1.Why do you think that plants such as these are essential for most life on Earth?

2. In what major way does the top pair of plants differ from the bottom pair?

Plants

The Diversity of Plants

Nonvascular Plants

Non-Seed Vascular Plants

• Nonvascular plants are mosses, liverworts and hornworts.

What is a nonvascular plant?What is a nonvascular plant?

• Nonvascular plants can only pass materials from one cell to the next.

What is a nonvascular plant?What is a nonvascular plant?

• Nonvascular plants only have their cell walls to provide support, so they are small, low plants.

• Nonvascular plants lack roots, but can obtain water and minerals from their surroundings.

• Nonvascular plants can only grow in moist environments because they must have a thin film of water for sperm to reach the egg.

• Nonvascular plants produce spores.

Alternation of generationsAlternation of generations

• There are several divisions of nonvascular plants.

• The first division you’ll study are the mosses, or bryophytes.

• Mosses are small plants with leafy stems.

Adaptations in BryophytaAdaptations in Bryophyta

Adaptations in BryophytaAdaptations in Bryophyta

• Mosses usually grow in dense carpets of hundreds of plants.

• The leaves of mosses are usually one cell thick.

Adaptations in HepaticophytaAdaptations in Hepaticophyta

• Another division of nonvascular plants is the liverworts, or hepaticophytes.

• Liverworts are small plants that usually grow in clumps or masses in moist habitats.

Adaptations in AnthocerophytaAdaptations in Anthocerophyta

• Anthocerophytes are the smallest division of nonvascular plants, currently consisting of only about 100 species.

• Also known as hornworts, these nonvascular plants are similar to liverworts in several respects.

What is a non-seed vascular plant?What is a non-seed vascular plant?• The obvious difference between a vascular

and a nonvascular plant is the presence of vascular tissue.

• Ferns, club mosses and horsetails are non-seed vascular plants.

• Ferns, club mosses and horsetails reproduce using spores and still need to grow in moist surroundings.

Fern StructuresFern Structures• In most

ferns, the main stem is underground.

• A rhizome is the thick, underground stem of a fern

Fronds

Root

Rhizome

• The leaves of a fern are called fronds and grow upward from the rhizome.

• Spores develop on the underside of mature fronds.

Fern StructuresFern Structures

Adaptations in

Lycophyta

Adaptations in

Lycophyta

• Lycophytes are commonly called club mosses and spike mosses.

Adaptations in

Arthrophyta

Adaptations in

Arthrophyta

• Arthrophytes, or horsetails, represent a second group of ancient vascular plants.

• Ferns range in size from a few meters tall, like tree ferns, to small, floating plants that are only a few centimeters in diameter.

Adaptations in PterophytaAdaptations in Pterophyta

Question 1

The only plants that have a dominant gametophyte generation are the _______.

D. ferns

C. nonvascular plants

B. flowering plants

A. vascular plants

The answer is C.

Question 2

The rhizoid in mosses has a function comparable to _______.

D. The leaf in cycads

C. The root in vascular plants

B. The cone in conifers

A. The flower in flowering plants

The answer is C. Rhizoids anchor the stems of mosses to the soil as roots do in other plants.

Using the figure, which structure would you assume the sporophyte grows from?

Question 1Egg

Archegonium

Antheridium

Sperm Rhizoids

Prothallus

The answer is the archegonium. Sperm travel from the antheridium to the archegonium where they unite with an egg and form a zygote. The zygote grows into the sporophyte.

Egg

Archegonium

Antheridium

Sperm Rhizoids

Prothallus

A compact cluster of spore-bearing leaves is called a _______.

D. strobilus

C. prothallus

B. rhizoid

A. thallus

The answer is D.

Question 2

1. How are these cones similar?2. What is their function?

Plants

The Diversity of Plants

That Characteristics of Seed Plants

• All seed plants have vascular tissue, use seed to reproduce and have leaves, stems and roots.

What is a seed plant?

• Seed plants do not need water in their environment to reproduce.

Reproductive strategiesReproductive strategies

•Embryo

•Seed Coat

•Food Supply

• A seed is a plant organ that contains an embryo, along with a food supply, and is covered by a protective coat.

• The embryo is a fertilized egg that the young plant develops from

• Embryos of seed plants include one or more cotyledons (seed leaves).

Fertilization and reproduction

• Cotyledons store or absorb food for the developing embryo.

Seed coat

Cotyledon

Cotyledons

Fertilization and reproduction

Advantages of seeds• The seed coat is the

outer covering of the seed.

• Ex. “skins” on peanuts, beans, etc.

• The scattering of seeds is called seed dispersal.

Embryo

Seed coat

Food supply

Seed Dispersal• Some seeds are spiny and

hitch rids on the fur of animals.

• Some seeds rely on oceans, rivers and streams of dispersal.

• The wind carries some seeds through the air.

• Some plants shoot their seeds out when their pods explode.

• Some rely on animals to eat them and pass them out later. Ex. acorn or apple

What are gymnosperms?• Gymnosperms are plants

whose seeds are not protected by a fruit.

