Unit 5 : Diversity of Life
Content Outline: Plant Kingdom (5.6) – Part 1
I.
Characteristics that distinguish plants from other living things:
A. Plants are autotrophs, which means they make their own food (auto = self, troph = feeding)
1. They have a green pigment known as chlorophyll in their chloroplasts, which absorbs light energy
needed for photosynthesis.
2. Plants use the energy from light to make food from carbon dioxide in the atmosphere and water taken
up through their roots.
a. This process is photosynthesis.
3. Plants are also known as producers because they make their own food, and provide food for other
organisms.
B. All plants except green algae are multicellular, and their cells are organized into tissues.
C. Plant cells have specialized structures:
1. Plant cells have a cell wall outside the cell membrane that supports them and protects the plant cell.
2. Plant cells have specialized organelles called chloroplasts, which are the location of photosynthesis.
3. Plant cells have large storage sacs called vacuoles that store water, wastes, food, and helps support
the cell.
Unit 5 : Diversity of Life
Content Outline: Plant Kingdom (5.6) – Part 2
I.
Plants are divided into two major groups, with one of those groups divided further into three groups.
A. Nonvascular plants
1. These plants do not have specialized vascular tissue to transport nutrients, water, and food.
2. They are small organisms made of few cells, materials move from cell to cell by absorption and diffusion.
3. They are collectively known as Bryophytes (mosses, liverworts, hornworts).
4. They live in damp locations.
B. Vascular plants
1. The seedless vascular plants known as Pteriodophytes.
2. Vascular plants that produce seeds but no flowers, known as gymnosperms.
3. Vascular plants that produce seeds and flowers, known as angiosperms.
4. Three major groups of vascular plants evolved over millions of years in response to the changing
environment. They are:
a. Pteriodophytes (Vascular, non-seed plants)
i. They reproduce by spores, not seeds.
ii. This group includes ferns, horsetails, and club mosses.
iii. They have specialized vascular tissue for transporting materials, and true roots
and stems.
b. Gymnosperms (Vascular, “naked seed” plants)
i. Dispersal of the plants increases with the evolution of the seed.
ii. Seeds can be “moved” into new territory – away from competition.
c. Angiosperms (Vascular, flowering plants)
i. Flowers and fruit - These structures help the plant survive moving to new areas
or reproducing by using animals to disperse seed.
5. They have vascular tissue to transport water, nutrients, wastes, and food through the whole plant.
a. They are larger than nonvascular plants since water & food can be transported over long
distances.
b. Vascular tissue also strengthens the plant.
c. There are two types of vascular tissue:
i. Phloem – carries food from the leaves where it is made by photosynthesis to all
other parts of the plant.
ii. Xylem – carries water and minerals from the roots upward to all other parts of
the plant.
Unit 5 : Diversity of Life
Content Outline: Plant Kingdom (5.6) – Part 3
I.
Seed Plants - Characteristics of Seed Plants:
A. All seed plants have two characteristics:
1. Vascular tissue for transport of water, nutrients, food.
a. All seed plants have true roots, stems and leaves.
b. Most seed plants live on land.
2. Reproduce by using pollen and seeds.
a. Seed plants do not need a moist environment to reproduce.
b. Seed plants produce pollen, which contains cells that will become sperm.
c. Pollen fertilizes the egg cells, and seeds develop.
d. Seeds are structures that contain young plants and protect them until conditions for growth are good.
B. Two main groups of seed plants exist: gymnosperms and angiosperms
1. Gymnosperms “Naked Seed Plants”
a. Adaptations needed for much drier and cooler environments:
i. Reduced size of leaves. (The leaves of pines are called needles.)
ii. Thick, waxy cuticle on the leaves.
iii. The leaves remain all year, hence the term “evergreens”. They shed a little at a time, like a dog
sheds hair.
iv. Large plants with thick bark.
v. Two types of cones for reproduction. The female cones (large and hard) contain the seeds. Males
(small and yellow) contain the pollen grains that contain the sperm.
 The wind and rain carry the pollen grains to the female cones for fertilization.
 Seeds have a food source for the developing embryo inside. Seeds are not enclosed in fruits.
b. Four types of gymnosperms exist today:
i. Cycads – looks like a palm tree, with cones as large as a football.
ii. Ginkgoes - the Ginkgo tree is the only species existing. Has “fan shaped” leaves that turn yellow
and drop in the fall.
iii. Conifers – largest & most diverse group of gymnosperms; most are evergreen & keep their
needles all year. Pine trees are a common example.
iv. Gnetophytes – live in hot deserts and tropical rain forests. Some are trees, some shrubs, some
vines.
Unit 5 : Diversity of Life
Content Outline: Plant Kingdom (5.6) – Part 4
I.
Angiosperms – “flowering plants”
A. All angiosperms produce flowers.
1. Flowers have four circles of specialized, modified leaves:
 Sepals – These are the green protective leaves. (Form the bud.)(They are non-reproductive.)
 Petals – These are the colored attractant leaves. (They are fragrant and also nonreproductive.)
 Stamen- This is the male structure producing reproductive cells. Site of pollen grains. (It is
reproductive.)
 Anther -Part with the yellow pollen grains; and filament - It is a support stalk.
 Pollinator (animal or insect) to transport pollen grain. (This is an example of coevolution
and this reduces competition for each organism.)
 Carpel/Pistil – Site of female reproductive structures: (It is reproductive.)
 Stigma (sticky top), Style (the neck), ovary (Contains the ovules and eggs.)
B. All angiosperms produce seed enclosed in fruits.
C. All angiosperms produce Fruit (It is a ripened ovary.) Developed to promote seed dispersal by animals
eating the fruit.
1. Green fruit (unripened, hard, unscented, and sour – no sugar.)
2. Colored fruit (ripened, soft, scented, and sweet – lots of sugar.)(pericarp – skin of the
carpel/fruit.)
3. After fertilization the ovary wall thickens to become pulp of the fruit. (Inside are the seeds.)
D. Angiosperms are divided into two groups, based mainly on their seed, leaf and stem structure:
1. Monocots – The cotyledon is the part of the seed that provides food for the embryo. Monocots
have a one-part seed that does not split in two easily.
a. Grasses, including corn, are examples.
2. Dicots – the cotyledon is in two pieces, and splits easily.
a. Examples are pistachios, peanuts, English peas, apples, oaks and maple trees.