Transcript Seed Plants

Botany - Ch 5
Recall that seedless plants were either nonvascular
or vascular… either way they did NOT produce
seeds
Seeds can be found everywhere…acorns,
dandelion seeds, kernels of corn, even peanuts!
Seeds are very common and often overlooked.
Seed plants are also vascular plants and are
divided into 2 groups
Gymnosperms – bear their seeds on the surface
of a cone (pine trees = pine cones)
Angiosperms – produce fruit or flower that
protects the seeds (wildflowers or apple tree)
Seed plants are not like mosses & ferns they do
NOT need water for reproduction
As a result they can live just about anywhere.
Adaptations that allow seeds to reproduce without
water include: flowers or cones, pollination, and
embryo protection in seeds
The gametes (called gametophytes in plants) are
the sex cells that grow and mature in cones or in
flowers
Cones are found in gymnosperms
Flowers are found in angiosperms
In seed plants the entire male gamete is contained
in a pollen grain.
This pollen grain must be carried to the female
gamete by wind, insects, birds, and sometimes
even bats.
The transfer of pollen to the female is called
pollination
A seed is an embryo (fetus) of a plant that is
encased in a protective covering and surrounded
by a food supply that provides nutrients as the
embryo grows
A seed coat surrounds the embryo and keeps it
from drying out
Seeds may have special tissues or structures that
aid in their dispersal. Some are textured so they
stick to fur or feathers of animals. Some seeds are
eaten and dispersed after digestion
The embryo can stay in the seed for weeks,
months, or even years
Gymnosperms include four groups:
Gnetophytes
Cycads
Ginkgoes
Conifers
These plants all reproduce with seeds that are
exposed on cones
Gymnosperms means “naked seed”
There are about 70 gnetophyte (nee-toh-fy-tuh)
species
They are found in mostly desert and tropical forest
habitats
There are about 300 species of Cycads (si-kad)
They are beautiful palmlike plants that reproduce
with large cones
They are found in tropical places such as Mexico,
Florida, Asia, Africa, and even Australia
They typically grow very slowly and live very long
They are sometimes confused with and mistaken
for palms or ferns, but are only distantly related
Ginkgoes (ging-kohs) have only one species today
It is one of the oldest seed plant species today
Ginkgoes are often planted in city settings in the
US where their toughness and resistance to air
pollution make them popular shade trees
Conifers are the most common gymnosperms with
more than 600 species including pines, spruces, firs,
cedars, and redwoods
The dominant plants over huge areas of land
They are more resistant to freezing and are found in
all habitats
Thrive in a wide variety of habitats such as
mountains, sandy soil, cool areas, dry places, warm
habitats
Their leaves are long and thin which reduces the
surface area and are also covered by a waxy layer
that limits the amount of water that can be lost by
evaporation
Most conifers are evergreen meaning they retain
their leaves all year. Needles can stay on a tree for
2-14 yrs & they are gradually replaced so that the
tree is never bare
Flowering plants are called angiosperms
Flowering plants have quickly became the
dominate type of plant life on Earth. The vast
majority of living plant species reproduce with
flowers
Angiosperms have reproductive organs called
flowers, which attract animals that transport
pollen from flower to flower making pollination
more efficient than gymnosperms
Flowers contain ovaries that surround and protect
seeds. After pollination the ovary develops into a
fruit which protects the seed.
The fruit is a thick wall of tissue surrounding the
seed. When the fruit is eaten by animals seeds can
be dispersed many miles away from where they
originated
The seed leaves of a plant embryo is called a
cotyledon
Angiosperms can be monocotyledons
(MONOCOTS) or dicotyledons (DICOTS)
Monocots - have 1 part to the seed; parallel veins;
flowers have petals in multiples of 3; the veins are
scattered throughout the stem; and they have
fibrous roots; corn, wheat, lilies
Dicots – have 2 parts to the seed; branched veins;
flower petals in multiples of 4 or 5; veins are
arranged in a ring around the stem; and has 1 main
taproot; clover, tomatoes, oaks, daisies; roses
Woody and herbaceous plants: grouped according
to their stems.
Woody plants are made primarily of cells with
thick cell walls. This includes trees, shrubs, vines
(grape and ivy), blueberries, and roses.
Herbaceous plants have stems that are smooth
and nonwoody such as dandelions, sunflowers,
and petunias
Annuals – grow, flower, produce seeds & die all in
one growing season (ex: marigolds, pansies,
wheat, cucumbers)
Biennials – complete life cycle in 2 growing
seasons. The 1st year they grow roots, stems, and
some leaves – 2nd year they grow flowers & seeds
(ex: parsley & celery)
Perennials – live through many years; most have
woody stems such as palm trees, maple trees,
honey suckle. Herbaceous plants such as grass &
asparagus that die in the winter but come back in
the spring
Where can seeds be found?
What are the 2 types of seed plants?
How are seed plants different from mosses &
ferns?
What are some adaptations seed plants have that
allow them to reproduce?
What is a gamete?
What is pollen?
When pollen is transferred what is that called?
What is a seed?
How long can an embryo stay in a seed?
What do gymnosperms carry their seeds on?
What are the 4 types of gymnosperms?
Where do you find gnetophytes?
What do cycads look like?
How many different types of ginkgoes are there
today? Why are they often planted?
What is a conifer? And where do you find them?
What is special about conifer leaves?
Where do you find seeds in a flowering plant?
What is another name for a flowering plant?
What is the fruit of a flowering plant?
What is a monocot?
How many flower petals does it have? What do the
roots look like?
Examples of monocots?
What is a dicot?
How many flower petals does it have? What do the
roots look like?
Examples of dicots?
How can you tell of a plant is a woody plant or an
herbaceous plant?
Give an example of woody plants? Of herbaceous
plants?
What is an annual? & Give an example
What is a biennial? & Give an example
What is a perennial? & Give an example