chapter 5 flowers Flashcards
tulipomania
- wild tulips from central Asia
- monocots from the lily family
- “breaks” in tulips caused by a virus which breaks anthocyanin production
when did angiosperms appear in terms of evolution
- appeared in the fossil record during the cretaceous period, around 130 mya
- much species radiation during the cenozoic era
cretaceous period flowers looked similar to
water lilys
stamens are ______
males
- pollen producing
carpels are _______
females
-ovaries contain the egg
what are the four whorls flowers that make up flowers:
- sepals (calyx): protect plants as it is getting ready to bloom
-perianth: sepals + petals - petals (corolla): attract animals, perform insect pollination
- stames: made of anther and filament (androecium). holds pollen, male gametophyte
- carpels of stigma, style, and ovary (gynoecium): holds the egg
what does the ovary become after maturity?
fruit/container of seed
what does the ovule become after maturity?
seed
dicot flowers
- composed of parts in 4’s, 5’s, or multiples
monocot flowers
parts in 3’s or multiples
-ex. tiger lily
complete vs incomplete flower
complete flower: all flower whorls
incomplete: missing one or more whorls
describe a perfect flower
having male and female structures on ONE flower (synoecious)
imperfect flower:
unisexual
-ex. corn
monoecious
imperfect flowers on the same plant
dioecious
imperfect flowers on different plants
what are the three categories of perianth attachment?
- hypogynous: petals and sepals are arranged below the stem of gynoecium
- perigynous: ovary is at the center with petals and sepals on the rim
- epigynous: petals and sepals on the surface of gynoecium
radial symmetry
multiple planes of symmetry
bilateral symmetry
one plane, and a mirror image on each side
a cluster of flowers
inflorescence
what type of perianth attachment do sunflowers have?
- epigynous
- a sunflower is also an inflorescence
palynology
study of pollen
-used in archeology, paleontology, forensics
explain why hay fever is caused by inconspicuous flowers like ragweed instead of hay, or shower flowers?
ragweed is wind pollinated: they produce a lot of pollen and it spreads easily
microspore mother cell
- genetics
- what do they lead to?
- diploid
- undergo meiosis and lead to microspores
microspores
- genetics
- what do they develop into?
- genetics: haploid
- develop into multi-celled microgametophyte (pollen grain) which is haploid
exine
chemically resistant pollen outer layer
- resist decay
megaspore mother cell
- genetics
- what do they lead to after meiosis:
- genetics: diploid
- lead to four megaspores, three degenerate
megaspore
- genetics:
- what do they divide into:
- genetics: haploid
- divide to form a haploid megagametophyte (embryo sac)
what does the megagametophyte contain?
egg cell
what does the pollen land on?
the sigma
what is the advantage of stamens and carpels maturing at different times?
ensures cross pollination
- increases genetic diversity
what are the advantages and drawbacks of extreme specialization between pollinator and flower?
- advantage: no competition for pollinator
- drawback: if either went instinct the other would struggle to survive and reproduce.
what happens to the sperm as the pollen tube grows?
- the generative nucleus (1n) produces two un-motile sperm (1n)
discuss the fertilization process
one sperm fertilizes the egg creating a diploid zygote
what happens to the second sperm produced?
it fuses with two polar nuclei in the embryo sac to create a triploid (3n) endosperm
what is the function of the triploid endosperm?
provides energy for the embryo
post-fertilization
- perianth and stamen wither
- ovary expands to become fruit
- ovules become the seeds
- integuments of ovules become seed coat