• Many gymnosperms have needlelike or scalelike leaves.

• Most gymnosperms are trees, a few are shrubs or vines.

Cycads

• Grow mainly in tropical and subtropical areas.

• Look like palm trees with cones.

• All ginkgoes are cultivated trees, and they are not known to exist in the wild.

• Only one species exists.

Gingko

• Ginkgoes often are planted in urban areas because they tolerate smog and pollution.

Gnetophytes• Found only in the hot, dry

deserts of South Africa, deserts of the western United States, and the tropical rain forests.

• The plants that grow in South Africa grow close to the ground, have large tuberous roots, and may live 1000 years.

Confiers• Cone-bearing plants

• Cones are either male or female

• Some trees produce both cones, some only produce one

• Largest and most diverse group of gymnosperms

• Most are evergreen

Deciduous trees lose their leaves

• A few conifers are deciduous.

• Deciduous plants drop all their leaves each fall or when water is scarce or unavailable.

Diversity of seed plants

• Flowering plants, also called angiosperms, produce seeds enclosed within a fruit.

• The fruit is the ripened ovary of a flower.

Diversity of seed plants

• The fruit provides protection for seeds and aids in seed dispersal.

• The Anthophyta division contains all species of flowering plants.

The structure of a flowerThe structure of a flower

• The flower contains the reproductive structures that the fruit develops from.

Seed plants produce spores• The male structure is the stamen, which

consists of a filament and an anther where the pollen grains are produced.

antherfilament stamen

Seed plants produce spores• The pollen grain is the male gametophyte

that includes sperm cells, nutrients, and a protective outer covering.

antherfilament stamen

• The female structure is the pistil, which consists of the stigma, style, and ovary where the ovule is produced.

stigma

style

ovaryovule

pistil

antherfilament stamen

Seed plants produce spores

• The ovule is the structure that contains the female gametophyte, which produces the egg cell.

stigma

style

ovaryovule

pistil

antherfilament stamen

Seed plants produce spores

• The division Anthophyta is divided into two classes: monocotyledons and dicotyledons.

• Monocotyledons have one seed leaf.

• Dicotyledons have two seed leaves.

Moncots and dicots

• Xylem and phloem are located in the center of the root.

• The arrangement of xylem and phloem tissues accounts for one of the major differences between monocots and dicots.

•Root hairs

•Xylem

•Phloem

•Pericycle

•Endodermis

•Apical meristem

•Root cap

•The structure of roots•The structure of roots

• In dicot roots, the xylem forms a central star-shaped mass with phloem cells between the rays of the star.

•The structure of roots•The structure of roots

The structure of roots

• Monocot roots usually have strands of xylem that alternate with strands of phloem.

• In most dicots, xylem and phloem are in a circle of vascular bundles that form a ring in the cortex.

•Vascular bundle

•Internal structure•Internal structure

Internal structure• The vascular bundles of most

monocots are scattered throughout the stem.

•Vascular bundles

• Petals in multiples of 3

• Parallel network of veins

• include grasses, orchids, lilies, and palms.

Moncots

• Network of veins

• Petals of multiples of 4 or 5

• nearly all of the familiar shrubs and trees (except conifers), cacti, wildflowers, garden flowers, vegetables, and herbs.

Dicots

Moncots and dicotsDistinguishing Characteristics of Monocots and Dicots

Seed LeavesVascular Bundles in Leaves

Vascular Bundles in Stems

Flower Parts

Monocots

Dicots

One cotyledon Usually parallel Scattered Multiples of three

Two cotyledons

Usually netlike Arranged in ring Multiples of four and five

Fold the paper widthwise into fourths.

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Unfold, lay the paper lengthwise, and draw lines along the folds.

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Label your table as shown.

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A pollen grain contains a _______.

Question 1

D. sporophyte

C. gametophyte

B. embryo

A. seed

The answer is C.

Why are seeds adapted for easy dispersal to new areas an advantage for plants?

Answer

When the seeds germinate in new areas, the new plants do not have to compete with the parent plant for sunlight, water, soil nutrients, and living space.

Question 2

The strobilus in some non-seed vascular plants is comparable to what in gymnosperms?

D. ovule

C. pollen grain

B. cone

A. seed

The answer is B.

Question 3

Which of the following is not an advantage for evergreen conifers?

A. They can photosynthesize whenever favorable environmental conditions exist.

B. Their food reserves are not depleted each spring to produce a whole set of new leaves.

Question 2

Which of the following is not an advantage for evergreen conifers?

D. Their leaf shape helps reduce water loss.

C. Their fruit protect their seeds against harsh environmental conditions.

Question 2

The answer is C. Conifers have naked seeds with no fruit.

Why is winter an optimal time for deciduous plants to have no leaves?

Answer

Less water is available to plants in winter, so they must reduce water loss, the most of which is through leaves. Sunlight is reduced as well, so leaves would not photosynthesize as much in winter.

Question 3