Transcript Gymnosperms and Angiosperms

Angiosperms
• Angiosperms are the most diverse and
geographically most widespread plants
• Have flowers and fruits with seeds
• Two classes:
• 1. Monocotyledones (monocots)
• 2. Dicotyledones (dicots)
• Insect pollination tightly linked to evolution of
the flower.
Angiosperms
• Ecological Success of the
Angiosperms
– Able to survive in a greater variety of
habitats than any other group of plants
– Faster life cycle - mature more quickly than
ferns or gymnosperms
– Most produce greater number of seeds per
year than gymnosperms
– Animals aid in pollination - can survive as
small scattered populations
Angiosperms
• Fruits for seed dispersal
• Most diverse and specialized group
– perennials or annuals
– Leaves of angiosperms are thin blades, diversity of
shapes, better adapted for light interception.
– Xylem of angiosperms contains wide-bore vessels,
allows faster conduction of water.
– Woody tissue of angiosperms more complex and
highly specialized
Angiosperms
From the Greek
Angeion = vessel
Sperma = seed
Monocot vs. dicot
• As the zygote grows into the embryo,
the first leaves of the young sporophyte
develop and are called as cotyledons
(seed leaves)
• Monocots have one cotyledon (corn,
lily, etc).
• Dicots have two cotyledons (bean, oak,
etc).
Monocot vs. dicot
• Number of cotyledons: one vs. two
Monocot vs. dicot
• Leaf venation pattern:
• Monocot is parallel
• Dicot is net pattern
Monocot vs. dicot root
• Monocot: Fibrous root
• Dicot: Tap root
Monocot vs. dicot
• Flower parts:
• Monocot: in groups of three
• Dicot: in groups of four or five
Monocot vs. dicot
• Monocot: Vascular bundle position:
• Dicot: arranged in a circle
2 groups of Angiosperms
• Monocot
Summary:
Monocot vs. dicot
Plants
1
bud
leaf
flower
5
4
2
stem
roots
3
Leaves:
• Make food for plants which is
sugar
• Take in carbon dioxide
through tiny openings in the
leaves
Roots:
• Hold the plant in the ground
• Take in water and nutrients for
the plant’s growth
The Stem:
• holds up the plant parts
above the ground.
• has tiny tubes to transport
water and nutrients to the
plant’s parts.
What about flowers?
• Flowers are made of petals.
• Petals attract insects to the flower.
• The flower makes seeds.
The life cycle of a plant
2.Leaves 3. More leaves
start to
grow. Flower
1.Roots
grow.
buds appear. 4. The
grow from
flowers open.
a seed.
Xylem & Phloem
• Vascular tissue that
moves water, minerals
and nutrients from the
roots to all parts of the
plant
Angiosperm Basics
• all have flowers
• flowers are
reproductive
organs
• They make up
around 80 percent
of all the living
plant species on
Earth.
c
male part of flower
• Angiosperms have
male sex organs
called stamens.
• On the end of the
stamen is the
anther. This is where
pollen is made.
• The pollen has to be
taken to the pistil or
the female part of the
flower.
female part of flower
• The pollen is left on the stigma at the
end of the pistil.
• The stigma carries the pollen down a
tube called the style to the ovary.
• eggs are fertilized and develop into a
seed in an ovary that is usually in a
flower.
Pollination
• Some plants can cross pollinate.
This means they can pollinate
themselves.
• Others rely on pollinators.
• Most species offer a nectar or
pollen reward to insects or birds to
attract them to the flowers. The
colors and scents of flowers often
assist pollinators in finding plants
From seed to Fruit
After fertilization the
embryo begins
growing. The result is
a seed.
• The ovary {tissue
immediately surround
the seed or seeds}
will develop into a
fruit
• Every angiosperm,
produces some type of
fruit
• Fruit serves to
disperse the seeds the
plant produces, which
is very important.
• When a plant flowers and
produces seeds, it also
produces something else we all
like -- fruit. As you learned,
when the ovary ripens, it
swells and forms a protective
covering around the seeds.
This protective covering, or
fruit, often finds its way on top
of cereal, ice cream, a salad, or
just a tasty snack.
Seeds
• The seed's plant-parts are not "true"
leaves, stem and roots, but are
effective enough to the launch the plant
into its growth phase when true leaves,
roots and stems appear.
Seeds
• Hidden inside every seed is a tiny embryonic
plant complete with root, stem and leaves, ready
to sprout when suitable conditions appear
What is their job?
make food from light, air
and water.
Petals
get water from the soil.
Stems
help the plant stand up.
Leaves
attract insects.
Roots
Flowers
take food and water to the
leaves
make seeds.