This document provides an overview of plant characteristics and classification. It discusses the key parts and processes of seed plants including angiosperms and gymnosperms. Seed plants are classified into gymnosperms, which produce naked seeds, and angiosperms, which produce seeds within fruits. Angiosperms undergo pollination and fertilization to produce seeds which are then dispersed by fruits. This allows for sexual reproduction through cross-pollination and asexual reproduction through vegetative propagation. Seed plants are essential to humans and ecosystems.

1. Chapter 5 Plants
Section 1
An Overview of Plants

2. Plant Characteristics
Most have roots or root like structures to hold
them in the ground.
Are adapted to nearly every environment on
Earth.
All plants need water.
All are many-celled.
Nearly all contain chlorophyll.

3. Plant Cells
A cell membrane, cell wall,nucleus, and other
cellular structures.
Cell walls provide structure and protection for
plant cells.
Most plant cells contain chlorophyll (green
pigment that gives plants their color).
Chlorophyll is needed for photosynthesis.
Chlorophyll is found in the chloroplast.

4. Plant Cells
Most have a large, membrane-bound structure
called the central vacuole that takes up most of
the space inside of the cell.
Central vacuole regulates water content of cell.
Also stores pigment that makes some flowers
red, blue, or purple.

5. Protection and Support
Cuticle – waxy, protective layer secreted by
cells onto surface of plant and slows the loss of
water.
Cellulose – chemical compound found in cell
walls that connect to make long fibers to help
provide support and structure.

6. Evolution of Plants
Between 260,000 and 300,000 species have
been identified (are probably many more).
Ancestors of plants was probably green algae.
Oldest fossil plants are about 420 million years
old.
Cone-bearing plants (pine trees) – 300 million
years ago
Flowering plants – 120 million years ago (but not
for sure).

7. Classification of Plants
Vascular – plants with tubelike structures that
carry water, nutrients, and other substances
throughout the plant.
Nonvascular – do NOT have tubelike structures
and use other ways to move water and
substances.
All plants have a binomial nomenclature.

8. Chapter 5
Section 2
Seedless Plants

9. Seedless Nonvascular Plants
Do NOT grow from seeds
No roots – have rhizoids (threadlike structures
that anchor them into the ground)
Only 2-5 cm tall
No tubelike structures to move water through it
No flowers or cones
Ex. – moss, liverworts, hornworts

10. Examples of Seedless Nonvascular
Mosses
– Most seedless
nonvascular are
classified as this
– Leaflike growths are
arranged around a
central stalk.
– Grow on tree trunks
and rocks

11. Examples of Seedless Nonvascular
Liverworts
– Means “herb for
the liver”
– Used as medicine
long ago
– One-celled rhizoids

12. Examples of Seedless Nonvascular
Hornworts
– Less than 2.5 cm
in diameter
– Flattened body
– Only 1 chloroplast
in each cell

13. Reproduction of Nonvascular Plants
Gametophyte (sex organs) – structure that
forms gametes (sperm cells and egg cells).
Sperm are formed in the male gametophytes
and eggs are formed in the tips of female
gametophytes.
Sperm is splashed by water onto female
gametophytes and swims to the eggs.
Sperm joins with an egg and a zygote is formed.

14. Reproduction of Nonvascular Plants
Zygote develops into a long, thin stalk from the
tip of the female gametophyte.
A capsule forms at the top of this stalk.
Spores are formed inside the capsule.
The capsule and the stalk are called the
sporophyte.
Capsule bursts open and spores are forced out.
If spores land on a moist surface, they will grow
into another plant.

15. Nonvascular Plants and the
Environment
Spores of mosses and liverworts are carried by
the wind and will grow into plants if enough
water is available.
Often are pioneer species
Pioneer species – first plants to grow in new or
disturbed environments (lava fields, forest fire)

16. Seedless Vascular Plants
Have tube like cells of vascular tissue that
moves water and nutrients through the plant.
Grow larger than nonvascular plants b/c the
vascular tissue distributes water and nutrients.
Ex. – ferns, ground pines, spike mosses,
horsetails.
Ferns – largest group of seedless vascular
plants

17. Ferns
At least 12,000 known
species
Have stems, leaves, and
roots
Leaves are called
fronds.
Spores are produced in
structures that are
usually found on the
underside of the fronds.

18. Club Mosses
Have needle like
leaves
Spores are produced
at the end of the
stems in structures
that look like tiny pine
cones.

19. Horsetails
Stem is jointed and has a
hollow center surrounded
by a ring of vascular
tissue.
At each joint, leaves
grow out from around the
stem.
Pull on a stem, will pop
apart in sections.
Used for polishing
objects and sharpening
tools

20. Importance of Seedless Plants
Peat – compressed
decaying plants – used
as low-cost fuel in places
like Ireland and Russia.
Peat supplies about 1/3
of Ireland’s energy
requirements.

