Download Ovary

FLOWERS and FRUITS
Angiosperms is the name given to plants that produce flowers.
The flower contains the reproductive organs of a plant.
Male Reproductive Organ
STAMEN
Anther – Produces sperm
nuclei by meiosis.
Sperm nuclei are enclosed
by pollen grains.
Filament - holds the anther
up.
Female Reproductive Organ
PISTIL
Stigma - Top of the pistil,
sticky surface for pollen to
stick.
Style - connects the stigma
to the ovary.
Ovary – contains the ovules
(eggs).
Pollination/Fertilization
1. Pollination occurs
when a pollen grain
lands on a stigma.
2. A pollen tube grows
down the style into the
ovary and enters an
ovule.
3. A sperm travels down
the tube to fertilize one
egg. This is called
fertilization.
4. The resulting embryo
then develops into
a seed.
Pollen Sacs of the
Lily Anther
The pollen Tetrads in the
Lily Anther formed by the
meiotic division of the
microspores in the pollen
sacs. They will mature into
fully formed pollen grains.
The Lily Ovulary Megaspore Mother Cell
It is a large diploid
cell that undergoes
meiosis to form four
haploid megaspores.
The second meiotic division in the lily ovulary
results in the formation of four haploid
megaspore nuclei. They are not separated by cell
walls in lilies.
WHAT IS A FRUIT?
1. Fruits come in all shapes and sizes.
2. It is the result of the thickening of the ovary wall which functions to protect the seeds inside and to aid
in seed dispersal.
3. The tissue of a fruit may be fleshy and contain stored sugars and starches, i.e., apples and pears (the
receptacle is the edible part).
4. They may be dry and hard and remained attached or fused to the ovary wall, i.e., walnuts and hazelnuts.
5. Many “vegetables” such as squash, eggplant and cucumbers are really fruits.
AGGREGATE
FRUITS:
Consists of a number
of matured ovaries formed
in a single flower and arranged
over the surface of a single
receptacle. Individual ovaries
are called fruitlets.
THREE
MAJOR
TYPES
of FRUITS
SIMPLE
FRUITS:
Developed from a
single matured
ovary in a single
flower.
MULTIPLE
FRUITS:
Consists of the matured
ovaries of many flowers
more or less united into a
single mass. Most are also
accessory fruits which means
they have some other flower
part united with the ovary.
1. Two classes of angiosperms:
monocots and dicots . Monocots
have one cotyledon and dicots have
two.
2. Cotyledons (seed leaves) are the first
leaves produced by plants.
3. They are found in the seed or plant
embryo.
4. They provide stored food and
nutrients for the growing plant until
the true leaves can grow and begin
the process of photosynthesis.
5. Monocots and dicots have physical
characteristics by which they can be
identified: number of floral parts, by
the array of their leaf veins, by their
number of pores or furrows on the
pollen grain and by the distribution of
their vascular bundles.