lecture 17, angiosperms Flashcards
what is the significance of Angeion?
largest phylum of photosynthetic organisms
when did angiosperms first appear?
140 mya
what are the distinctive features of angiosperms?
flowers and fruits
the flower contains:
a determinate shoot, sporophylls- sporangium-bearing leaves, carpel (contains ovules), inflorescences or solitary flowers
what are sterile appendages?
sepals (calyx) and petals (corolla)
-attached to receptacle
what is a perianth
sepals and petals together
what is a tepal
undifferentiated perianth
What are the fertile parts of an angiosperm?
gynoecium/carpels. contains:
- ovary
- style
- stigma
androecium/stamens. contains:
- filament
- anther
what are the 4 whorls of an angiosperm?
sepal, petal, stamen, carpel
what can flowers be clustered into?
inflorescences
what is a penduncle?
stalk of cluster or solitary flower
what is a pedicel?
stalk of individual flower in a cluster
what compound does the hemlock plant produce
umbel
what are ovules partitioned into?
locules
what are inflorescences?
many flowers as opposed to one single flower
what is a locule?
a compartment, a level of organization within the ovary
where are vascular bundles found in angiosperms?
in ovary walls
what are the variations in flower structure? plant structure?
flowers: perfect and imperfect
plants: monoecious and dioecious
what are perfect flowers?
bisexual/hermaphrodite, both stamens and carpels
what are imperfect flowers?
unisexual, either staminate or carpellate (pistillate)
what is a monoecious plant?
has both sets of flowers
what is a dioecious plant?
female and male plants
what is a hypogynous flower?
sepals, petals, and stamens below ovary
what is a perigynous flower?
SPS fused to form cup-shaped extension of receptacle, hypanthium
what is an epigynous flower?
SPS above the ovaries
What is Epigyny
sepals, petals and stamens arise from top of ovary
what is perigyny
flowers SPS attached to hypanthium
what does a pollen grain contain?
sperm cells and a vegetative nucleus
microspores are found within the …
anther
megaspores are found within the…
ovule
how many microspores are within each anther?
4 - each divides into a microgametophyte after meiosis
how many megaspores are within an ovule?
4 haploid megaspores result after meiosis. 3 disintegrate and 1 develops into megagametophyte
what does each microspores divide into?
a vegetative, or tube cell and generative cell - an immature microgametophyte / pollen grain
what happens during germination?
generative cell divides into two sperm cells (mature microgametophyte)
the 4th female megaspore develops into …
a megagametophyte
a zygote is formed by..
the 1st sperm fusing with the egg
what does the 2nd sperm cell do?
fuses with 2 polar nuclei –> triploid primary endosperm nucleus - nutritive tissue of embryo
the embryo develops in what
within the embryo sac
what does the integument develop into?
the seed coat
what are the 4 groups angiosperms are divided into?
- dicots
- monocots
- magnoliid
- basal angiosperms
traits of magnoliids
- 3rd group of angiosperms
- one family: magnoliaceae
- representative of early angiosperms
- simple flowers
what is ANITA?
Amborella, Nymphaeales and Iliciales, Trimeniaceae-Austrobaileya