21. Chapter 5
Section 3
Seed Plants

22. Characteristics of Seed Plants
Most plants identified so far are seed plants.
Classified into 2 major groups – gymnosperms
and angiosperms
Seed plants are vascular

23. Characteristics of seed plants
Leaves – where photosynthesis usually occurs
Many different shapes, sizes, and colors

24. Characteristics of seed plants
Leaf cell layers
– epidermis (upper and lower surface)
– stomata – small openings in epidermis that
allows oxygen, water, and carbon dioxide to
enter and leave the cell.
– Guard cells – 2 found around each stoma
that opens and closes it

25. Characteristics of seed plants
Stems – located above ground and support
branches, leaves, and flowers.
Materials move between leaves and roots
through vascular tissue in the stem.
Can be herbaceous (soft and green) or woody
(hard and rigid)

26. Characteristics of seed plants
Roots – water and
other substances
enter through roots
Act as anchors
(hold plants in the
ground)
Store food

27. Characteristics of seed plants
Vascular Tissue – 3 types
Xylem – hollow, tubular cells that are stacked upon one
another to form a vessel. These vessels transport
water and substances from the roots to the rest of the
plant. Also help support plant.
Phloem – tubular cells that are stacked to form tubes.
Move food from where it’s made to other parts of the
plant.
Cambium – tissue that produces most of xylem and
phloem cells.

28. Gymnosperms
Oldest trees alive are gymnosperms and most
gymnosperms are conifers (trees that produce
cones).
Gymnosperm – vascular plants that produce
seeds NOT protected by fruit.
Do NOT have flowers
Leaves are needle like or scale like.
Many gymnosperms are called evergreens
because some leaves always remain on their
branches.

29. Reproductive Process of
Gymnosperms
Conifers produce seeds on the woody scales of
cones.
Female cones have spiral woody scales on a
short stem. Eggs are formed in 2 ovules on the
top of each scale.
Male cones are much smaller and less woody
than the female. They produce large amounts of
pollen.
Pollen is released and may land on female cone
and fertilizes the eggs.

30. Angiosperms
Flowering plants
Vascular plants that produce seeds inside fruits,
which form flowers.
Root system
Shoot system – stem and leaves
Flowers develop from the shoot system.

31. Parts of an Angiosperm

32. Parts of an Angiosperm
Pistils – female reproductive organ
Ovary – located at the base of the pistil
Ovules – structures that contain eggs
Stigma – sticky top part of the pistil

33. Parts of an Angiosperm
Style – a stalk that connects the ovule to the
stigma.
Stamen – male reproductive organ
Filament – stalk found in the stamen
Anther – on top of filament where pollen is
formed.
Petals – surround the pistils and stamens –
attract pollinators

34. Reproduction
Process of
Angiosperms
(sexual
reproduction)

35. Pollination
Occurs when pollen grains from the
anthers are carried by water, wind, or
animals to the stigma.
When a pollen grain lands on the sticky
stigma, a tube grows downward through
the style, into the ovary, and into the ovule.

36. Other types of Pollination
When pollen from When pollen from a
the anther of a flower on one plant
flower on one plant lands on the stigma
lands on the stigma of the same flower
of a flower from or on the stigma of
another plant, it is another flower on
called cross- the same plant, it is
pollination. called self-
pollination.

37. Fertilization
Occurs when a sperm cell from the pollen grain
moves down through the pollen tube and fuses
with an egg cell in the ovule.
Zygote is formed when the sperm cell and egg
cell join.
Zygote then develops into an embryo (young
growing plant).

38. Fertilization
As the embryo grows, the outer layers of the ovule
become tough and form a seed coat.
Seed coat protects the embryo after it is released into
the environment.
Seed – consists of the embryo, stored food, and seed
coat.
Ovary that surrounds a seed or seeds gets larger and
develops into the fruit.
Fruit – ripened ovary of a flower that contains one or
more seeds.

39. Seed Dispersal
When seeds are usually carried away from the
parent plant.
Fruits assist in seed dispersal, as well as in seed
protection.

40. What’s inside a seed?
Cotyledon – the young leaves in the embryo of
a seed.
Monocot – seed embryos that contain one
cotyledon (mono means “one”). Stored
nutrients for the growing embryo are located in
the endosperm (main part of a corn seed you
eat).
Dicot - seed embryos that contain 2 cotyledons
(di means “two”). Stored nutrients in dicot seeds
are located in the cotyledons. Cotyledons are
the main part of a bean seed you eat.

41. Germination
Early growth of a new plant from the embryo in a
seed.
Monocot flowers – petals and sepals are in
multiples of 3, leaves are narrow and contain
parallel veins.
Dicot flowers –petals and sepals are in
multiples of 4 or 5, leaves are broad and contain
branched veins.

42. Other Types of Reproduction
Asexual reproduction – reproduction by any
process that does NOT involve gametes (sperm
cells and egg cells).
Vegetative propagation (type of asexual
reproduction) – when a new plant can be grown
from parts of other plants.

43. Life Cycles of Angiosperms
Biennials – complete Perennials – take
their life cycles within more than 2 years to
2 years. They only complete their life
produce flowers and cycles. They produce
seeds and flowers
seeds during the 2 each spring.
year of growth.
Annuals – these must be grown from seeds each
year.

44. Importance of Seed Plants
No paper, no books, no pencils, no food if there
were no seed plants!!
Most of the wood used for construction and for
paper production comes from conifers such as
pine and spruces.
Basis for diets of most animals.
First plants that humans grew.
Source of many fibers in clothing.