (S₂.S₃,S₉)?

Partially effective

How likely can a Golden Delicious (S₂,S₃) apple act as a pollinator for Jonagold apples (S₂.S₃,S₉)?

Incompatible

How likely can a Rome Beauty (S₂₀,S₂₄) apple act as a pollinator for Jonagold apples (S₂.S₃,S₉)?

Compatible

Self-incompatibility mechanisms increase… and it’s also…

genetic variability; a genetic basis of control (plants with same self-incompatibility can’t fertilize each other)

S-allele

encodes a pair of pollen and pistil phenotypes

What does the carpel/pistil reject?

Pollen that matches parent phenotype/genotype

What is the relation with the S-allele and pollen?

S-allele identifies pollen if it’s compatible, partially compatible, or incompatible

What does the S-allele decrease?

Inbreeding depression

Inbreeding depression

failure to thrive, increase in disease caused by inbreeding, promotes outbreeding

Identify whether the gametes and ovule would be compatible in A

Incompatible

Identify whether the gametes and ovule would be compatible in B

Partially Compatible

Identify whether the gametes and ovule would be compatible in C

Compatible

What structure produces pollen?

Anther of the stamen

What structure receives the pollen?

Stigma of the carpel/pistil

How does self-incompatibility increase genetic variation in plants?

It allows cross pollination to occur for genetic variation; hybrid vigor

What does self-incompatibility prevent?

Self-pollination

If only one pollen tube forms instead of two, the pollen is described as being…

Partially compatible

if neither grows a tube, the pollen is…

Incompatible